diff --git a/.clang-format b/.clang-format
index 8e0fd8b014..9b17129ce6 100644
--- a/.clang-format
+++ b/.clang-format
@@ -9,11 +9,28 @@ BinPackParameters: false
 BreakBeforeBinaryOperators: All
 BreakConstructorInitializers: BeforeColon
 ColumnLimit: 99
+IncludeBlocks: Regroup
 IndentCaseLabels: true
 IndentPPDirectives: AfterHash
 IndentWidth: 4
 Language: Cpp
+ReflowComments: false
 SpaceAfterCStyleCast: true
 Standard: Cpp11
 TabWidth: 4
+IncludeCategories:
+  - Regex:           '<pybind11/.*'
+    Priority:        -1
+  - Regex:           'pybind11.h"$'
+    Priority:        1
+  - Regex:           '^".*/?detail/'
+    Priority:        1
+    SortPriority:    2
+  - Regex:           '^"'
+    Priority:        1
+    SortPriority:    3
+  - Regex:           '<[[:alnum:]._]+>'
+    Priority:        4
+  - Regex:           '.*'
+    Priority:        5
 ...
diff --git a/.clang-tidy b/.clang-tidy
index d853a703ce..34237d9d42 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -39,6 +39,7 @@ readability-implicit-bool-conversion,
 readability-make-member-function-const,
 readability-misplaced-array-index,
 readability-non-const-parameter,
+readability-qualified-auto,
 readability-redundant-function-ptr-dereference,
 readability-redundant-smartptr-get,
 readability-redundant-string-cstr,
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 2014cb2b42..c31cab71c7 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -141,11 +141,7 @@ repos:
     entry: PyBind|Numpy|Cmake|CCache|PyTest
     exclude: .pre-commit-config.yaml
 
-- repo: local
+- repo: https://github.com/pre-commit/mirrors-clang-format
+  rev: "v13.0.0"
   hooks:
-  - id: check-style
-    name: Classic check-style
-    language: system
-    types:
-    - c++
-    entry: ./tools/check-style.sh
+  - id: clang-format
diff --git a/include/pybind11/attr.h b/include/pybind11/attr.h
index f1b66fb80c..3a6d6cc421 100644
--- a/include/pybind11/attr.h
+++ b/include/pybind11/attr.h
@@ -20,54 +20,62 @@ PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 /// @{
 
 /// Annotation for methods
-struct is_method { handle class_;
+struct is_method {
+    handle class_;
     explicit is_method(const handle &c) : class_(c) {}
 };
 
 /// Annotation for operators
-struct is_operator { };
+struct is_operator {};
 
 /// Annotation for classes that cannot be subclassed
-struct is_final { };
+struct is_final {};
 
 /// Annotation for parent scope
-struct scope { handle value;
+struct scope {
+    handle value;
     explicit scope(const handle &s) : value(s) {}
 };
 
 /// Annotation for documentation
-struct doc { const char *value;
+struct doc {
+    const char *value;
     explicit doc(const char *value) : value(value) {}
 };
 
 /// Annotation for function names
-struct name { const char *value;
+struct name {
+    const char *value;
     explicit name(const char *value) : value(value) {}
 };
 
 /// Annotation indicating that a function is an overload associated with a given "sibling"
-struct sibling { handle value;
+struct sibling {
+    handle value;
     explicit sibling(const handle &value) : value(value.ptr()) {}
 };
 
 /// Annotation indicating that a class derives from another given type
-template <typename T> struct base {
+template <typename T>
+struct base {
 
-    PYBIND11_DEPRECATED("base<T>() was deprecated in favor of specifying 'T' as a template argument to class_")
-    base() { } // NOLINT(modernize-use-equals-default): breaks MSVC 2015 when adding an attribute
+    PYBIND11_DEPRECATED(
+        "base<T>() was deprecated in favor of specifying 'T' as a template argument to class_")
+    base() {} // NOLINT(modernize-use-equals-default): breaks MSVC 2015 when adding an attribute
 };
 
 /// Keep patient alive while nurse lives
-template <size_t Nurse, size_t Patient> struct keep_alive { };
+template <size_t Nurse, size_t Patient>
+struct keep_alive {};
 
 /// Annotation indicating that a class is involved in a multiple inheritance relationship
-struct multiple_inheritance { };
+struct multiple_inheritance {};
 
 /// Annotation which enables dynamic attributes, i.e. adds `__dict__` to a class
-struct dynamic_attr { };
+struct dynamic_attr {};
 
 /// Annotation which enables the buffer protocol for a type
-struct buffer_protocol { };
+struct buffer_protocol {};
 
 /// Annotation which requests that a special metaclass is created for a type
 struct metaclass {
@@ -78,7 +86,7 @@ struct metaclass {
     metaclass() {}
 
     /// Override pybind11's default metaclass
-    explicit metaclass(handle value) : value(value) { }
+    explicit metaclass(handle value) : value(value) {}
 };
 
 /// Specifies a custom callback with signature `void (PyHeapTypeObject*)` that
@@ -99,15 +107,16 @@ struct custom_type_setup {
 };
 
 /// Annotation that marks a class as local to the module:
-struct module_local { const bool value;
+struct module_local {
+    const bool value;
     constexpr explicit module_local(bool v = true) : value(v) {}
 };
 
 /// Annotation to mark enums as an arithmetic type
-struct arithmetic { };
+struct arithmetic {};
 
 /// Mark a function for addition at the beginning of the existing overload chain instead of the end
-struct prepend { };
+struct prepend {};
 
 /** \rst
     A call policy which places one or more guard variables (``Ts...``) around the function call.
@@ -127,9 +136,13 @@ struct prepend { };
             return foo(args...); // forwarded arguments
         });
  \endrst */
-template <typename... Ts> struct call_guard;
+template <typename... Ts>
+struct call_guard;
 
-template <> struct call_guard<> { using type = detail::void_type; };
+template <>
+struct call_guard<> {
+    using type = detail::void_type;
+};
 
 template <typename T>
 struct call_guard<T> {
@@ -154,7 +167,8 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 enum op_id : int;
 enum op_type : int;
 struct undefined_t;
-template <op_id id, op_type ot, typename L = undefined_t, typename R = undefined_t> struct op_;
+template <op_id id, op_type ot, typename L = undefined_t, typename R = undefined_t>
+struct op_;
 void keep_alive_impl(size_t Nurse, size_t Patient, function_call &call, handle ret);
 
 /// Internal data structure which holds metadata about a keyword argument
@@ -166,15 +180,16 @@ struct argument_record {
     bool none : 1;     ///< True if None is allowed when loading
 
     argument_record(const char *name, const char *descr, handle value, bool convert, bool none)
-        : name(name), descr(descr), value(value), convert(convert), none(none) { }
+        : name(name), descr(descr), value(value), convert(convert), none(none) {}
 };
 
-/// Internal data structure which holds metadata about a bound function (signature, overloads, etc.)
+/// Internal data structure which holds metadata about a bound function (signature, overloads,
+/// etc.)
 struct function_record {
     function_record()
         : is_constructor(false), is_new_style_constructor(false), is_stateless(false),
-          is_operator(false), is_method(false), has_args(false),
-          has_kwargs(false), prepend(false) { }
+          is_operator(false), is_method(false), has_args(false), has_kwargs(false),
+          prepend(false) {}
 
     /// Function name
     char *name = nullptr; /* why no C++ strings? They generate heavier code.. */
@@ -189,13 +204,13 @@ struct function_record {
     std::vector<argument_record> args;
 
     /// Pointer to lambda function which converts arguments and performs the actual call
-    handle (*impl) (function_call &) = nullptr;
+    handle (*impl)(function_call &) = nullptr;
 
     /// Storage for the wrapped function pointer and captured data, if any
-    void *data[3] = { };
+    void *data[3] = {};
 
     /// Pointer to custom destructor for 'data' (if needed)
-    void (*free_data) (function_record *ptr) = nullptr;
+    void (*free_data)(function_record *ptr) = nullptr;
 
     /// Return value policy associated with this function
     return_value_policy policy = return_value_policy::automatic;
@@ -251,7 +266,7 @@ struct function_record {
 struct type_record {
     PYBIND11_NOINLINE type_record()
         : multiple_inheritance(false), dynamic_attr(false), buffer_protocol(false),
-          default_holder(true), module_local(false), is_final(false) { }
+          default_holder(true), module_local(false), is_final(false) {}
 
     /// Handle to the parent scope
     handle scope;
@@ -310,22 +325,22 @@ struct type_record {
     /// Is the class inheritable from python classes?
     bool is_final : 1;
 
-    PYBIND11_NOINLINE void add_base(const std::type_info &base, void *(*caster)(void *)) {
-        auto base_info = detail::get_type_info(base, false);
+    PYBIND11_NOINLINE void add_base(const std::type_info &base, void *(*caster)(void *) ) {
+        auto *base_info = detail::get_type_info(base, false);
         if (!base_info) {
             std::string tname(base.name());
             detail::clean_type_id(tname);
-            pybind11_fail("generic_type: type \"" + std::string(name) +
-                          "\" referenced unknown base type \"" + tname + "\"");
+            pybind11_fail("generic_type: type \"" + std::string(name)
+                          + "\" referenced unknown base type \"" + tname + "\"");
         }
 
         if (default_holder != base_info->default_holder) {
             std::string tname(base.name());
             detail::clean_type_id(tname);
-            pybind11_fail("generic_type: type \"" + std::string(name) + "\" " +
-                    (default_holder ? "does not have" : "has") +
-                    " a non-default holder type while its base \"" + tname + "\" " +
-                    (base_info->default_holder ? "does not" : "does"));
+            pybind11_fail("generic_type: type \"" + std::string(name) + "\" "
+                          + (default_holder ? "does not have" : "has")
+                          + " a non-default holder type while its base \"" + tname + "\" "
+                          + (base_info->default_holder ? "does not" : "does"));
         }
 
         bases.append((PyObject *) base_info->type);
@@ -338,14 +353,13 @@ struct type_record {
     }
 };
 
-inline function_call::function_call(const function_record &f, handle p) :
-        func(f), parent(p) {
+inline function_call::function_call(const function_record &f, handle p) : func(f), parent(p) {
     args.reserve(f.nargs);
     args_convert.reserve(f.nargs);
 }
 
 /// Tag for a new-style `__init__` defined in `detail/init.h`
-struct is_new_style_constructor { };
+struct is_new_style_constructor {};
 
 /**
  * Partial template specializations to process custom attributes provided to
@@ -353,74 +367,95 @@ struct is_new_style_constructor { };
  * fields in the type_record and function_record data structures or executed at
  * runtime to deal with custom call policies (e.g. keep_alive).
  */
-template <typename T, typename SFINAE = void> struct process_attribute;
+template <typename T, typename SFINAE = void>
+struct process_attribute;
 
-template <typename T> struct process_attribute_default {
+template <typename T>
+struct process_attribute_default {
     /// Default implementation: do nothing
-    static void init(const T &, function_record *) { }
-    static void init(const T &, type_record *) { }
-    static void precall(function_call &) { }
-    static void postcall(function_call &, handle) { }
+    static void init(const T &, function_record *) {}
+    static void init(const T &, type_record *) {}
+    static void precall(function_call &) {}
+    static void postcall(function_call &, handle) {}
 };
 
 /// Process an attribute specifying the function's name
-template <> struct process_attribute<name> : process_attribute_default<name> {
+template <>
+struct process_attribute<name> : process_attribute_default<name> {
     static void init(const name &n, function_record *r) { r->name = const_cast<char *>(n.value); }
 };
 
 /// Process an attribute specifying the function's docstring
-template <> struct process_attribute<doc> : process_attribute_default<doc> {
+template <>
+struct process_attribute<doc> : process_attribute_default<doc> {
     static void init(const doc &n, function_record *r) { r->doc = const_cast<char *>(n.value); }
 };
 
 /// Process an attribute specifying the function's docstring (provided as a C-style string)
-template <> struct process_attribute<const char *> : process_attribute_default<const char *> {
+template <>
+struct process_attribute<const char *> : process_attribute_default<const char *> {
     static void init(const char *d, function_record *r) { r->doc = const_cast<char *>(d); }
     static void init(const char *d, type_record *r) { r->doc = const_cast<char *>(d); }
 };
-template <> struct process_attribute<char *> : process_attribute<const char *> { };
+template <>
+struct process_attribute<char *> : process_attribute<const char *> {};
 
 /// Process an attribute indicating the function's return value policy
-template <> struct process_attribute<return_value_policy> : process_attribute_default<return_value_policy> {
+template <>
+struct process_attribute<return_value_policy> : process_attribute_default<return_value_policy> {
     static void init(const return_value_policy &p, function_record *r) { r->policy = p; }
 };
 
-/// Process an attribute which indicates that this is an overloaded function associated with a given sibling
-template <> struct process_attribute<sibling> : process_attribute_default<sibling> {
+/// Process an attribute which indicates that this is an overloaded function associated with a
+/// given sibling
+template <>
+struct process_attribute<sibling> : process_attribute_default<sibling> {
     static void init(const sibling &s, function_record *r) { r->sibling = s.value; }
 };
 
 /// Process an attribute which indicates that this function is a method
-template <> struct process_attribute<is_method> : process_attribute_default<is_method> {
-    static void init(const is_method &s, function_record *r) { r->is_method = true; r->scope = s.class_; }
+template <>
+struct process_attribute<is_method> : process_attribute_default<is_method> {
+    static void init(const is_method &s, function_record *r) {
+        r->is_method = true;
+        r->scope = s.class_;
+    }
 };
 
 /// Process an attribute which indicates the parent scope of a method
-template <> struct process_attribute<scope> : process_attribute_default<scope> {
+template <>
+struct process_attribute<scope> : process_attribute_default<scope> {
     static void init(const scope &s, function_record *r) { r->scope = s.value; }
 };
 
 /// Process an attribute which indicates that this function is an operator
-template <> struct process_attribute<is_operator> : process_attribute_default<is_operator> {
+template <>
+struct process_attribute<is_operator> : process_attribute_default<is_operator> {
     static void init(const is_operator &, function_record *r) { r->is_operator = true; }
 };
 
-template <> struct process_attribute<is_new_style_constructor> : process_attribute_default<is_new_style_constructor> {
-    static void init(const is_new_style_constructor &, function_record *r) { r->is_new_style_constructor = true; }
+template <>
+struct process_attribute<is_new_style_constructor>
+    : process_attribute_default<is_new_style_constructor> {
+    static void init(const is_new_style_constructor &, function_record *r) {
+        r->is_new_style_constructor = true;
+    }
 };
 
 inline void check_kw_only_arg(const arg &a, function_record *r) {
     if (r->args.size() > r->nargs_pos && (!a.name || a.name[0] == '\0'))
-        pybind11_fail("arg(): cannot specify an unnamed argument after a kw_only() annotation or args() argument");
+        pybind11_fail("arg(): cannot specify an unnamed argument after a kw_only() annotation or "
+                      "args() argument");
 }
 
 inline void append_self_arg_if_needed(function_record *r) {
     if (r->is_method && r->args.empty())
-        r->args.emplace_back("self", nullptr, handle(), /*convert=*/ true, /*none=*/ false);
+        r->args.emplace_back("self", nullptr, handle(), /*convert=*/true, /*none=*/false);
 }
 
 /// Process a keyword argument attribute (*without* a default value)
-template <> struct process_attribute<arg> : process_attribute_default<arg> {
+template <>
+struct process_attribute<arg> : process_attribute_default<arg> {
     static void init(const arg &a, function_record *r) {
         append_self_arg_if_needed(r);
         r->args.emplace_back(a.name, nullptr, handle(), !a.flag_noconvert, a.flag_none);
@@ -430,26 +465,30 @@ template <> struct process_attribute<arg> : process_attribute_default<arg> {
 };
 
 /// Process a keyword argument attribute (*with* a default value)
-template <> struct process_attribute<arg_v> : process_attribute_default<arg_v> {
+template <>
+struct process_attribute<arg_v> : process_attribute_default<arg_v> {
     static void init(const arg_v &a, function_record *r) {
         if (r->is_method && r->args.empty())
-            r->args.emplace_back("self", /*descr=*/ nullptr, /*parent=*/ handle(), /*convert=*/ true, /*none=*/ false);
+            r->args.emplace_back(
+                "self", /*descr=*/nullptr, /*parent=*/handle(), /*convert=*/true, /*none=*/false);
 
         if (!a.value) {
 #if !defined(NDEBUG)
             std::string descr("'");
-            if (a.name) descr += std::string(a.name) + ": ";
+            if (a.name)
+                descr += std::string(a.name) + ": ";
             descr += a.type + "'";
             if (r->is_method) {
                 if (r->name)
-                    descr += " in method '" + (std::string) str(r->scope) + "." + (std::string) r->name + "'";
+                    descr += " in method '" + (std::string) str(r->scope) + "."
+                             + (std::string) r->name + "'";
                 else
                     descr += " in method of '" + (std::string) str(r->scope) + "'";
             } else if (r->name) {
                 descr += " in function '" + (std::string) r->name + "'";
             }
-            pybind11_fail("arg(): could not convert default argument "
-                          + descr + " into a Python object (type not registered yet?)");
+            pybind11_fail("arg(): could not convert default argument " + descr
+                          + " into a Python object (type not registered yet?)");
 #else
             pybind11_fail("arg(): could not convert default argument "
                           "into a Python object (type not registered yet?). "
@@ -463,29 +502,34 @@ template <> struct process_attribute<arg_v> : process_attribute_default<arg_v> {
 };
 
 /// Process a keyword-only-arguments-follow pseudo argument
-template <> struct process_attribute<kw_only> : process_attribute_default<kw_only> {
+template <>
+struct process_attribute<kw_only> : process_attribute_default<kw_only> {
     static void init(const kw_only &, function_record *r) {
         append_self_arg_if_needed(r);
         if (r->has_args && r->nargs_pos != static_cast<std::uint16_t>(r->args.size()))
-            pybind11_fail("Mismatched args() and kw_only(): they must occur at the same relative argument location (or omit kw_only() entirely)");
+            pybind11_fail("Mismatched args() and kw_only(): they must occur at the same relative "
+                          "argument location (or omit kw_only() entirely)");
         r->nargs_pos = static_cast<std::uint16_t>(r->args.size());
     }
 };
 
 /// Process a positional-only-argument maker
-template <> struct process_attribute<pos_only> : process_attribute_default<pos_only> {
+template <>
+struct process_attribute<pos_only> : process_attribute_default<pos_only> {
     static void init(const pos_only &, function_record *r) {
         append_self_arg_if_needed(r);
         r->nargs_pos_only = static_cast<std::uint16_t>(r->args.size());
         if (r->nargs_pos_only > r->nargs_pos)
             pybind11_fail("pos_only(): cannot follow a py::args() argument");
-            // It also can't follow a kw_only, but a static_assert in pybind11.h checks that
+        // It also can't follow a kw_only, but a static_assert in pybind11.h checks that
     }
 };
 
-/// Process a parent class attribute.  Single inheritance only (class_ itself already guarantees that)
+/// Process a parent class attribute.  Single inheritance only (class_ itself already guarantees
+/// that)
 template <typename T>
-struct process_attribute<T, enable_if_t<is_pyobject<T>::value>> : process_attribute_default<handle> {
+struct process_attribute<T, enable_if_t<is_pyobject<T>::value>>
+    : process_attribute_default<handle> {
     static void init(const handle &h, type_record *r) { r->bases.append(h); }
 };
 
@@ -498,7 +542,9 @@ struct process_attribute<base<T>> : process_attribute_default<base<T>> {
 /// Process a multiple inheritance attribute
 template <>
 struct process_attribute<multiple_inheritance> : process_attribute_default<multiple_inheritance> {
-    static void init(const multiple_inheritance &, type_record *r) { r->multiple_inheritance = true; }
+    static void init(const multiple_inheritance &, type_record *r) {
+        r->multiple_inheritance = true;
+    }
 };
 
 template <>
@@ -544,34 +590,41 @@ template <>
 struct process_attribute<arithmetic> : process_attribute_default<arithmetic> {};
 
 template <typename... Ts>
-struct process_attribute<call_guard<Ts...>> : process_attribute_default<call_guard<Ts...>> { };
+struct process_attribute<call_guard<Ts...>> : process_attribute_default<call_guard<Ts...>> {};
 
 /**
  * Process a keep_alive call policy -- invokes keep_alive_impl during the
  * pre-call handler if both Nurse, Patient != 0 and use the post-call handler
  * otherwise
  */
-template <size_t Nurse, size_t Patient> struct process_attribute<keep_alive<Nurse, Patient>> : public process_attribute_default<keep_alive<Nurse, Patient>> {
+template <size_t Nurse, size_t Patient>
+struct process_attribute<keep_alive<Nurse, Patient>>
+    : public process_attribute_default<keep_alive<Nurse, Patient>> {
     template <size_t N = Nurse, size_t P = Patient, enable_if_t<N != 0 && P != 0, int> = 0>
-    static void precall(function_call &call) { keep_alive_impl(Nurse, Patient, call, handle()); }
+    static void precall(function_call &call) {
+        keep_alive_impl(Nurse, Patient, call, handle());
+    }
     template <size_t N = Nurse, size_t P = Patient, enable_if_t<N != 0 && P != 0, int> = 0>
-    static void postcall(function_call &, handle) { }
+    static void postcall(function_call &, handle) {}
     template <size_t N = Nurse, size_t P = Patient, enable_if_t<N == 0 || P == 0, int> = 0>
-    static void precall(function_call &) { }
+    static void precall(function_call &) {}
     template <size_t N = Nurse, size_t P = Patient, enable_if_t<N == 0 || P == 0, int> = 0>
-    static void postcall(function_call &call, handle ret) { keep_alive_impl(Nurse, Patient, call, ret); }
+    static void postcall(function_call &call, handle ret) {
+        keep_alive_impl(Nurse, Patient, call, ret);
+    }
 };
 
 /// Recursively iterate over variadic template arguments
-template <typename... Args> struct process_attributes {
-    static void init(const Args&... args, function_record *r) {
+template <typename... Args>
+struct process_attributes {
+    static void init(const Args &...args, function_record *r) {
         PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(r);
         PYBIND11_WORKAROUND_INCORRECT_GCC_UNUSED_BUT_SET_PARAMETER(r);
         using expander = int[];
         (void) expander{
             0, ((void) process_attribute<typename std::decay<Args>::type>::init(args, r), 0)...};
     }
-    static void init(const Args&... args, type_record *r) {
+    static void init(const Args &...args, type_record *r) {
         PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(r);
         PYBIND11_WORKAROUND_INCORRECT_GCC_UNUSED_BUT_SET_PARAMETER(r);
         using expander = int[];
@@ -603,7 +656,7 @@ using extract_guard_t = typename exactly_one_t<is_call_guard, call_guard<>, Extr
 /// Check the number of named arguments at compile time
 template <typename... Extra,
           size_t named = constexpr_sum(std::is_base_of<arg, Extra>::value...),
-          size_t self  = constexpr_sum(std::is_same<is_method, Extra>::value...)>
+          size_t self = constexpr_sum(std::is_same<is_method, Extra>::value...)>
 constexpr bool expected_num_args(size_t nargs, bool has_args, bool has_kwargs) {
     PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(nargs, has_args, has_kwargs);
     return named == 0 || (self + named + size_t(has_args) + size_t(has_kwargs)) == nargs;
diff --git a/include/pybind11/buffer_info.h b/include/pybind11/buffer_info.h
index eba68d1aa1..ad671654e8 100644
--- a/include/pybind11/buffer_info.h
+++ b/include/pybind11/buffer_info.h
@@ -38,21 +38,28 @@ PYBIND11_NAMESPACE_END(detail)
 
 /// Information record describing a Python buffer object
 struct buffer_info {
-    void *ptr = nullptr;          // Pointer to the underlying storage
-    ssize_t itemsize = 0;         // Size of individual items in bytes
-    ssize_t size = 0;             // Total number of entries
-    std::string format;           // For homogeneous buffers, this should be set to format_descriptor<T>::format()
-    ssize_t ndim = 0;             // Number of dimensions
-    std::vector<ssize_t> shape;   // Shape of the tensor (1 entry per dimension)
-    std::vector<ssize_t> strides; // Number of bytes between adjacent entries (for each per dimension)
-    bool readonly = false;        // flag to indicate if the underlying storage may be written to
+    void *ptr = nullptr;  // Pointer to the underlying storage
+    ssize_t itemsize = 0; // Size of individual items in bytes
+    ssize_t size = 0;     // Total number of entries
+    std::string
+        format; // For homogeneous buffers, this should be set to format_descriptor<T>::format()
+    ssize_t ndim = 0;           // Number of dimensions
+    std::vector<ssize_t> shape; // Shape of the tensor (1 entry per dimension)
+    std::vector<ssize_t>
+        strides;           // Number of bytes between adjacent entries (for each per dimension)
+    bool readonly = false; // flag to indicate if the underlying storage may be written to
 
     buffer_info() = default;
 
-    buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,
-                detail::any_container<ssize_t> shape_in, detail::any_container<ssize_t> strides_in, bool readonly=false)
-    : ptr(ptr), itemsize(itemsize), size(1), format(format), ndim(ndim),
-      shape(std::move(shape_in)), strides(std::move(strides_in)), readonly(readonly) {
+    buffer_info(void *ptr,
+                ssize_t itemsize,
+                const std::string &format,
+                ssize_t ndim,
+                detail::any_container<ssize_t> shape_in,
+                detail::any_container<ssize_t> strides_in,
+                bool readonly = false)
+        : ptr(ptr), itemsize(itemsize), size(1), format(format), ndim(ndim),
+          shape(std::move(shape_in)), strides(std::move(strides_in)), readonly(readonly) {
         if (ndim != (ssize_t) shape.size() || ndim != (ssize_t) strides.size())
             pybind11_fail("buffer_info: ndim doesn't match shape and/or strides length");
         for (size_t i = 0; i < (size_t) ndim; ++i)
@@ -60,36 +67,55 @@ struct buffer_info {
     }
 
     template <typename T>
-    buffer_info(T *ptr, detail::any_container<ssize_t> shape_in, detail::any_container<ssize_t> strides_in, bool readonly=false)
-    : buffer_info(private_ctr_tag(), ptr, sizeof(T), format_descriptor<T>::format(), static_cast<ssize_t>(shape_in->size()), std::move(shape_in), std::move(strides_in), readonly) { }
-
-    buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t size, bool readonly=false)
-    : buffer_info(ptr, itemsize, format, 1, {size}, {itemsize}, readonly) { }
+    buffer_info(T *ptr,
+                detail::any_container<ssize_t> shape_in,
+                detail::any_container<ssize_t> strides_in,
+                bool readonly = false)
+        : buffer_info(private_ctr_tag(),
+                      ptr,
+                      sizeof(T),
+                      format_descriptor<T>::format(),
+                      static_cast<ssize_t>(shape_in->size()),
+                      std::move(shape_in),
+                      std::move(strides_in),
+                      readonly) {}
+
+    buffer_info(void *ptr,
+                ssize_t itemsize,
+                const std::string &format,
+                ssize_t size,
+                bool readonly = false)
+        : buffer_info(ptr, itemsize, format, 1, {size}, {itemsize}, readonly) {}
 
     template <typename T>
-    buffer_info(T *ptr, ssize_t size, bool readonly=false)
-    : buffer_info(ptr, sizeof(T), format_descriptor<T>::format(), size, readonly) { }
+    buffer_info(T *ptr, ssize_t size, bool readonly = false)
+        : buffer_info(ptr, sizeof(T), format_descriptor<T>::format(), size, readonly) {}
 
     template <typename T>
-    buffer_info(const T *ptr, ssize_t size, bool readonly=true)
-    : buffer_info(const_cast<T*>(ptr), sizeof(T), format_descriptor<T>::format(), size, readonly) { }
+    buffer_info(const T *ptr, ssize_t size, bool readonly = true)
+        : buffer_info(
+            const_cast<T *>(ptr), sizeof(T), format_descriptor<T>::format(), size, readonly) {}
 
     explicit buffer_info(Py_buffer *view, bool ownview = true)
-    : buffer_info(view->buf, view->itemsize, view->format, view->ndim,
+        : buffer_info(
+            view->buf,
+            view->itemsize,
+            view->format,
+            view->ndim,
             {view->shape, view->shape + view->ndim},
             /* Though buffer::request() requests PyBUF_STRIDES, ctypes objects
              * ignore this flag and return a view with NULL strides.
              * When strides are NULL, build them manually.  */
             view->strides
-            ? std::vector<ssize_t>(view->strides, view->strides + view->ndim)
-            : detail::c_strides({view->shape, view->shape + view->ndim}, view->itemsize),
+                ? std::vector<ssize_t>(view->strides, view->strides + view->ndim)
+                : detail::c_strides({view->shape, view->shape + view->ndim}, view->itemsize),
             (view->readonly != 0)) {
         this->m_view = view;
         this->ownview = ownview;
     }
 
     buffer_info(const buffer_info &) = delete;
-    buffer_info& operator=(const buffer_info &) = delete;
+    buffer_info &operator=(const buffer_info &) = delete;
 
     buffer_info(buffer_info &&other) noexcept { (*this) = std::move(other); }
 
@@ -108,17 +134,28 @@ struct buffer_info {
     }
 
     ~buffer_info() {
-        if (m_view && ownview) { PyBuffer_Release(m_view); delete m_view; }
+        if (m_view && ownview) {
+            PyBuffer_Release(m_view);
+            delete m_view;
+        }
     }
 
     Py_buffer *view() const { return m_view; }
     Py_buffer *&view() { return m_view; }
-private:
-    struct private_ctr_tag { };
 
-    buffer_info(private_ctr_tag, void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,
-                detail::any_container<ssize_t> &&shape_in, detail::any_container<ssize_t> &&strides_in, bool readonly)
-    : buffer_info(ptr, itemsize, format, ndim, std::move(shape_in), std::move(strides_in), readonly) { }
+private:
+    struct private_ctr_tag {};
+
+    buffer_info(private_ctr_tag,
+                void *ptr,
+                ssize_t itemsize,
+                const std::string &format,
+                ssize_t ndim,
+                detail::any_container<ssize_t> &&shape_in,
+                detail::any_container<ssize_t> &&strides_in,
+                bool readonly)
+        : buffer_info(
+            ptr, itemsize, format, ndim, std::move(shape_in), std::move(strides_in), readonly) {}
 
     Py_buffer *m_view = nullptr;
     bool ownview = false;
@@ -126,17 +163,22 @@ struct buffer_info {
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 
-template <typename T, typename SFINAE = void> struct compare_buffer_info {
-    static bool compare(const buffer_info& b) {
+template <typename T, typename SFINAE = void>
+struct compare_buffer_info {
+    static bool compare(const buffer_info &b) {
         return b.format == format_descriptor<T>::format() && b.itemsize == (ssize_t) sizeof(T);
     }
 };
 
-template <typename T> struct compare_buffer_info<T, detail::enable_if_t<std::is_integral<T>::value>> {
-    static bool compare(const buffer_info& b) {
-        return (size_t) b.itemsize == sizeof(T) && (b.format == format_descriptor<T>::value ||
-            ((sizeof(T) == sizeof(long)) && b.format == (std::is_unsigned<T>::value ? "L" : "l")) ||
-            ((sizeof(T) == sizeof(size_t)) && b.format == (std::is_unsigned<T>::value ? "N" : "n")));
+template <typename T>
+struct compare_buffer_info<T, detail::enable_if_t<std::is_integral<T>::value>> {
+    static bool compare(const buffer_info &b) {
+        return (size_t) b.itemsize == sizeof(T)
+               && (b.format == format_descriptor<T>::value
+                   || ((sizeof(T) == sizeof(long))
+                       && b.format == (std::is_unsigned<T>::value ? "L" : "l"))
+                   || ((sizeof(T) == sizeof(size_t))
+                       && b.format == (std::is_unsigned<T>::value ? "N" : "n")));
     }
 };
 
diff --git a/include/pybind11/cast.h b/include/pybind11/cast.h
index 165102443c..99e99bf153 100644
--- a/include/pybind11/cast.h
+++ b/include/pybind11/cast.h
@@ -10,11 +10,12 @@
 
 #pragma once
 
-#include "pytypes.h"
 #include "detail/common.h"
 #include "detail/descr.h"
 #include "detail/type_caster_base.h"
 #include "detail/typeid.h"
+#include "pytypes.h"
+
 #include <array>
 #include <cstring>
 #include <functional>
@@ -30,41 +31,50 @@
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 PYBIND11_NAMESPACE_BEGIN(detail)
 
-template <typename type, typename SFINAE = void> class type_caster : public type_caster_base<type> { };
-template <typename type> using make_caster = type_caster<intrinsic_t<type>>;
+template <typename type, typename SFINAE = void>
+class type_caster : public type_caster_base<type> {};
+template <typename type>
+using make_caster = type_caster<intrinsic_t<type>>;
 
 // Shortcut for calling a caster's `cast_op_type` cast operator for casting a type_caster to a T
-template <typename T> typename make_caster<T>::template cast_op_type<T> cast_op(make_caster<T> &caster) {
+template <typename T>
+typename make_caster<T>::template cast_op_type<T> cast_op(make_caster<T> &caster) {
     return caster.operator typename make_caster<T>::template cast_op_type<T>();
 }
-template <typename T> typename make_caster<T>::template cast_op_type<typename std::add_rvalue_reference<T>::type>
+template <typename T>
+typename make_caster<T>::template cast_op_type<typename std::add_rvalue_reference<T>::type>
 cast_op(make_caster<T> &&caster) {
-    return std::move(caster).operator
-        typename make_caster<T>::template cast_op_type<typename std::add_rvalue_reference<T>::type>();
+    return std::move(caster).operator typename make_caster<T>::
+        template cast_op_type<typename std::add_rvalue_reference<T>::type>();
 }
 
-template <typename type> class type_caster<std::reference_wrapper<type>> {
+template <typename type>
+class type_caster<std::reference_wrapper<type>> {
 private:
     using caster_t = make_caster<type>;
     caster_t subcaster;
-    using reference_t = type&;
-    using subcaster_cast_op_type =
-        typename caster_t::template cast_op_type<reference_t>;
-
-    static_assert(std::is_same<typename std::remove_const<type>::type &, subcaster_cast_op_type>::value ||
-                  std::is_same<reference_t, subcaster_cast_op_type>::value,
-                  "std::reference_wrapper<T> caster requires T to have a caster with an "
-                  "`operator T &()` or `operator const T &()`");
+    using reference_t = type &;
+    using subcaster_cast_op_type = typename caster_t::template cast_op_type<reference_t>;
+
+    static_assert(
+        std::is_same<typename std::remove_const<type>::type &, subcaster_cast_op_type>::value
+            || std::is_same<reference_t, subcaster_cast_op_type>::value,
+        "std::reference_wrapper<T> caster requires T to have a caster with an "
+        "`operator T &()` or `operator const T &()`");
+
 public:
     bool load(handle src, bool convert) { return subcaster.load(src, convert); }
     static constexpr auto name = caster_t::name;
-    static handle cast(const std::reference_wrapper<type> &src, return_value_policy policy, handle parent) {
+    static handle
+    cast(const std::reference_wrapper<type> &src, return_value_policy policy, handle parent) {
         // It is definitely wrong to take ownership of this pointer, so mask that rvp
-        if (policy == return_value_policy::take_ownership || policy == return_value_policy::automatic)
+        if (policy == return_value_policy::take_ownership
+            || policy == return_value_policy::automatic)
             policy = return_value_policy::automatic_reference;
         return caster_t::cast(&src.get(), policy, parent);
     }
-    template <typename T> using cast_op_type = std::reference_wrapper<type>;
+    template <typename T>
+    using cast_op_type = std::reference_wrapper<type>;
     explicit operator std::reference_wrapper<type>() { return cast_op<type &>(subcaster); }
 };
 
@@ -91,24 +101,25 @@ public:
     template <typename T_>                                                                        \
     using cast_op_type = pybind11::detail::movable_cast_op_type<T_>
 
-template <typename CharT> using is_std_char_type = any_of<
-    std::is_same<CharT, char>, /* std::string */
+template <typename CharT>
+using is_std_char_type = any_of<std::is_same<CharT, char>, /* std::string */
 #if defined(PYBIND11_HAS_U8STRING)
-    std::is_same<CharT, char8_t>, /* std::u8string */
+                                std::is_same<CharT, char8_t>, /* std::u8string */
 #endif
-    std::is_same<CharT, char16_t>, /* std::u16string */
-    std::is_same<CharT, char32_t>, /* std::u32string */
-    std::is_same<CharT, wchar_t> /* std::wstring */
->;
-
+                                std::is_same<CharT, char16_t>, /* std::u16string */
+                                std::is_same<CharT, char32_t>, /* std::u32string */
+                                std::is_same<CharT, wchar_t>   /* std::wstring */
+                                >;
 
 template <typename T>
 struct type_caster<T, enable_if_t<std::is_arithmetic<T>::value && !is_std_char_type<T>::value>> {
     using _py_type_0 = conditional_t<sizeof(T) <= sizeof(long), long, long long>;
-    using _py_type_1 = conditional_t<std::is_signed<T>::value, _py_type_0, typename std::make_unsigned<_py_type_0>::type>;
+    using _py_type_1 = conditional_t<std::is_signed<T>::value,
+                                     _py_type_0,
+                                     typename std::make_unsigned<_py_type_0>::type>;
     using py_type = conditional_t<std::is_floating_point<T>::value, double, _py_type_1>;
-public:
 
+public:
     bool load(handle src, bool convert) {
         py_type py_value;
 
@@ -136,14 +147,13 @@ struct type_caster<T, enable_if_t<std::is_arithmetic<T>::value && !is_std_char_t
             // PyPy: 7.3.7's 3.8 does not implement PyLong_*'s __index__ calls.
 #if PY_VERSION_HEX < 0x03080000 || defined(PYPY_VERSION)
             object index;
-            if (!PYBIND11_LONG_CHECK(src.ptr())) {  // So: index_check(src.ptr())
+            if (!PYBIND11_LONG_CHECK(src.ptr())) { // So: index_check(src.ptr())
                 index = reinterpret_steal<object>(PyNumber_Index(src.ptr()));
                 if (!index) {
                     PyErr_Clear();
                     if (!convert)
                         return false;
-                }
-                else {
+                } else {
                     src_or_index = index;
                 }
             }
@@ -152,8 +162,8 @@ struct type_caster<T, enable_if_t<std::is_arithmetic<T>::value && !is_std_char_t
                 py_value = as_unsigned<py_type>(src_or_index.ptr());
             } else { // signed integer:
                 py_value = sizeof(T) <= sizeof(long)
-                    ? (py_type) PyLong_AsLong(src_or_index.ptr())
-                    : (py_type) PYBIND11_LONG_AS_LONGLONG(src_or_index.ptr());
+                               ? (py_type) PyLong_AsLong(src_or_index.ptr())
+                               : (py_type) PYBIND11_LONG_AS_LONGLONG(src_or_index.ptr());
             }
         }
 
@@ -162,12 +172,14 @@ struct type_caster<T, enable_if_t<std::is_arithmetic<T>::value && !is_std_char_t
 
         // Check to see if the conversion is valid (integers should match exactly)
         // Signed/unsigned checks happen elsewhere
-        if (py_err || (std::is_integral<T>::value && sizeof(py_type) != sizeof(T) && py_value != (py_type) (T) py_value)) {
+        if (py_err
+            || (std::is_integral<T>::value && sizeof(py_type) != sizeof(T)
+                && py_value != (py_type) (T) py_value)) {
             PyErr_Clear();
             if (py_err && convert && (PyNumber_Check(src.ptr()) != 0)) {
                 auto tmp = reinterpret_steal<object>(std::is_floating_point<T>::value
-                                                     ? PyNumber_Float(src.ptr())
-                                                     : PyNumber_Long(src.ptr()));
+                                                         ? PyNumber_Float(src.ptr())
+                                                         : PyNumber_Long(src.ptr()));
                 PyErr_Clear();
                 return load(tmp, false);
             }
@@ -178,32 +190,40 @@ struct type_caster<T, enable_if_t<std::is_arithmetic<T>::value && !is_std_char_t
         return true;
     }
 
-    template<typename U = T>
+    template <typename U = T>
     static typename std::enable_if<std::is_floating_point<U>::value, handle>::type
     cast(U src, return_value_policy /* policy */, handle /* parent */) {
         return PyFloat_FromDouble((double) src);
     }
 
-    template<typename U = T>
-    static typename std::enable_if<!std::is_floating_point<U>::value && std::is_signed<U>::value && (sizeof(U) <= sizeof(long)), handle>::type
+    template <typename U = T>
+    static typename std::enable_if<!std::is_floating_point<U>::value && std::is_signed<U>::value
+                                       && (sizeof(U) <= sizeof(long)),
+                                   handle>::type
     cast(U src, return_value_policy /* policy */, handle /* parent */) {
         return PYBIND11_LONG_FROM_SIGNED((long) src);
     }
 
-    template<typename U = T>
-    static typename std::enable_if<!std::is_floating_point<U>::value && std::is_unsigned<U>::value && (sizeof(U) <= sizeof(unsigned long)), handle>::type
+    template <typename U = T>
+    static typename std::enable_if<!std::is_floating_point<U>::value && std::is_unsigned<U>::value
+                                       && (sizeof(U) <= sizeof(unsigned long)),
+                                   handle>::type
     cast(U src, return_value_policy /* policy */, handle /* parent */) {
         return PYBIND11_LONG_FROM_UNSIGNED((unsigned long) src);
     }
 
-    template<typename U = T>
-    static typename std::enable_if<!std::is_floating_point<U>::value && std::is_signed<U>::value && (sizeof(U) > sizeof(long)), handle>::type
+    template <typename U = T>
+    static typename std::enable_if<!std::is_floating_point<U>::value && std::is_signed<U>::value
+                                       && (sizeof(U) > sizeof(long)),
+                                   handle>::type
     cast(U src, return_value_policy /* policy */, handle /* parent */) {
         return PyLong_FromLongLong((long long) src);
     }
 
-    template<typename U = T>
-    static typename std::enable_if<!std::is_floating_point<U>::value && std::is_unsigned<U>::value && (sizeof(U) > sizeof(unsigned long)), handle>::type
+    template <typename U = T>
+    static typename std::enable_if<!std::is_floating_point<U>::value && std::is_unsigned<U>::value
+                                       && (sizeof(U) > sizeof(unsigned long)),
+                                   handle>::type
     cast(U src, return_value_policy /* policy */, handle /* parent */) {
         return PyLong_FromUnsignedLongLong((unsigned long long) src);
     }
@@ -211,7 +231,8 @@ struct type_caster<T, enable_if_t<std::is_arithmetic<T>::value && !is_std_char_t
     PYBIND11_TYPE_CASTER(T, const_name<std::is_integral<T>::value>("int", "float"));
 };
 
-template<typename T> struct void_caster {
+template <typename T>
+struct void_caster {
 public:
     bool load(handle src, bool) {
         if (src && src.is_none())
@@ -224,9 +245,11 @@ template<typename T> struct void_caster {
     PYBIND11_TYPE_CASTER(T, const_name("None"));
 };
 
-template <> class type_caster<void_type> : public void_caster<void_type> {};
+template <>
+class type_caster<void_type> : public void_caster<void_type> {};
 
-template <> class type_caster<void> : public type_caster<void_type> {
+template <>
+class type_caster<void> : public type_caster<void_type> {
 public:
     using type_caster<void_type>::cast;
 
@@ -246,7 +269,7 @@ template <> class type_caster<void> : public type_caster<void_type> {
         }
 
         /* Check if this is a C++ type */
-        auto &bases = all_type_info((PyTypeObject *) type::handle_of(h).ptr());
+        const auto &bases = all_type_info((PyTypeObject *) type::handle_of(h).ptr());
         if (bases.size() == 1) { // Only allowing loading from a single-value type
             value = values_and_holders(reinterpret_cast<instance *>(h.ptr())).begin()->value_ptr();
             return true;
@@ -262,19 +285,24 @@ template <> class type_caster<void> : public type_caster<void_type> {
         return none().inc_ref();
     }
 
-    template <typename T> using cast_op_type = void*&;
+    template <typename T>
+    using cast_op_type = void *&;
     explicit operator void *&() { return value; }
     static constexpr auto name = const_name("capsule");
+
 private:
     void *value = nullptr;
 };
 
-template <> class type_caster<std::nullptr_t> : public void_caster<std::nullptr_t> { };
+template <>
+class type_caster<std::nullptr_t> : public void_caster<std::nullptr_t> {};
 
-template <> class type_caster<bool> {
+template <>
+class type_caster<bool> {
 public:
     bool load(handle src, bool convert) {
-        if (!src) return false;
+        if (!src)
+            return false;
         if (src.ptr() == Py_True) {
             value = true;
             return true;
@@ -288,22 +316,22 @@ template <> class type_caster<bool> {
 
             Py_ssize_t res = -1;
             if (src.is_none()) {
-                res = 0;  // None is implicitly converted to False
+                res = 0; // None is implicitly converted to False
             }
-            #if defined(PYPY_VERSION)
+#if defined(PYPY_VERSION)
             // On PyPy, check that "__bool__" (or "__nonzero__" on Python 2.7) attr exists
             else if (hasattr(src, PYBIND11_BOOL_ATTR)) {
                 res = PyObject_IsTrue(src.ptr());
             }
-            #else
+#else
             // Alternate approach for CPython: this does the same as the above, but optimized
             // using the CPython API so as to avoid an unneeded attribute lookup.
-            else if (auto tp_as_number = src.ptr()->ob_type->tp_as_number) {
+            else if (auto *tp_as_number = src.ptr()->ob_type->tp_as_number) {
                 if (PYBIND11_NB_BOOL(tp_as_number)) {
                     res = (*PYBIND11_NB_BOOL(tp_as_number))(src.ptr());
                 }
             }
-            #endif
+#endif
             if (res == 0 || res == 1) {
                 value = (res != 0);
                 return true;
@@ -319,20 +347,25 @@ template <> class type_caster<bool> {
 };
 
 // Helper class for UTF-{8,16,32} C++ stl strings:
-template <typename StringType, bool IsView = false> struct string_caster {
+template <typename StringType, bool IsView = false>
+struct string_caster {
     using CharT = typename StringType::value_type;
 
     // Simplify life by being able to assume standard char sizes (the standard only guarantees
     // minimums, but Python requires exact sizes)
-    static_assert(!std::is_same<CharT, char>::value || sizeof(CharT) == 1, "Unsupported char size != 1");
+    static_assert(!std::is_same<CharT, char>::value || sizeof(CharT) == 1,
+                  "Unsupported char size != 1");
 #if defined(PYBIND11_HAS_U8STRING)
-    static_assert(!std::is_same<CharT, char8_t>::value || sizeof(CharT) == 1, "Unsupported char8_t size != 1");
+    static_assert(!std::is_same<CharT, char8_t>::value || sizeof(CharT) == 1,
+                  "Unsupported char8_t size != 1");
 #endif
-    static_assert(!std::is_same<CharT, char16_t>::value || sizeof(CharT) == 2, "Unsupported char16_t size != 2");
-    static_assert(!std::is_same<CharT, char32_t>::value || sizeof(CharT) == 4, "Unsupported char32_t size != 4");
+    static_assert(!std::is_same<CharT, char16_t>::value || sizeof(CharT) == 2,
+                  "Unsupported char16_t size != 2");
+    static_assert(!std::is_same<CharT, char32_t>::value || sizeof(CharT) == 4,
+                  "Unsupported char32_t size != 4");
     // wchar_t can be either 16 bits (Windows) or 32 (everywhere else)
     static_assert(!std::is_same<CharT, wchar_t>::value || sizeof(CharT) == 2 || sizeof(CharT) == 4,
-            "Unsupported wchar_t size != 2/4");
+                  "Unsupported wchar_t size != 2/4");
     static constexpr size_t UTF_N = 8 * sizeof(CharT);
 
     bool load(handle src, bool) {
@@ -356,7 +389,10 @@ template <typename StringType, bool IsView = false> struct string_caster {
                 return false;
 
             temp = reinterpret_steal<object>(PyUnicode_FromObject(load_src.ptr()));
-            if (!temp) { PyErr_Clear(); return false; }
+            if (!temp) {
+                PyErr_Clear();
+                return false;
+            }
             load_src = temp;
 #endif
         }
@@ -377,11 +413,19 @@ template <typename StringType, bool IsView = false> struct string_caster {
         }
 #endif
 
-        auto utfNbytes = reinterpret_steal<object>(PyUnicode_AsEncodedString(
-            load_src.ptr(), UTF_N == 8 ? "utf-8" : UTF_N == 16 ? "utf-16" : "utf-32", nullptr));
-        if (!utfNbytes) { PyErr_Clear(); return false; }
+        auto utfNbytes
+            = reinterpret_steal<object>(PyUnicode_AsEncodedString(load_src.ptr(),
+                                                                  UTF_N == 8    ? "utf-8"
+                                                                  : UTF_N == 16 ? "utf-16"
+                                                                                : "utf-32",
+                                                                  nullptr));
+        if (!utfNbytes) {
+            PyErr_Clear();
+            return false;
+        }
 
-        const auto *buffer = reinterpret_cast<const CharT *>(PYBIND11_BYTES_AS_STRING(utfNbytes.ptr()));
+        const auto *buffer
+            = reinterpret_cast<const CharT *>(PYBIND11_BYTES_AS_STRING(utfNbytes.ptr()));
         size_t length = (size_t) PYBIND11_BYTES_SIZE(utfNbytes.ptr()) / sizeof(CharT);
         // Skip BOM for UTF-16/32
         if (PYBIND11_SILENCE_MSVC_C4127(UTF_N > 8)) {
@@ -397,11 +441,13 @@ template <typename StringType, bool IsView = false> struct string_caster {
         return true;
     }
 
-    static handle cast(const StringType &src, return_value_policy /* policy */, handle /* parent */) {
+    static handle
+    cast(const StringType &src, return_value_policy /* policy */, handle /* parent */) {
         const char *buffer = reinterpret_cast<const char *>(src.data());
         auto nbytes = ssize_t(src.size() * sizeof(CharT));
         handle s = decode_utfN(buffer, nbytes);
-        if (!s) throw error_already_set();
+        if (!s)
+            throw error_already_set();
         return s;
     }
 
@@ -410,14 +456,19 @@ template <typename StringType, bool IsView = false> struct string_caster {
 private:
     static handle decode_utfN(const char *buffer, ssize_t nbytes) {
 #if !defined(PYPY_VERSION)
-        return
-            UTF_N == 8  ? PyUnicode_DecodeUTF8(buffer, nbytes, nullptr) :
-            UTF_N == 16 ? PyUnicode_DecodeUTF16(buffer, nbytes, nullptr, nullptr) :
-                          PyUnicode_DecodeUTF32(buffer, nbytes, nullptr, nullptr);
+        return UTF_N == 8    ? PyUnicode_DecodeUTF8(buffer, nbytes, nullptr)
+               : UTF_N == 16 ? PyUnicode_DecodeUTF16(buffer, nbytes, nullptr, nullptr)
+                             : PyUnicode_DecodeUTF32(buffer, nbytes, nullptr, nullptr);
 #else
-        // PyPy segfaults when on PyUnicode_DecodeUTF16 (and possibly on PyUnicode_DecodeUTF32 as well),
-        // so bypass the whole thing by just passing the encoding as a string value, which works properly:
-        return PyUnicode_Decode(buffer, nbytes, UTF_N == 8 ? "utf-8" : UTF_N == 16 ? "utf-16" : "utf-32", nullptr);
+        // PyPy segfaults when on PyUnicode_DecodeUTF16 (and possibly on PyUnicode_DecodeUTF32 as
+        // well), so bypass the whole thing by just passing the encoding as a string value, which
+        // works properly:
+        return PyUnicode_Decode(buffer,
+                                nbytes,
+                                UTF_N == 8    ? "utf-8"
+                                : UTF_N == 16 ? "utf-16"
+                                              : "utf-32",
+                                nullptr);
 #endif
     }
 
@@ -440,33 +491,41 @@ template <typename StringType, bool IsView = false> struct string_caster {
     }
 
     template <typename C = CharT>
-    bool load_bytes(enable_if_t<!std::is_same<C, char>::value, handle>) { return false; }
+    bool load_bytes(enable_if_t<!std::is_same<C, char>::value, handle>) {
+        return false;
+    }
 };
 
 template <typename CharT, class Traits, class Allocator>
-struct type_caster<std::basic_string<CharT, Traits, Allocator>, enable_if_t<is_std_char_type<CharT>::value>>
+struct type_caster<std::basic_string<CharT, Traits, Allocator>,
+                   enable_if_t<is_std_char_type<CharT>::value>>
     : string_caster<std::basic_string<CharT, Traits, Allocator>> {};
 
 #ifdef PYBIND11_HAS_STRING_VIEW
 template <typename CharT, class Traits>
-struct type_caster<std::basic_string_view<CharT, Traits>, enable_if_t<is_std_char_type<CharT>::value>>
+struct type_caster<std::basic_string_view<CharT, Traits>,
+                   enable_if_t<is_std_char_type<CharT>::value>>
     : string_caster<std::basic_string_view<CharT, Traits>, true> {};
 #endif
 
 // Type caster for C-style strings.  We basically use a std::string type caster, but also add the
 // ability to use None as a nullptr char* (which the string caster doesn't allow).
-template <typename CharT> struct type_caster<CharT, enable_if_t<is_std_char_type<CharT>::value>> {
+template <typename CharT>
+struct type_caster<CharT, enable_if_t<is_std_char_type<CharT>::value>> {
     using StringType = std::basic_string<CharT>;
     using StringCaster = type_caster<StringType>;
     StringCaster str_caster;
     bool none = false;
     CharT one_char = 0;
+
 public:
     bool load(handle src, bool convert) {
-        if (!src) return false;
+        if (!src)
+            return false;
         if (src.is_none()) {
             // Defer accepting None to other overloads (if we aren't in convert mode):
-            if (!convert) return false;
+            if (!convert)
+                return false;
             none = true;
             return true;
         }
@@ -474,14 +533,16 @@ template <typename CharT> struct type_caster<CharT, enable_if_t<is_std_char_type
     }
 
     static handle cast(const CharT *src, return_value_policy policy, handle parent) {
-        if (src == nullptr) return pybind11::none().inc_ref();
+        if (src == nullptr)
+            return pybind11::none().inc_ref();
         return StringCaster::cast(StringType(src), policy, parent);
     }
 
     static handle cast(CharT src, return_value_policy policy, handle parent) {
         if (std::is_same<char, CharT>::value) {
             handle s = PyUnicode_DecodeLatin1((const char *) &src, 1, nullptr);
-            if (!s) throw error_already_set();
+            if (!s)
+                throw error_already_set();
             return s;
         }
         return StringCaster::cast(StringType(1, src), policy, parent);
@@ -500,10 +561,10 @@ template <typename CharT> struct type_caster<CharT, enable_if_t<is_std_char_type
             throw value_error("Cannot convert empty string to a character");
 
         // If we're in UTF-8 mode, we have two possible failures: one for a unicode character that
-        // is too high, and one for multiple unicode characters (caught later), so we need to figure
-        // out how long the first encoded character is in bytes to distinguish between these two
-        // errors.  We also allow want to allow unicode characters U+0080 through U+00FF, as those
-        // can fit into a single char value.
+        // is too high, and one for multiple unicode characters (caught later), so we need to
+        // figure out how long the first encoded character is in bytes to distinguish between these
+        // two errors.  We also allow want to allow unicode characters U+0080 through U+00FF, as
+        // those can fit into a single char value.
         if (PYBIND11_SILENCE_MSVC_C4127(StringCaster::UTF_N == 8) && str_len > 1 && str_len <= 4) {
             auto v0 = static_cast<unsigned char>(value[0]);
             // low bits only: 0-127
@@ -518,7 +579,8 @@ template <typename CharT> struct type_caster<CharT, enable_if_t<is_std_char_type
             if (char0_bytes == str_len) {
                 // If we have a 128-255 value, we can decode it into a single char:
                 if (char0_bytes == 2 && (v0 & 0xFC) == 0xC0) { // 0x110000xx 0x10xxxxxx
-                    one_char = static_cast<CharT>(((v0 & 3) << 6) + (static_cast<unsigned char>(value[1]) & 0x3F));
+                    one_char = static_cast<CharT>(((v0 & 3) << 6)
+                                                  + (static_cast<unsigned char>(value[1]) & 0x3F));
                     return one_char;
                 }
                 // Otherwise we have a single character, but it's > U+00FF
@@ -543,16 +605,18 @@ template <typename CharT> struct type_caster<CharT, enable_if_t<is_std_char_type
     }
 
     static constexpr auto name = const_name(PYBIND11_STRING_NAME);
-    template <typename _T> using cast_op_type = pybind11::detail::cast_op_type<_T>;
+    template <typename _T>
+    using cast_op_type = pybind11::detail::cast_op_type<_T>;
 };
 
 // Base implementation for std::tuple and std::pair
-template <template<typename...> class Tuple, typename... Ts> class tuple_caster {
+template <template <typename...> class Tuple, typename... Ts>
+class tuple_caster {
     using type = Tuple<Ts...>;
     static constexpr auto size = sizeof...(Ts);
     using indices = make_index_sequence<size>;
-public:
 
+public:
     bool load(handle src, bool convert) {
         if (!isinstance<sequence>(src))
             return false;
@@ -570,7 +634,8 @@ template <template<typename...> class Tuple, typename... Ts> class tuple_caster
     // copied from the PYBIND11_TYPE_CASTER macro
     template <typename T>
     static handle cast(T *src, return_value_policy policy, handle parent) {
-        if (!src) return none().release();
+        if (!src)
+            return none().release();
         if (policy == return_value_policy::take_ownership) {
             auto h = cast(std::move(*src), policy, parent);
             delete src;
@@ -579,18 +644,24 @@ template <template<typename...> class Tuple, typename... Ts> class tuple_caster
         return cast(*src, policy, parent);
     }
 
-    static constexpr auto name = const_name("Tuple[") + concat(make_caster<Ts>::name...) + const_name("]");
+    static constexpr auto name
+        = const_name("Tuple[") + concat(make_caster<Ts>::name...) + const_name("]");
 
-    template <typename T> using cast_op_type = type;
+    template <typename T>
+    using cast_op_type = type;
 
     explicit operator type() & { return implicit_cast(indices{}); }
     explicit operator type() && { return std::move(*this).implicit_cast(indices{}); }
 
 protected:
     template <size_t... Is>
-    type implicit_cast(index_sequence<Is...>) & { return type(cast_op<Ts>(std::get<Is>(subcasters))...); }
+    type implicit_cast(index_sequence<Is...>) & {
+        return type(cast_op<Ts>(std::get<Is>(subcasters))...);
+    }
     template <size_t... Is>
-    type implicit_cast(index_sequence<Is...>) && { return type(cast_op<Ts>(std::move(std::get<Is>(subcasters)))...); }
+    type implicit_cast(index_sequence<Is...>) && {
+        return type(cast_op<Ts>(std::move(std::get<Is>(subcasters)))...);
+    }
 
     static constexpr bool load_impl(const sequence &, bool, index_sequence<>) { return true; }
 
@@ -609,18 +680,18 @@ template <template<typename...> class Tuple, typename... Ts> class tuple_caster
 
     /* Implementation: Convert a C++ tuple into a Python tuple */
     template <typename T, size_t... Is>
-    static handle cast_impl(T &&src, return_value_policy policy, handle parent, index_sequence<Is...>) {
+    static handle
+    cast_impl(T &&src, return_value_policy policy, handle parent, index_sequence<Is...>) {
         PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(src, policy, parent);
         PYBIND11_WORKAROUND_INCORRECT_GCC_UNUSED_BUT_SET_PARAMETER(policy, parent);
-        std::array<object, size> entries{{
-            reinterpret_steal<object>(make_caster<Ts>::cast(std::get<Is>(std::forward<T>(src)), policy, parent))...
-        }};
-        for (const auto &entry: entries)
+        std::array<object, size> entries{{reinterpret_steal<object>(
+            make_caster<Ts>::cast(std::get<Is>(std::forward<T>(src)), policy, parent))...}};
+        for (const auto &entry : entries)
             if (!entry)
                 return handle();
         tuple result(size);
         int counter = 0;
-        for (auto & entry: entries)
+        for (auto &entry : entries)
             PyTuple_SET_ITEM(result.ptr(), counter++, entry.release().ptr());
         return result.release();
     }
@@ -628,11 +699,11 @@ template <template<typename...> class Tuple, typename... Ts> class tuple_caster
     Tuple<make_caster<Ts>...> subcasters;
 };
 
-template <typename T1, typename T2> class type_caster<std::pair<T1, T2>>
-    : public tuple_caster<std::pair, T1, T2> {};
+template <typename T1, typename T2>
+class type_caster<std::pair<T1, T2>> : public tuple_caster<std::pair, T1, T2> {};
 
-template <typename... Ts> class type_caster<std::tuple<Ts...>>
-    : public tuple_caster<std::tuple, Ts...> {};
+template <typename... Ts>
+class type_caster<std::tuple<Ts...>> : public tuple_caster<std::tuple, Ts...> {};
 
 /// Helper class which abstracts away certain actions. Users can provide specializations for
 /// custom holders, but it's only necessary if the type has a non-standard interface.
@@ -651,7 +722,7 @@ struct copyable_holder_caster : public type_caster_base<type> {
 public:
     using base = type_caster_base<type>;
     static_assert(std::is_base_of<base, type_caster<type>>::value,
-            "Holder classes are only supported for custom types");
+                  "Holder classes are only supported for custom types");
     using base::base;
     using base::cast;
     using base::typeinfo;
@@ -661,12 +732,12 @@ struct copyable_holder_caster : public type_caster_base<type> {
         return base::template load_impl<copyable_holder_caster<type, holder_type>>(src, convert);
     }
 
-    explicit operator type*() { return this->value; }
+    explicit operator type *() { return this->value; }
     // static_cast works around compiler error with MSVC 17 and CUDA 10.2
     // see issue #2180
-    explicit operator type&() { return *(static_cast<type *>(this->value)); }
-    explicit operator holder_type*() { return std::addressof(holder); }
-    explicit operator holder_type&() { return holder; }
+    explicit operator type &() { return *(static_cast<type *>(this->value)); }
+    explicit operator holder_type *() { return std::addressof(holder); }
+    explicit operator holder_type &() { return holder; }
 
     static handle cast(const holder_type &src, return_value_policy, handle) {
         const auto *ptr = holder_helper<holder_type>::get(src);
@@ -695,10 +766,14 @@ struct copyable_holder_caster : public type_caster_base<type> {
 #endif
     }
 
-    template <typename T = holder_type, detail::enable_if_t<!std::is_constructible<T, const T &, type*>::value, int> = 0>
-    bool try_implicit_casts(handle, bool) { return false; }
+    template <typename T = holder_type,
+              detail::enable_if_t<!std::is_constructible<T, const T &, type *>::value, int> = 0>
+    bool try_implicit_casts(handle, bool) {
+        return false;
+    }
 
-    template <typename T = holder_type, detail::enable_if_t<std::is_constructible<T, const T &, type*>::value, int> = 0>
+    template <typename T = holder_type,
+              detail::enable_if_t<std::is_constructible<T, const T &, type *>::value, int> = 0>
     bool try_implicit_casts(handle src, bool convert) {
         for (auto &cast : typeinfo->implicit_casts) {
             copyable_holder_caster sub_caster(*cast.first);
@@ -713,13 +788,12 @@ struct copyable_holder_caster : public type_caster_base<type> {
 
     static bool try_direct_conversions(handle) { return false; }
 
-
     holder_type holder;
 };
 
 /// Specialize for the common std::shared_ptr, so users don't need to
 template <typename T>
-class type_caster<std::shared_ptr<T>> : public copyable_holder_caster<T, std::shared_ptr<T>> { };
+class type_caster<std::shared_ptr<T>> : public copyable_holder_caster<T, std::shared_ptr<T>> {};
 
 /// Type caster for holder types like std::unique_ptr.
 /// Please consider the SFINAE hook an implementation detail, as explained
@@ -727,7 +801,7 @@ class type_caster<std::shared_ptr<T>> : public copyable_holder_caster<T, std::sh
 template <typename type, typename holder_type, typename SFINAE = void>
 struct move_only_holder_caster {
     static_assert(std::is_base_of<type_caster_base<type>, type_caster<type>>::value,
-            "Holder classes are only supported for custom types");
+                  "Holder classes are only supported for custom types");
 
     static handle cast(holder_type &&src, return_value_policy, handle) {
         auto *ptr = holder_helper<holder_type>::get(src);
@@ -738,47 +812,87 @@ struct move_only_holder_caster {
 
 template <typename type, typename deleter>
 class type_caster<std::unique_ptr<type, deleter>>
-    : public move_only_holder_caster<type, std::unique_ptr<type, deleter>> { };
+    : public move_only_holder_caster<type, std::unique_ptr<type, deleter>> {};
 
 template <typename type, typename holder_type>
 using type_caster_holder = conditional_t<is_copy_constructible<holder_type>::value,
                                          copyable_holder_caster<type, holder_type>,
                                          move_only_holder_caster<type, holder_type>>;
 
-template <typename T, bool Value = false> struct always_construct_holder { static constexpr bool value = Value; };
+template <typename T, bool Value = false>
+struct always_construct_holder {
+    static constexpr bool value = Value;
+};
 
 /// Create a specialization for custom holder types (silently ignores std::shared_ptr)
-#define PYBIND11_DECLARE_HOLDER_TYPE(type, holder_type, ...) \
-    namespace pybind11 { namespace detail { \
-    template <typename type> \
-    struct always_construct_holder<holder_type> : always_construct_holder<void, ##__VA_ARGS__>  { }; \
-    template <typename type> \
-    class type_caster<holder_type, enable_if_t<!is_shared_ptr<holder_type>::value>> \
-        : public type_caster_holder<type, holder_type> { }; \
-    }}
+#define PYBIND11_DECLARE_HOLDER_TYPE(type, holder_type, ...)                                      \
+    namespace pybind11 {                                                                          \
+    namespace detail {                                                                            \
+    template <typename type>                                                                      \
+    struct always_construct_holder<holder_type> : always_construct_holder<void, ##__VA_ARGS__> {  \
+    };                                                                                            \
+    template <typename type>                                                                      \
+    class type_caster<holder_type, enable_if_t<!is_shared_ptr<holder_type>::value>>               \
+        : public type_caster_holder<type, holder_type> {};                                        \
+    }                                                                                             \
+    }
 
 // PYBIND11_DECLARE_HOLDER_TYPE holder types:
-template <typename base, typename holder> struct is_holder_type :
-    std::is_base_of<detail::type_caster_holder<base, holder>, detail::type_caster<holder>> {};
+template <typename base, typename holder>
+struct is_holder_type
+    : std::is_base_of<detail::type_caster_holder<base, holder>, detail::type_caster<holder>> {};
 // Specialization for always-supported unique_ptr holders:
-template <typename base, typename deleter> struct is_holder_type<base, std::unique_ptr<base, deleter>> :
-    std::true_type {};
-
-template <typename T> struct handle_type_name { static constexpr auto name = const_name<T>(); };
-template <> struct handle_type_name<bool_> { static constexpr auto name = const_name("bool"); };
-template <> struct handle_type_name<bytes> { static constexpr auto name = const_name(PYBIND11_BYTES_NAME); };
-template <> struct handle_type_name<int_> { static constexpr auto name = const_name("int"); };
-template <> struct handle_type_name<iterable> { static constexpr auto name = const_name("Iterable"); };
-template <> struct handle_type_name<iterator> { static constexpr auto name = const_name("Iterator"); };
-template <> struct handle_type_name<float_> { static constexpr auto name = const_name("float"); };
-template <> struct handle_type_name<none> { static constexpr auto name = const_name("None"); };
-template <> struct handle_type_name<args> { static constexpr auto name = const_name("*args"); };
-template <> struct handle_type_name<kwargs> { static constexpr auto name = const_name("**kwargs"); };
+template <typename base, typename deleter>
+struct is_holder_type<base, std::unique_ptr<base, deleter>> : std::true_type {};
+
+template <typename T>
+struct handle_type_name {
+    static constexpr auto name = const_name<T>();
+};
+template <>
+struct handle_type_name<bool_> {
+    static constexpr auto name = const_name("bool");
+};
+template <>
+struct handle_type_name<bytes> {
+    static constexpr auto name = const_name(PYBIND11_BYTES_NAME);
+};
+template <>
+struct handle_type_name<int_> {
+    static constexpr auto name = const_name("int");
+};
+template <>
+struct handle_type_name<iterable> {
+    static constexpr auto name = const_name("Iterable");
+};
+template <>
+struct handle_type_name<iterator> {
+    static constexpr auto name = const_name("Iterator");
+};
+template <>
+struct handle_type_name<float_> {
+    static constexpr auto name = const_name("float");
+};
+template <>
+struct handle_type_name<none> {
+    static constexpr auto name = const_name("None");
+};
+template <>
+struct handle_type_name<args> {
+    static constexpr auto name = const_name("*args");
+};
+template <>
+struct handle_type_name<kwargs> {
+    static constexpr auto name = const_name("**kwargs");
+};
 
 template <typename type>
 struct pyobject_caster {
     template <typename T = type, enable_if_t<std::is_same<T, handle>::value, int> = 0>
-    bool load(handle src, bool /* convert */) { value = src; return static_cast<bool>(value); }
+    bool load(handle src, bool /* convert */) {
+        value = src;
+        return static_cast<bool>(value);
+    }
 
     template <typename T = type, enable_if_t<std::is_base_of<object, T>::value, int> = 0>
     bool load(handle src, bool /* convert */) {
@@ -788,7 +902,8 @@ struct pyobject_caster {
         // un-cluttered later after Python 2 support is dropped.
         if (PYBIND11_SILENCE_MSVC_C4127(std::is_same<T, str>::value) && isinstance<bytes>(src)) {
             PyObject *str_from_bytes = PyUnicode_FromEncodedObject(src.ptr(), "utf-8", nullptr);
-            if (!str_from_bytes) throw error_already_set();
+            if (!str_from_bytes)
+                throw error_already_set();
             value = reinterpret_steal<type>(str_from_bytes);
             return true;
         }
@@ -806,7 +921,7 @@ struct pyobject_caster {
 };
 
 template <typename T>
-class type_caster<T, enable_if_t<is_pyobject<T>::value>> : public pyobject_caster<T> { };
+class type_caster<T, enable_if_t<is_pyobject<T>::value>> : public pyobject_caster<T> {};
 
 // Our conditions for enabling moving are quite restrictive:
 // At compile time:
@@ -817,65 +932,81 @@ class type_caster<T, enable_if_t<is_pyobject<T>::value>> : public pyobject_caste
 // - if the type is non-copy-constructible, the object must be the sole owner of the type (i.e. it
 //   must have ref_count() == 1)h
 // If any of the above are not satisfied, we fall back to copying.
-template <typename T> using move_is_plain_type = satisfies_none_of<T,
-    std::is_void, std::is_pointer, std::is_reference, std::is_const
->;
-template <typename T, typename SFINAE = void> struct move_always : std::false_type {};
-template <typename T> struct move_always<T, enable_if_t<all_of<
-    move_is_plain_type<T>,
-    negation<is_copy_constructible<T>>,
-    std::is_move_constructible<T>,
-    std::is_same<decltype(std::declval<make_caster<T>>().operator T&()), T&>
->::value>> : std::true_type {};
-template <typename T, typename SFINAE = void> struct move_if_unreferenced : std::false_type {};
-template <typename T> struct move_if_unreferenced<T, enable_if_t<all_of<
-    move_is_plain_type<T>,
-    negation<move_always<T>>,
-    std::is_move_constructible<T>,
-    std::is_same<decltype(std::declval<make_caster<T>>().operator T&()), T&>
->::value>> : std::true_type {};
-template <typename T> using move_never = none_of<move_always<T>, move_if_unreferenced<T>>;
+template <typename T>
+using move_is_plain_type
+    = satisfies_none_of<T, std::is_void, std::is_pointer, std::is_reference, std::is_const>;
+template <typename T, typename SFINAE = void>
+struct move_always : std::false_type {};
+template <typename T>
+struct move_always<
+    T,
+    enable_if_t<
+        all_of<move_is_plain_type<T>,
+               negation<is_copy_constructible<T>>,
+               std::is_move_constructible<T>,
+               std::is_same<decltype(std::declval<make_caster<T>>().operator T &()), T &>>::value>>
+    : std::true_type {};
+template <typename T, typename SFINAE = void>
+struct move_if_unreferenced : std::false_type {};
+template <typename T>
+struct move_if_unreferenced<
+    T,
+    enable_if_t<
+        all_of<move_is_plain_type<T>,
+               negation<move_always<T>>,
+               std::is_move_constructible<T>,
+               std::is_same<decltype(std::declval<make_caster<T>>().operator T &()), T &>>::value>>
+    : std::true_type {};
+template <typename T>
+using move_never = none_of<move_always<T>, move_if_unreferenced<T>>;
 
 // Detect whether returning a `type` from a cast on type's type_caster is going to result in a
 // reference or pointer to a local variable of the type_caster.  Basically, only
 // non-reference/pointer `type`s and reference/pointers from a type_caster_generic are safe;
 // everything else returns a reference/pointer to a local variable.
-template <typename type> using cast_is_temporary_value_reference = bool_constant<
-    (std::is_reference<type>::value || std::is_pointer<type>::value) &&
-    !std::is_base_of<type_caster_generic, make_caster<type>>::value &&
-    !std::is_same<intrinsic_t<type>, void>::value
->;
+template <typename type>
+using cast_is_temporary_value_reference
+    = bool_constant<(std::is_reference<type>::value || std::is_pointer<type>::value)
+                    && !std::is_base_of<type_caster_generic, make_caster<type>>::value
+                    && !std::is_same<intrinsic_t<type>, void>::value>;
 
 // When a value returned from a C++ function is being cast back to Python, we almost always want to
 // force `policy = move`, regardless of the return value policy the function/method was declared
 // with.
-template <typename Return, typename SFINAE = void> struct return_value_policy_override {
+template <typename Return, typename SFINAE = void>
+struct return_value_policy_override {
     static return_value_policy policy(return_value_policy p) { return p; }
 };
 
-template <typename Return> struct return_value_policy_override<Return,
-        detail::enable_if_t<std::is_base_of<type_caster_generic, make_caster<Return>>::value, void>> {
+template <typename Return>
+struct return_value_policy_override<
+    Return,
+    detail::enable_if_t<std::is_base_of<type_caster_generic, make_caster<Return>>::value, void>> {
     static return_value_policy policy(return_value_policy p) {
-        return !std::is_lvalue_reference<Return>::value &&
-               !std::is_pointer<Return>::value
-                   ? return_value_policy::move : p;
+        return !std::is_lvalue_reference<Return>::value && !std::is_pointer<Return>::value
+                   ? return_value_policy::move
+                   : p;
     }
 };
 
 // Basic python -> C++ casting; throws if casting fails
-template <typename T, typename SFINAE> type_caster<T, SFINAE> &load_type(type_caster<T, SFINAE> &conv, const handle &handle) {
+template <typename T, typename SFINAE>
+type_caster<T, SFINAE> &load_type(type_caster<T, SFINAE> &conv, const handle &handle) {
     if (!conv.load(handle, true)) {
 #if defined(NDEBUG)
-        throw cast_error("Unable to cast Python instance to C++ type (compile in debug mode for details)");
+        throw cast_error(
+            "Unable to cast Python instance to C++ type (compile in debug mode for details)");
 #else
-        throw cast_error("Unable to cast Python instance of type " +
-            (std::string) str(type::handle_of(handle)) + " to C++ type '" + type_id<T>() + "'");
+        throw cast_error("Unable to cast Python instance of type "
+                         + (std::string) str(type::handle_of(handle)) + " to C++ type '"
+                         + type_id<T>() + "'");
 #endif
     }
     return conv;
 }
 // Wrapper around the above that also constructs and returns a type_caster
-template <typename T> make_caster<T> load_type(const handle &handle) {
+template <typename T>
+make_caster<T> load_type(const handle &handle) {
     make_caster<T> conv;
     load_type(conv, handle);
     return conv;
@@ -888,44 +1019,58 @@ template <typename T, detail::enable_if_t<!detail::is_pyobject<T>::value, int> =
 T cast(const handle &handle) {
     using namespace detail;
     static_assert(!cast_is_temporary_value_reference<T>::value,
-            "Unable to cast type to reference: value is local to type caster");
+                  "Unable to cast type to reference: value is local to type caster");
     return cast_op<T>(load_type<T>(handle));
 }
 
 // pytype -> pytype (calls converting constructor)
 template <typename T, detail::enable_if_t<detail::is_pyobject<T>::value, int> = 0>
-T cast(const handle &handle) { return T(reinterpret_borrow<object>(handle)); }
+T cast(const handle &handle) {
+    return T(reinterpret_borrow<object>(handle));
+}
 
 // C++ type -> py::object
 template <typename T, detail::enable_if_t<!detail::is_pyobject<T>::value, int> = 0>
-object cast(T &&value, return_value_policy policy = return_value_policy::automatic_reference,
+object cast(T &&value,
+            return_value_policy policy = return_value_policy::automatic_reference,
             handle parent = handle()) {
     using no_ref_T = typename std::remove_reference<T>::type;
     if (policy == return_value_policy::automatic)
-        policy = std::is_pointer<no_ref_T>::value ? return_value_policy::take_ownership :
-                 std::is_lvalue_reference<T>::value ? return_value_policy::copy : return_value_policy::move;
+        policy = std::is_pointer<no_ref_T>::value     ? return_value_policy::take_ownership
+                 : std::is_lvalue_reference<T>::value ? return_value_policy::copy
+                                                      : return_value_policy::move;
     else if (policy == return_value_policy::automatic_reference)
-        policy = std::is_pointer<no_ref_T>::value ? return_value_policy::reference :
-                 std::is_lvalue_reference<T>::value ? return_value_policy::copy : return_value_policy::move;
-    return reinterpret_steal<object>(detail::make_caster<T>::cast(std::forward<T>(value), policy, parent));
+        policy = std::is_pointer<no_ref_T>::value     ? return_value_policy::reference
+                 : std::is_lvalue_reference<T>::value ? return_value_policy::copy
+                                                      : return_value_policy::move;
+    return reinterpret_steal<object>(
+        detail::make_caster<T>::cast(std::forward<T>(value), policy, parent));
 }
 
-template <typename T> T handle::cast() const { return pybind11::cast<T>(*this); }
-template <> inline void handle::cast() const { return; }
+template <typename T>
+T handle::cast() const {
+    return pybind11::cast<T>(*this);
+}
+template <>
+inline void handle::cast() const {
+    return;
+}
 
 template <typename T>
 detail::enable_if_t<!detail::move_never<T>::value, T> move(object &&obj) {
     if (obj.ref_count() > 1)
 #if defined(NDEBUG)
-        throw cast_error("Unable to cast Python instance to C++ rvalue: instance has multiple references"
+        throw cast_error(
+            "Unable to cast Python instance to C++ rvalue: instance has multiple references"
             " (compile in debug mode for details)");
 #else
-        throw cast_error("Unable to move from Python " + (std::string) str(type::handle_of(obj)) +
-                " instance to C++ " + type_id<T>() + " instance: instance has multiple references");
+        throw cast_error("Unable to move from Python " + (std::string) str(type::handle_of(obj))
+                         + " instance to C++ " + type_id<T>()
+                         + " instance: instance has multiple references");
 #endif
 
     // Move into a temporary and return that, because the reference may be a local value of `conv`
-    T ret = std::move(detail::load_type<T>(obj).operator T&());
+    T ret = std::move(detail::load_type<T>(obj).operator T &());
     return ret;
 }
 
@@ -934,49 +1079,79 @@ detail::enable_if_t<!detail::move_never<T>::value, T> move(object &&obj) {
 //   object has multiple references, but trying to copy will fail to compile.
 // - If both movable and copyable, check ref count: if 1, move; otherwise copy
 // - Otherwise (not movable), copy.
-template <typename T> detail::enable_if_t<detail::move_always<T>::value, T> cast(object &&object) {
+template <typename T>
+detail::enable_if_t<detail::move_always<T>::value, T> cast(object &&object) {
     return move<T>(std::move(object));
 }
-template <typename T> detail::enable_if_t<detail::move_if_unreferenced<T>::value, T> cast(object &&object) {
+template <typename T>
+detail::enable_if_t<detail::move_if_unreferenced<T>::value, T> cast(object &&object) {
     if (object.ref_count() > 1)
         return cast<T>(object);
     return move<T>(std::move(object));
 }
-template <typename T> detail::enable_if_t<detail::move_never<T>::value, T> cast(object &&object) {
+template <typename T>
+detail::enable_if_t<detail::move_never<T>::value, T> cast(object &&object) {
     return cast<T>(object);
 }
 
-template <typename T> T object::cast() const & { return pybind11::cast<T>(*this); }
-template <typename T> T object::cast() && { return pybind11::cast<T>(std::move(*this)); }
-template <> inline void object::cast() const & { return; }
-template <> inline void object::cast() && { return; }
+template <typename T>
+T object::cast() const & {
+    return pybind11::cast<T>(*this);
+}
+template <typename T>
+T object::cast() && {
+    return pybind11::cast<T>(std::move(*this));
+}
+template <>
+inline void object::cast() const & {
+    return;
+}
+template <>
+inline void object::cast() && {
+    return;
+}
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 // Declared in pytypes.h:
 template <typename T, enable_if_t<!is_pyobject<T>::value, int>>
-object object_or_cast(T &&o) { return pybind11::cast(std::forward<T>(o)); }
+object object_or_cast(T &&o) {
+    return pybind11::cast(std::forward<T>(o));
+}
 
-struct override_unused {}; // Placeholder type for the unneeded (and dead code) static variable in the PYBIND11_OVERRIDE_OVERRIDE macro
-template <typename ret_type> using override_caster_t = conditional_t<
-    cast_is_temporary_value_reference<ret_type>::value, make_caster<ret_type>, override_unused>;
+struct override_unused {}; // Placeholder type for the unneeded (and dead code) static variable in
+                           // the PYBIND11_OVERRIDE_OVERRIDE macro
+template <typename ret_type>
+using override_caster_t = conditional_t<cast_is_temporary_value_reference<ret_type>::value,
+                                        make_caster<ret_type>,
+                                        override_unused>;
 
 // Trampoline use: for reference/pointer types to value-converted values, we do a value cast, then
 // store the result in the given variable.  For other types, this is a no-op.
-template <typename T> enable_if_t<cast_is_temporary_value_reference<T>::value, T> cast_ref(object &&o, make_caster<T> &caster) {
+template <typename T>
+enable_if_t<cast_is_temporary_value_reference<T>::value, T> cast_ref(object &&o,
+                                                                     make_caster<T> &caster) {
     return cast_op<T>(load_type(caster, o));
 }
-template <typename T> enable_if_t<!cast_is_temporary_value_reference<T>::value, T> cast_ref(object &&, override_unused &) {
-    pybind11_fail("Internal error: cast_ref fallback invoked"); }
-
-// Trampoline use: Having a pybind11::cast with an invalid reference type is going to static_assert, even
-// though if it's in dead code, so we provide a "trampoline" to pybind11::cast that only does anything in
-// cases where pybind11::cast is valid.
-template <typename T> enable_if_t<!cast_is_temporary_value_reference<T>::value, T> cast_safe(object &&o) {
-    return pybind11::cast<T>(std::move(o)); }
-template <typename T> enable_if_t<cast_is_temporary_value_reference<T>::value, T> cast_safe(object &&) {
-    pybind11_fail("Internal error: cast_safe fallback invoked"); }
-template <> inline void cast_safe<void>(object &&) {}
+template <typename T>
+enable_if_t<!cast_is_temporary_value_reference<T>::value, T> cast_ref(object &&,
+                                                                      override_unused &) {
+    pybind11_fail("Internal error: cast_ref fallback invoked");
+}
+
+// Trampoline use: Having a pybind11::cast with an invalid reference type is going to
+// static_assert, even though if it's in dead code, so we provide a "trampoline" to pybind11::cast
+// that only does anything in cases where pybind11::cast is valid.
+template <typename T>
+enable_if_t<!cast_is_temporary_value_reference<T>::value, T> cast_safe(object &&o) {
+    return pybind11::cast<T>(std::move(o));
+}
+template <typename T>
+enable_if_t<cast_is_temporary_value_reference<T>::value, T> cast_safe(object &&) {
+    pybind11_fail("Internal error: cast_safe fallback invoked");
+}
+template <>
+inline void cast_safe<void>(object &&) {}
 
 PYBIND11_NAMESPACE_END(detail)
 
@@ -996,21 +1171,21 @@ inline cast_error cast_error_unable_to_convert_call_arg(const std::string &name,
 #endif
 
 template <return_value_policy policy = return_value_policy::automatic_reference>
-tuple make_tuple() { return tuple(0); }
+tuple make_tuple() {
+    return tuple(0);
+}
 
-template <return_value_policy policy = return_value_policy::automatic_reference,
-          typename... Args> tuple make_tuple(Args&&... args_) {
+template <return_value_policy policy = return_value_policy::automatic_reference, typename... Args>
+tuple make_tuple(Args &&...args_) {
     constexpr size_t size = sizeof...(Args);
-    std::array<object, size> args {
-        { reinterpret_steal<object>(detail::make_caster<Args>::cast(
-            std::forward<Args>(args_), policy, nullptr))... }
-    };
+    std::array<object, size> args{{reinterpret_steal<object>(
+        detail::make_caster<Args>::cast(std::forward<Args>(args_), policy, nullptr))...}};
     for (size_t i = 0; i < args.size(); i++) {
         if (!args[i]) {
 #if defined(NDEBUG)
             throw cast_error_unable_to_convert_call_arg();
 #else
-            std::array<std::string, size> argtypes { {type_id<Args>()...} };
+            std::array<std::string, size> argtypes{{type_id<Args>()...}};
             throw cast_error_unable_to_convert_call_arg(std::to_string(i), argtypes[i]);
 #endif
         }
@@ -1025,18 +1200,28 @@ template <return_value_policy policy = return_value_policy::automatic_reference,
 /// \ingroup annotations
 /// Annotation for arguments
 struct arg {
-    /// Constructs an argument with the name of the argument; if null or omitted, this is a positional argument.
-    constexpr explicit arg(const char *name = nullptr) : name(name), flag_noconvert(false), flag_none(true) { }
+    /// Constructs an argument with the name of the argument; if null or omitted, this is a
+    /// positional argument.
+    constexpr explicit arg(const char *name = nullptr)
+        : name(name), flag_noconvert(false), flag_none(true) {}
     /// Assign a value to this argument
-    template <typename T> arg_v operator=(T &&value) const;
+    template <typename T>
+    arg_v operator=(T &&value) const;
     /// Indicate that the type should not be converted in the type caster
-    arg &noconvert(bool flag = true) { flag_noconvert = flag; return *this; }
+    arg &noconvert(bool flag = true) {
+        flag_noconvert = flag;
+        return *this;
+    }
     /// Indicates that the argument should/shouldn't allow None (e.g. for nullable pointer args)
-    arg &none(bool flag = true) { flag_none = flag; return *this; }
+    arg &none(bool flag = true) {
+        flag_none = flag;
+        return *this;
+    }
 
-    const char *name; ///< If non-null, this is a named kwargs argument
-    bool flag_noconvert : 1; ///< If set, do not allow conversion (requires a supporting type caster!)
-    bool flag_none : 1; ///< If set (the default), allow None to be passed to this argument
+    const char *name;        ///< If non-null, this is a named kwargs argument
+    bool flag_noconvert : 1; ///< If set, do not allow conversion (requires a supporting type
+                             ///< caster!)
+    bool flag_none : 1;      ///< If set (the default), allow None to be passed to this argument
 };
 
 /// \ingroup annotations
@@ -1045,13 +1230,12 @@ struct arg_v : arg {
 private:
     template <typename T>
     arg_v(arg &&base, T &&x, const char *descr = nullptr)
-        : arg(base),
-          value(reinterpret_steal<object>(
-              detail::make_caster<T>::cast(x, return_value_policy::automatic, {})
-          )),
+        : arg(base), value(reinterpret_steal<object>(
+                         detail::make_caster<T>::cast(x, return_value_policy::automatic, {}))),
           descr(descr)
 #if !defined(NDEBUG)
-        , type(type_id<T>())
+          ,
+          type(type_id<T>())
 #endif
     {
         // Workaround! See:
@@ -1066,18 +1250,24 @@ struct arg_v : arg {
     /// Direct construction with name, default, and description
     template <typename T>
     arg_v(const char *name, T &&x, const char *descr = nullptr)
-        : arg_v(arg(name), std::forward<T>(x), descr) { }
+        : arg_v(arg(name), std::forward<T>(x), descr) {}
 
     /// Called internally when invoking `py::arg("a") = value`
     template <typename T>
     arg_v(const arg &base, T &&x, const char *descr = nullptr)
-        : arg_v(arg(base), std::forward<T>(x), descr) { }
+        : arg_v(arg(base), std::forward<T>(x), descr) {}
 
     /// Same as `arg::noconvert()`, but returns *this as arg_v&, not arg&
-    arg_v &noconvert(bool flag = true) { arg::noconvert(flag); return *this; }
+    arg_v &noconvert(bool flag = true) {
+        arg::noconvert(flag);
+        return *this;
+    }
 
     /// Same as `arg::nonone()`, but returns *this as arg_v&, not arg&
-    arg_v &none(bool flag = true) { arg::none(flag); return *this; }
+    arg_v &none(bool flag = true) {
+        arg::none(flag);
+        return *this;
+    }
 
     /// The default value
     object value;
@@ -1090,13 +1280,13 @@ struct arg_v : arg {
 };
 
 /// \ingroup annotations
-/// Annotation indicating that all following arguments are keyword-only; the is the equivalent of an
-/// unnamed '*' argument (in Python 3)
+/// Annotation indicating that all following arguments are keyword-only; the is the equivalent of
+/// an unnamed '*' argument (in Python 3)
 struct kw_only {};
 
 /// \ingroup annotations
-/// Annotation indicating that all previous arguments are positional-only; the is the equivalent of an
-/// unnamed '/' argument (in Python 3.8)
+/// Annotation indicating that all previous arguments are positional-only; the is the equivalent of
+/// an unnamed '/' argument (in Python 3.8)
 struct pos_only {};
 
 template <typename T>
@@ -1105,7 +1295,8 @@ arg_v arg::operator=(T &&value) const {
 }
 
 /// Alias for backward compatibility -- to be removed in version 2.0
-template <typename /*unused*/> using arg_t = arg_v;
+template <typename /*unused*/>
+using arg_t = arg_v;
 
 inline namespace literals {
 /** \rst
@@ -1116,8 +1307,10 @@ constexpr arg operator"" _a(const char *name, size_t) { return arg(name); }
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 
-template <typename T> using is_kw_only = std::is_same<intrinsic_t<T>, kw_only>;
-template <typename T> using is_pos_only = std::is_same<intrinsic_t<T>, pos_only>;
+template <typename T>
+using is_kw_only = std::is_same<intrinsic_t<T>, kw_only>;
+template <typename T>
+using is_pos_only = std::is_same<intrinsic_t<T>, pos_only>;
 
 // forward declaration (definition in attr.h)
 struct function_record;
@@ -1146,18 +1339,20 @@ struct function_call {
     handle init_self;
 };
 
-
 /// Helper class which loads arguments for C++ functions called from Python
 template <typename... Args>
 class argument_loader {
     using indices = make_index_sequence<sizeof...(Args)>;
 
-    template <typename Arg> using argument_is_args   = std::is_same<intrinsic_t<Arg>, args>;
-    template <typename Arg> using argument_is_kwargs = std::is_same<intrinsic_t<Arg>, kwargs>;
+    template <typename Arg>
+    using argument_is_args = std::is_same<intrinsic_t<Arg>, args>;
+    template <typename Arg>
+    using argument_is_kwargs = std::is_same<intrinsic_t<Arg>, kwargs>;
     // Get kwargs argument position, or -1 if not present:
     static constexpr auto kwargs_pos = constexpr_last<argument_is_kwargs, Args...>();
 
-    static_assert(kwargs_pos == -1 || kwargs_pos == (int) sizeof...(Args) - 1, "py::kwargs is only permitted as the last argument of a function");
+    static_assert(kwargs_pos == -1 || kwargs_pos == (int) sizeof...(Args) - 1,
+                  "py::kwargs is only permitted as the last argument of a function");
 
 public:
     static constexpr bool has_kwargs = kwargs_pos != -1;
@@ -1165,28 +1360,28 @@ class argument_loader {
     // py::args argument position; -1 if not present.
     static constexpr int args_pos = constexpr_last<argument_is_args, Args...>();
 
-    static_assert(args_pos == -1 || args_pos == constexpr_first<argument_is_args, Args...>(), "py::args cannot be specified more than once");
+    static_assert(args_pos == -1 || args_pos == constexpr_first<argument_is_args, Args...>(),
+                  "py::args cannot be specified more than once");
 
     static constexpr auto arg_names = concat(type_descr(make_caster<Args>::name)...);
 
-    bool load_args(function_call &call) {
-        return load_impl_sequence(call, indices{});
-    }
+    bool load_args(function_call &call) { return load_impl_sequence(call, indices{}); }
 
     template <typename Return, typename Guard, typename Func>
     // NOLINTNEXTLINE(readability-const-return-type)
     enable_if_t<!std::is_void<Return>::value, Return> call(Func &&f) && {
-        return std::move(*this).template call_impl<remove_cv_t<Return>>(std::forward<Func>(f), indices{}, Guard{});
+        return std::move(*this).template call_impl<remove_cv_t<Return>>(
+            std::forward<Func>(f), indices{}, Guard{});
     }
 
     template <typename Return, typename Guard, typename Func>
     enable_if_t<std::is_void<Return>::value, void_type> call(Func &&f) && {
-        std::move(*this).template call_impl<remove_cv_t<Return>>(std::forward<Func>(f), indices{}, Guard{});
+        std::move(*this).template call_impl<remove_cv_t<Return>>(
+            std::forward<Func>(f), indices{}, Guard{});
         return void_type();
     }
 
 private:
-
     static bool load_impl_sequence(function_call &, index_sequence<>) { return true; }
 
     template <size_t... Is>
@@ -1217,7 +1412,7 @@ class simple_collector {
 public:
     template <typename... Ts>
     explicit simple_collector(Ts &&...values)
-        : m_args(pybind11::make_tuple<policy>(std::forward<Ts>(values)...)) { }
+        : m_args(pybind11::make_tuple<policy>(std::forward<Ts>(values)...)) {}
 
     const tuple &args() const & { return m_args; }
     dict kwargs() const { return {}; }
@@ -1268,13 +1463,14 @@ class unpacking_collector {
 private:
     template <typename T>
     void process(list &args_list, T &&x) {
-        auto o = reinterpret_steal<object>(detail::make_caster<T>::cast(std::forward<T>(x), policy, {}));
+        auto o = reinterpret_steal<object>(
+            detail::make_caster<T>::cast(std::forward<T>(x), policy, {}));
         if (!o) {
 #if defined(NDEBUG)
             throw cast_error_unable_to_convert_call_arg();
 #else
-            throw cast_error_unable_to_convert_call_arg(
-                std::to_string(args_list.size()), type_id<T>());
+            throw cast_error_unable_to_convert_call_arg(std::to_string(args_list.size()),
+                                                        type_id<T>());
 #endif
         }
         args_list.append(o);
@@ -1285,7 +1481,7 @@ class unpacking_collector {
             args_list.append(a);
     }
 
-    void process(list &/*args_list*/, arg_v a) {
+    void process(list & /*args_list*/, arg_v a) {
         if (!a.name)
 #if defined(NDEBUG)
             nameless_argument_error();
@@ -1310,7 +1506,7 @@ class unpacking_collector {
         m_kwargs[a.name] = a.value;
     }
 
-    void process(list &/*args_list*/, detail::kwargs_proxy kp) {
+    void process(list & /*args_list*/, detail::kwargs_proxy kp) {
         if (!kp)
             return;
         for (auto k : reinterpret_borrow<dict>(kp)) {
@@ -1331,8 +1527,9 @@ class unpacking_collector {
                          "(compile in debug mode for details)");
     }
     [[noreturn]] static void nameless_argument_error(const std::string &type) {
-        throw type_error("Got kwargs without a name of type '" + type + "'; only named "
-                         "arguments may be passed via py::arg() to a python function call. ");
+        throw type_error("Got kwargs without a name of type '" + type
+                         + "'; only named "
+                           "arguments may be passed via py::arg() to a python function call. ");
     }
     [[noreturn]] static void multiple_values_error() {
         throw type_error("Got multiple values for keyword argument "
@@ -1353,29 +1550,30 @@ class unpacking_collector {
 // fails to compile enable_if_t<!all_of<is_positional<Args>...>::value>
 // (tested with ICC 2021.1 Beta 20200827).
 template <typename... Args>
-constexpr bool args_are_all_positional()
-{
-  return all_of<is_positional<Args>...>::value;
+constexpr bool args_are_all_positional() {
+    return all_of<is_positional<Args>...>::value;
 }
 
 /// Collect only positional arguments for a Python function call
-template <return_value_policy policy, typename... Args,
+template <return_value_policy policy,
+          typename... Args,
           typename = enable_if_t<args_are_all_positional<Args...>()>>
 simple_collector<policy> collect_arguments(Args &&...args) {
     return simple_collector<policy>(std::forward<Args>(args)...);
 }
 
 /// Collect all arguments, including keywords and unpacking (only instantiated when needed)
-template <return_value_policy policy, typename... Args,
+template <return_value_policy policy,
+          typename... Args,
           typename = enable_if_t<!args_are_all_positional<Args...>()>>
 unpacking_collector<policy> collect_arguments(Args &&...args) {
     // Following argument order rules for generalized unpacking according to PEP 448
-    static_assert(
-        constexpr_last<is_positional, Args...>() < constexpr_first<is_keyword_or_ds, Args...>()
-        && constexpr_last<is_s_unpacking, Args...>() < constexpr_first<is_ds_unpacking, Args...>(),
-        "Invalid function call: positional args must precede keywords and ** unpacking; "
-        "* unpacking must precede ** unpacking"
-    );
+    static_assert(constexpr_last<is_positional, Args...>()
+                          < constexpr_first<is_keyword_or_ds, Args...>()
+                      && constexpr_last<is_s_unpacking, Args...>()
+                             < constexpr_first<is_ds_unpacking, Args...>(),
+                  "Invalid function call: positional args must precede keywords and ** unpacking; "
+                  "* unpacking must precede ** unpacking");
     return unpacking_collector<policy>(std::forward<Args>(args)...);
 }
 
@@ -1398,25 +1596,25 @@ object object_api<Derived>::call(Args &&...args) const {
 
 PYBIND11_NAMESPACE_END(detail)
 
-
-template<typename T>
+template <typename T>
 handle type::handle_of() {
-   static_assert(
-      std::is_base_of<detail::type_caster_generic, detail::make_caster<T>>::value,
-      "py::type::of<T> only supports the case where T is a registered C++ types."
-    );
+    static_assert(std::is_base_of<detail::type_caster_generic, detail::make_caster<T>>::value,
+                  "py::type::of<T> only supports the case where T is a registered C++ types.");
 
     return detail::get_type_handle(typeid(T), true);
 }
 
-
-#define PYBIND11_MAKE_OPAQUE(...) \
-    namespace pybind11 { namespace detail { \
-        template<> class type_caster<__VA_ARGS__> : public type_caster_base<__VA_ARGS__> { }; \
-    }}
+#define PYBIND11_MAKE_OPAQUE(...)                                                                 \
+    namespace pybind11 {                                                                          \
+    namespace detail {                                                                            \
+    template <>                                                                                   \
+    class type_caster<__VA_ARGS__> : public type_caster_base<__VA_ARGS__> {};                     \
+    }                                                                                             \
+    }
 
 /// Lets you pass a type containing a `,` through a macro parameter without needing a separate
-/// typedef, e.g.: `PYBIND11_OVERRIDE(PYBIND11_TYPE(ReturnType<A, B>), PYBIND11_TYPE(Parent<C, D>), f, arg)`
+/// typedef, e.g.: `PYBIND11_OVERRIDE(PYBIND11_TYPE(ReturnType<A, B>), PYBIND11_TYPE(Parent<C, D>),
+/// f, arg)`
 #define PYBIND11_TYPE(...) __VA_ARGS__
 
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
diff --git a/include/pybind11/chrono.h b/include/pybind11/chrono.h
index 460a28fa5d..864fed6943 100644
--- a/include/pybind11/chrono.h
+++ b/include/pybind11/chrono.h
@@ -15,61 +15,70 @@
 #include <chrono>
 #include <cmath>
 #include <ctime>
-#include <mutex>
-
 #include <datetime.h>
+#include <mutex>
 
 // Backport the PyDateTime_DELTA functions from Python3.3 if required
 #ifndef PyDateTime_DELTA_GET_DAYS
-#define PyDateTime_DELTA_GET_DAYS(o)         (((PyDateTime_Delta*)o)->days)
+#    define PyDateTime_DELTA_GET_DAYS(o) (((PyDateTime_Delta *) o)->days)
 #endif
 #ifndef PyDateTime_DELTA_GET_SECONDS
-#define PyDateTime_DELTA_GET_SECONDS(o)      (((PyDateTime_Delta*)o)->seconds)
+#    define PyDateTime_DELTA_GET_SECONDS(o) (((PyDateTime_Delta *) o)->seconds)
 #endif
 #ifndef PyDateTime_DELTA_GET_MICROSECONDS
-#define PyDateTime_DELTA_GET_MICROSECONDS(o) (((PyDateTime_Delta*)o)->microseconds)
+#    define PyDateTime_DELTA_GET_MICROSECONDS(o) (((PyDateTime_Delta *) o)->microseconds)
 #endif
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 PYBIND11_NAMESPACE_BEGIN(detail)
 
-template <typename type> class duration_caster {
+template <typename type>
+class duration_caster {
 public:
     using rep = typename type::rep;
     using period = typename type::period;
 
-    using days = std::chrono::duration<int_least32_t, std::ratio<86400>>; // signed 25 bits required by the standard.
+    using days
+        = std::chrono::duration<int_least32_t,
+                                std::ratio<86400>>; // signed 25 bits required by the standard.
 
     bool load(handle src, bool) {
         using namespace std::chrono;
 
         // Lazy initialise the PyDateTime import
-        if (!PyDateTimeAPI) { PyDateTime_IMPORT; }
+        if (!PyDateTimeAPI) {
+            PyDateTime_IMPORT;
+        }
 
-        if (!src) return false;
+        if (!src)
+            return false;
         // If invoked with datetime.delta object
         if (PyDelta_Check(src.ptr())) {
             value = type(duration_cast<duration<rep, period>>(
-                  days(PyDateTime_DELTA_GET_DAYS(src.ptr()))
+                days(PyDateTime_DELTA_GET_DAYS(src.ptr()))
                 + seconds(PyDateTime_DELTA_GET_SECONDS(src.ptr()))
                 + microseconds(PyDateTime_DELTA_GET_MICROSECONDS(src.ptr()))));
             return true;
         }
         // If invoked with a float we assume it is seconds and convert
         if (PyFloat_Check(src.ptr())) {
-            value = type(duration_cast<duration<rep, period>>(duration<double>(PyFloat_AsDouble(src.ptr()))));
+            value = type(duration_cast<duration<rep, period>>(
+                duration<double>(PyFloat_AsDouble(src.ptr()))));
             return true;
         }
         return false;
     }
 
     // If this is a duration just return it back
-    static const std::chrono::duration<rep, period>& get_duration(const std::chrono::duration<rep, period> &src) {
+    static const std::chrono::duration<rep, period> &
+    get_duration(const std::chrono::duration<rep, period> &src) {
         return src;
     }
 
     // If this is a time_point get the time_since_epoch
-    template <typename Clock> static std::chrono::duration<rep, period> get_duration(const std::chrono::time_point<Clock, std::chrono::duration<rep, period>> &src) {
+    template <typename Clock>
+    static std::chrono::duration<rep, period>
+    get_duration(const std::chrono::time_point<Clock, std::chrono::duration<rep, period>> &src) {
         return src.time_since_epoch();
     }
 
@@ -81,9 +90,12 @@ template <typename type> class duration_caster {
         auto d = get_duration(src);
 
         // Lazy initialise the PyDateTime import
-        if (!PyDateTimeAPI) { PyDateTime_IMPORT; }
+        if (!PyDateTimeAPI) {
+            PyDateTime_IMPORT;
+        }
 
-        // Declare these special duration types so the conversions happen with the correct primitive types (int)
+        // Declare these special duration types so the conversions happen with the correct
+        // primitive types (int)
         using dd_t = duration<int, std::ratio<86400>>;
         using ss_t = duration<int, std::ratio<1>>;
         using us_t = duration<int, std::micro>;
@@ -115,71 +127,80 @@ inline std::tm *localtime_thread_safe(const std::time_t *time, std::tm *buf) {
 }
 
 // This is for casting times on the system clock into datetime.datetime instances
-template <typename Duration> class type_caster<std::chrono::time_point<std::chrono::system_clock, Duration>> {
+template <typename Duration>
+class type_caster<std::chrono::time_point<std::chrono::system_clock, Duration>> {
 public:
     using type = std::chrono::time_point<std::chrono::system_clock, Duration>;
     bool load(handle src, bool) {
         using namespace std::chrono;
 
         // Lazy initialise the PyDateTime import
-        if (!PyDateTimeAPI) { PyDateTime_IMPORT; }
+        if (!PyDateTimeAPI) {
+            PyDateTime_IMPORT;
+        }
 
-        if (!src) return false;
+        if (!src)
+            return false;
 
         std::tm cal;
         microseconds msecs;
 
         if (PyDateTime_Check(src.ptr())) {
-            cal.tm_sec   = PyDateTime_DATE_GET_SECOND(src.ptr());
-            cal.tm_min   = PyDateTime_DATE_GET_MINUTE(src.ptr());
-            cal.tm_hour  = PyDateTime_DATE_GET_HOUR(src.ptr());
-            cal.tm_mday  = PyDateTime_GET_DAY(src.ptr());
-            cal.tm_mon   = PyDateTime_GET_MONTH(src.ptr()) - 1;
-            cal.tm_year  = PyDateTime_GET_YEAR(src.ptr()) - 1900;
+            cal.tm_sec = PyDateTime_DATE_GET_SECOND(src.ptr());
+            cal.tm_min = PyDateTime_DATE_GET_MINUTE(src.ptr());
+            cal.tm_hour = PyDateTime_DATE_GET_HOUR(src.ptr());
+            cal.tm_mday = PyDateTime_GET_DAY(src.ptr());
+            cal.tm_mon = PyDateTime_GET_MONTH(src.ptr()) - 1;
+            cal.tm_year = PyDateTime_GET_YEAR(src.ptr()) - 1900;
             cal.tm_isdst = -1;
-            msecs        = microseconds(PyDateTime_DATE_GET_MICROSECOND(src.ptr()));
+            msecs = microseconds(PyDateTime_DATE_GET_MICROSECOND(src.ptr()));
         } else if (PyDate_Check(src.ptr())) {
-            cal.tm_sec   = 0;
-            cal.tm_min   = 0;
-            cal.tm_hour  = 0;
-            cal.tm_mday  = PyDateTime_GET_DAY(src.ptr());
-            cal.tm_mon   = PyDateTime_GET_MONTH(src.ptr()) - 1;
-            cal.tm_year  = PyDateTime_GET_YEAR(src.ptr()) - 1900;
+            cal.tm_sec = 0;
+            cal.tm_min = 0;
+            cal.tm_hour = 0;
+            cal.tm_mday = PyDateTime_GET_DAY(src.ptr());
+            cal.tm_mon = PyDateTime_GET_MONTH(src.ptr()) - 1;
+            cal.tm_year = PyDateTime_GET_YEAR(src.ptr()) - 1900;
             cal.tm_isdst = -1;
-            msecs        = microseconds(0);
+            msecs = microseconds(0);
         } else if (PyTime_Check(src.ptr())) {
-            cal.tm_sec   = PyDateTime_TIME_GET_SECOND(src.ptr());
-            cal.tm_min   = PyDateTime_TIME_GET_MINUTE(src.ptr());
-            cal.tm_hour  = PyDateTime_TIME_GET_HOUR(src.ptr());
-            cal.tm_mday  = 1;   // This date (day, month, year) = (1, 0, 70)
-            cal.tm_mon   = 0;   // represents 1-Jan-1970, which is the first
-            cal.tm_year  = 70;  // earliest available date for Python's datetime
+            cal.tm_sec = PyDateTime_TIME_GET_SECOND(src.ptr());
+            cal.tm_min = PyDateTime_TIME_GET_MINUTE(src.ptr());
+            cal.tm_hour = PyDateTime_TIME_GET_HOUR(src.ptr());
+            cal.tm_mday = 1;  // This date (day, month, year) = (1, 0, 70)
+            cal.tm_mon = 0;   // represents 1-Jan-1970, which is the first
+            cal.tm_year = 70; // earliest available date for Python's datetime
             cal.tm_isdst = -1;
-            msecs        = microseconds(PyDateTime_TIME_GET_MICROSECOND(src.ptr()));
-        }
-        else return false;
+            msecs = microseconds(PyDateTime_TIME_GET_MICROSECOND(src.ptr()));
+        } else
+            return false;
 
         value = time_point_cast<Duration>(system_clock::from_time_t(std::mktime(&cal)) + msecs);
         return true;
     }
 
-    static handle cast(const std::chrono::time_point<std::chrono::system_clock, Duration> &src, return_value_policy /* policy */, handle /* parent */) {
+    static handle cast(const std::chrono::time_point<std::chrono::system_clock, Duration> &src,
+                       return_value_policy /* policy */,
+                       handle /* parent */) {
         using namespace std::chrono;
 
         // Lazy initialise the PyDateTime import
-        if (!PyDateTimeAPI) { PyDateTime_IMPORT; }
+        if (!PyDateTimeAPI) {
+            PyDateTime_IMPORT;
+        }
 
-        // Get out microseconds, and make sure they are positive, to avoid bug in eastern hemisphere time zones
-        // (cfr. https://github.com/pybind/pybind11/issues/2417)
+        // Get out microseconds, and make sure they are positive, to avoid bug in eastern
+        // hemisphere time zones (cfr. https://github.com/pybind/pybind11/issues/2417)
         using us_t = duration<int, std::micro>;
         auto us = duration_cast<us_t>(src.time_since_epoch() % seconds(1));
         if (us.count() < 0)
             us += seconds(1);
 
         // Subtract microseconds BEFORE `system_clock::to_time_t`, because:
-        // > If std::time_t has lower precision, it is implementation-defined whether the value is rounded or truncated.
-        // (https://en.cppreference.com/w/cpp/chrono/system_clock/to_time_t)
-        std::time_t tt = system_clock::to_time_t(time_point_cast<system_clock::duration>(src - us));
+        // > If std::time_t has lower precision, it is implementation-defined whether the value is
+        // rounded or truncated. (https://en.cppreference.com/w/cpp/chrono/system_clock/to_time_t)
+        std::time_t tt
+            = system_clock::to_time_t(time_point_cast<system_clock::duration>(src - us));
 
         std::tm localtime;
         std::tm *localtime_ptr = localtime_thread_safe(&tt, &localtime);
@@ -199,13 +220,13 @@ template <typename Duration> class type_caster<std::chrono::time_point<std::chro
 // Other clocks that are not the system clock are not measured as datetime.datetime objects
 // since they are not measured on calendar time. So instead we just make them timedeltas
 // Or if they have passed us a time as a float we convert that
-template <typename Clock, typename Duration> class type_caster<std::chrono::time_point<Clock, Duration>>
-: public duration_caster<std::chrono::time_point<Clock, Duration>> {
-};
+template <typename Clock, typename Duration>
+class type_caster<std::chrono::time_point<Clock, Duration>>
+    : public duration_caster<std::chrono::time_point<Clock, Duration>> {};
 
-template <typename Rep, typename Period> class type_caster<std::chrono::duration<Rep, Period>>
-: public duration_caster<std::chrono::duration<Rep, Period>> {
-};
+template <typename Rep, typename Period>
+class type_caster<std::chrono::duration<Rep, Period>>
+    : public duration_caster<std::chrono::duration<Rep, Period>> {};
 
 PYBIND11_NAMESPACE_END(detail)
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
diff --git a/include/pybind11/complex.h b/include/pybind11/complex.h
index e1ecf43585..0470ae5573 100644
--- a/include/pybind11/complex.h
+++ b/include/pybind11/complex.h
@@ -10,36 +10,42 @@
 #pragma once
 
 #include "pybind11.h"
+
 #include <complex>
 
 /// glibc defines I as a macro which breaks things, e.g., boost template names
 #ifdef I
-#  undef I
+#    undef I
 #endif
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 
-template <typename T> struct format_descriptor<std::complex<T>, detail::enable_if_t<std::is_floating_point<T>::value>> {
+template <typename T>
+struct format_descriptor<std::complex<T>, detail::enable_if_t<std::is_floating_point<T>::value>> {
     static constexpr const char c = format_descriptor<T>::c;
-    static constexpr const char value[3] = { 'Z', c, '\0' };
+    static constexpr const char value[3] = {'Z', c, '\0'};
     static std::string format() { return std::string(value); }
 };
 
 #ifndef PYBIND11_CPP17
 
-template <typename T> constexpr const char format_descriptor<
-    std::complex<T>, detail::enable_if_t<std::is_floating_point<T>::value>>::value[3];
+template <typename T>
+constexpr const char
+    format_descriptor<std::complex<T>,
+                      detail::enable_if_t<std::is_floating_point<T>::value>>::value[3];
 
 #endif
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 
-template <typename T> struct is_fmt_numeric<std::complex<T>, detail::enable_if_t<std::is_floating_point<T>::value>> {
+template <typename T>
+struct is_fmt_numeric<std::complex<T>, detail::enable_if_t<std::is_floating_point<T>::value>> {
     static constexpr bool value = true;
     static constexpr int index = is_fmt_numeric<T>::index + 3;
 };
 
-template <typename T> class type_caster<std::complex<T>> {
+template <typename T>
+class type_caster<std::complex<T>> {
 public:
     bool load(handle src, bool convert) {
         if (!src)
@@ -55,7 +61,8 @@ template <typename T> class type_caster<std::complex<T>> {
         return true;
     }
 
-    static handle cast(const std::complex<T> &src, return_value_policy /* policy */, handle /* parent */) {
+    static handle
+    cast(const std::complex<T> &src, return_value_policy /* policy */, handle /* parent */) {
         return PyComplex_FromDoubles((double) src.real(), (double) src.imag());
     }
 
diff --git a/include/pybind11/detail/class.h b/include/pybind11/detail/class.h
index cc1e40ce7a..65d537a23e 100644
--- a/include/pybind11/detail/class.h
+++ b/include/pybind11/detail/class.h
@@ -16,12 +16,13 @@ PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 #if PY_VERSION_HEX >= 0x03030000 && !defined(PYPY_VERSION)
-#  define PYBIND11_BUILTIN_QUALNAME
-#  define PYBIND11_SET_OLDPY_QUALNAME(obj, nameobj)
+#    define PYBIND11_BUILTIN_QUALNAME
+#    define PYBIND11_SET_OLDPY_QUALNAME(obj, nameobj)
 #else
 // In pre-3.3 Python, we still set __qualname__ so that we can produce reliable function type
 // signatures; in 3.3+ this macro expands to nothing:
-#  define PYBIND11_SET_OLDPY_QUALNAME(obj, nameobj) setattr((PyObject *) obj, "__qualname__", nameobj)
+#    define PYBIND11_SET_OLDPY_QUALNAME(obj, nameobj)                                             \
+        setattr((PyObject *) obj, "__qualname__", nameobj)
 #endif
 
 inline std::string get_fully_qualified_tp_name(PyTypeObject *type) {
@@ -65,16 +66,16 @@ inline PyTypeObject *make_static_property_type() {
        issue no Python C API calls which could potentially invoke the
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
-    auto heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
+    auto *heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
     if (!heap_type)
         pybind11_fail("make_static_property_type(): error allocating type!");
 
     heap_type->ht_name = name_obj.inc_ref().ptr();
-#ifdef PYBIND11_BUILTIN_QUALNAME
+#    ifdef PYBIND11_BUILTIN_QUALNAME
     heap_type->ht_qualname = name_obj.inc_ref().ptr();
-#endif
+#    endif
 
-    auto type = &heap_type->ht_type;
+    auto *type = &heap_type->ht_type;
     type->tp_name = name;
     type->tp_base = type_incref(&PyProperty_Type);
     type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HEAPTYPE;
@@ -105,8 +106,10 @@ inline PyTypeObject *make_static_property_type() {
             def __set__(self, obj, value):
                 cls = obj if isinstance(obj, type) else type(obj)
                 property.__set__(self, cls, value)
-        )", Py_file_input, d.ptr(), d.ptr()
-    );
+        )",
+                                    Py_file_input,
+                                    d.ptr(),
+                                    d.ptr());
     if (result == nullptr)
         throw error_already_set();
     Py_DECREF(result);
@@ -119,7 +122,7 @@ inline PyTypeObject *make_static_property_type() {
     By default, Python replaces the `static_property` itself, but for wrapped C++ types
     we need to call `static_property.__set__()` in order to propagate the new value to
     the underlying C++ data structure. */
-extern "C" inline int pybind11_meta_setattro(PyObject* obj, PyObject* name, PyObject* value) {
+extern "C" inline int pybind11_meta_setattro(PyObject *obj, PyObject *name, PyObject *value) {
     // Use `_PyType_Lookup()` instead of `PyObject_GetAttr()` in order to get the raw
     // descriptor (`property`) instead of calling `tp_descr_get` (`property.__get__()`).
     PyObject *descr = _PyType_Lookup((PyTypeObject *) obj, name);
@@ -128,7 +131,7 @@ extern "C" inline int pybind11_meta_setattro(PyObject* obj, PyObject* name, PyOb
     //   1. `Type.static_prop = value`             --> descr_set: `Type.static_prop.__set__(value)`
     //   2. `Type.static_prop = other_static_prop` --> setattro:  replace existing `static_prop`
     //   3. `Type.regular_attribute = value`       --> setattro:  regular attribute assignment
-    const auto static_prop = (PyObject *) get_internals().static_property_type;
+    auto *const static_prop = (PyObject *) get_internals().static_property_type;
     const auto call_descr_set = (descr != nullptr) && (value != nullptr)
                                 && (PyObject_IsInstance(descr, static_prop) != 0)
                                 && (PyObject_IsInstance(value, static_prop) == 0);
@@ -177,12 +180,13 @@ extern "C" inline PyObject *pybind11_meta_call(PyObject *type, PyObject *args, P
     }
 
     // This must be a pybind11 instance
-    auto instance = reinterpret_cast<detail::instance *>(self);
+    auto *instance = reinterpret_cast<detail::instance *>(self);
 
     // Ensure that the base __init__ function(s) were called
     for (const auto &vh : values_and_holders(instance)) {
         if (!vh.holder_constructed()) {
-            PyErr_Format(PyExc_TypeError, "%.200s.__init__() must be called when overriding __init__",
+            PyErr_Format(PyExc_TypeError,
+                         "%.200s.__init__() must be called when overriding __init__",
                          get_fully_qualified_tp_name(vh.type->type).c_str());
             Py_DECREF(self);
             return nullptr;
@@ -201,9 +205,8 @@ extern "C" inline void pybind11_meta_dealloc(PyObject *obj) {
     // 1) be found in internals.registered_types_py
     // 2) have exactly one associated `detail::type_info`
     auto found_type = internals.registered_types_py.find(type);
-    if (found_type != internals.registered_types_py.end() &&
-        found_type->second.size() == 1 &&
-        found_type->second[0]->type == type) {
+    if (found_type != internals.registered_types_py.end() && found_type->second.size() == 1
+        && found_type->second[0]->type == type) {
 
         auto *tinfo = found_type->second[0];
         auto tindex = std::type_index(*tinfo->cpptype);
@@ -217,7 +220,7 @@ extern "C" inline void pybind11_meta_dealloc(PyObject *obj) {
 
         // Actually just `std::erase_if`, but that's only available in C++20
         auto &cache = internals.inactive_override_cache;
-        for (auto it = cache.begin(), last = cache.end(); it != last; ) {
+        for (auto it = cache.begin(), last = cache.end(); it != last;) {
             if (it->first == (PyObject *) tinfo->type)
                 it = cache.erase(it);
             else
@@ -233,7 +236,7 @@ extern "C" inline void pybind11_meta_dealloc(PyObject *obj) {
 /** This metaclass is assigned by default to all pybind11 types and is required in order
     for static properties to function correctly. Users may override this using `py::metaclass`.
     Return value: New reference. */
-inline PyTypeObject* make_default_metaclass() {
+inline PyTypeObject *make_default_metaclass() {
     constexpr auto *name = "pybind11_type";
     auto name_obj = reinterpret_steal<object>(PYBIND11_FROM_STRING(name));
 
@@ -241,7 +244,7 @@ inline PyTypeObject* make_default_metaclass() {
        issue no Python C API calls which could potentially invoke the
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
-    auto heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
+    auto *heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
     if (!heap_type)
         pybind11_fail("make_default_metaclass(): error allocating metaclass!");
 
@@ -250,7 +253,7 @@ inline PyTypeObject* make_default_metaclass() {
     heap_type->ht_qualname = name_obj.inc_ref().ptr();
 #endif
 
-    auto type = &heap_type->ht_type;
+    auto *type = &heap_type->ht_type;
     type->tp_name = name;
     type->tp_base = type_incref(&PyType_Type);
     type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HEAPTYPE;
@@ -275,11 +278,14 @@ inline PyTypeObject* make_default_metaclass() {
 
 /// For multiple inheritance types we need to recursively register/deregister base pointers for any
 /// base classes with pointers that are difference from the instance value pointer so that we can
-/// correctly recognize an offset base class pointer. This calls a function with any offset base ptrs.
-inline void traverse_offset_bases(void *valueptr, const detail::type_info *tinfo, instance *self,
-        bool (*f)(void * /*parentptr*/, instance * /*self*/)) {
+/// correctly recognize an offset base class pointer. This calls a function with any offset base
+/// ptrs.
+inline void traverse_offset_bases(void *valueptr,
+                                  const detail::type_info *tinfo,
+                                  instance *self,
+                                  bool (*f)(void * /*parentptr*/, instance * /*self*/)) {
     for (handle h : reinterpret_borrow<tuple>(tinfo->type->tp_bases)) {
-        if (auto parent_tinfo = get_type_info((PyTypeObject *) h.ptr())) {
+        if (auto *parent_tinfo = get_type_info((PyTypeObject *) h.ptr())) {
             for (auto &c : parent_tinfo->implicit_casts) {
                 if (c.first == tinfo->cpptype) {
                     auto *parentptr = c.second(valueptr);
@@ -322,20 +328,20 @@ inline bool deregister_instance(instance *self, void *valptr, const type_info *t
     return ret;
 }
 
-/// Instance creation function for all pybind11 types. It allocates the internal instance layout for
-/// holding C++ objects and holders.  Allocation is done lazily (the first time the instance is cast
-/// to a reference or pointer), and initialization is done by an `__init__` function.
+/// Instance creation function for all pybind11 types. It allocates the internal instance layout
+/// for holding C++ objects and holders.  Allocation is done lazily (the first time the instance is
+/// cast to a reference or pointer), and initialization is done by an `__init__` function.
 inline PyObject *make_new_instance(PyTypeObject *type) {
 #if defined(PYPY_VERSION)
-    // PyPy gets tp_basicsize wrong (issue 2482) under multiple inheritance when the first inherited
-    // object is a plain Python type (i.e. not derived from an extension type).  Fix it.
+    // PyPy gets tp_basicsize wrong (issue 2482) under multiple inheritance when the first
+    // inherited object is a plain Python type (i.e. not derived from an extension type).  Fix it.
     ssize_t instance_size = static_cast<ssize_t>(sizeof(instance));
     if (type->tp_basicsize < instance_size) {
         type->tp_basicsize = instance_size;
     }
 #endif
     PyObject *self = type->tp_alloc(type, 0);
-    auto inst = reinterpret_cast<instance *>(self);
+    auto *inst = reinterpret_cast<instance *>(self);
     // Allocate the value/holder internals:
     inst->allocate_layout();
 
@@ -360,14 +366,14 @@ extern "C" inline int pybind11_object_init(PyObject *self, PyObject *, PyObject
 
 inline void add_patient(PyObject *nurse, PyObject *patient) {
     auto &internals = get_internals();
-    auto instance = reinterpret_cast<detail::instance *>(nurse);
+    auto *instance = reinterpret_cast<detail::instance *>(nurse);
     instance->has_patients = true;
     Py_INCREF(patient);
     internals.patients[nurse].push_back(patient);
 }
 
 inline void clear_patients(PyObject *self) {
-    auto instance = reinterpret_cast<detail::instance *>(self);
+    auto *instance = reinterpret_cast<detail::instance *>(self);
     auto &internals = get_internals();
     auto pos = internals.patients.find(self);
     assert(pos != internals.patients.end());
@@ -384,7 +390,7 @@ inline void clear_patients(PyObject *self) {
 /// Clears all internal data from the instance and removes it from registered instances in
 /// preparation for deallocation.
 inline void clear_instance(PyObject *self) {
-    auto instance = reinterpret_cast<detail::instance *>(self);
+    auto *instance = reinterpret_cast<detail::instance *>(self);
 
     // Deallocate any values/holders, if present:
     for (auto &v_h : values_and_holders(instance)) {
@@ -392,8 +398,10 @@ inline void clear_instance(PyObject *self) {
 
             // We have to deregister before we call dealloc because, for virtual MI types, we still
             // need to be able to get the parent pointers.
-            if (v_h.instance_registered() && !deregister_instance(instance, v_h.value_ptr(), v_h.type))
-                pybind11_fail("pybind11_object_dealloc(): Tried to deallocate unregistered instance!");
+            if (v_h.instance_registered()
+                && !deregister_instance(instance, v_h.value_ptr(), v_h.type))
+                pybind11_fail(
+                    "pybind11_object_dealloc(): Tried to deallocate unregistered instance!");
 
             if (instance->owned || v_h.holder_constructed())
                 v_h.type->dealloc(v_h);
@@ -418,7 +426,7 @@ inline void clear_instance(PyObject *self) {
 extern "C" inline void pybind11_object_dealloc(PyObject *self) {
     clear_instance(self);
 
-    auto type = Py_TYPE(self);
+    auto *type = Py_TYPE(self);
     type->tp_free(self);
 
 #if PY_VERSION_HEX < 0x03080000
@@ -447,7 +455,7 @@ inline PyObject *make_object_base_type(PyTypeObject *metaclass) {
        issue no Python C API calls which could potentially invoke the
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
-    auto heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
+    auto *heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
     if (!heap_type)
         pybind11_fail("make_object_base_type(): error allocating type!");
 
@@ -456,7 +464,7 @@ inline PyObject *make_object_base_type(PyTypeObject *metaclass) {
     heap_type->ht_qualname = name_obj.inc_ref().ptr();
 #endif
 
-    auto type = &heap_type->ht_type;
+    auto *type = &heap_type->ht_type;
     type->tp_name = name;
     type->tp_base = type_incref(&PyBaseObject_Type);
     type->tp_basicsize = static_cast<ssize_t>(sizeof(instance));
@@ -491,7 +499,8 @@ extern "C" inline PyObject *pybind11_get_dict(PyObject *self, void *) {
 /// dynamic_attr: Support for `instance.__dict__ = dict()`.
 extern "C" inline int pybind11_set_dict(PyObject *self, PyObject *new_dict, void *) {
     if (!PyDict_Check(new_dict)) {
-        PyErr_Format(PyExc_TypeError, "__dict__ must be set to a dictionary, not a '%.200s'",
+        PyErr_Format(PyExc_TypeError,
+                     "__dict__ must be set to a dictionary, not a '%.200s'",
                      get_fully_qualified_tp_name(Py_TYPE(new_dict)).c_str());
         return -1;
     }
@@ -518,17 +527,16 @@ extern "C" inline int pybind11_clear(PyObject *self) {
 
 /// Give instances of this type a `__dict__` and opt into garbage collection.
 inline void enable_dynamic_attributes(PyHeapTypeObject *heap_type) {
-    auto type = &heap_type->ht_type;
+    auto *type = &heap_type->ht_type;
     type->tp_flags |= Py_TPFLAGS_HAVE_GC;
-    type->tp_dictoffset = type->tp_basicsize; // place dict at the end
-    type->tp_basicsize += (ssize_t)sizeof(PyObject *); // and allocate enough space for it
+    type->tp_dictoffset = type->tp_basicsize;           // place dict at the end
+    type->tp_basicsize += (ssize_t) sizeof(PyObject *); // and allocate enough space for it
     type->tp_traverse = pybind11_traverse;
     type->tp_clear = pybind11_clear;
 
     static PyGetSetDef getset[] = {
-        {const_cast<char*>("__dict__"), pybind11_get_dict, pybind11_set_dict, nullptr, nullptr},
-        {nullptr, nullptr, nullptr, nullptr, nullptr}
-    };
+        {const_cast<char *>("__dict__"), pybind11_get_dict, pybind11_set_dict, nullptr, nullptr},
+        {nullptr, nullptr, nullptr, nullptr, nullptr}};
     type->tp_getset = getset;
 }
 
@@ -568,8 +576,8 @@ extern "C" inline int pybind11_getbuffer(PyObject *obj, Py_buffer *view, int fla
         view->format = const_cast<char *>(info->format.c_str());
     if ((flags & PyBUF_STRIDES) == PyBUF_STRIDES) {
         view->ndim = (int) info->ndim;
-        view->strides = &info->strides[0];
-        view->shape = &info->shape[0];
+        view->strides = (info->strides).data();
+        view->shape = (info->shape).data();
     }
     Py_INCREF(view->obj);
     return 0;
@@ -593,7 +601,7 @@ inline void enable_buffer_protocol(PyHeapTypeObject *heap_type) {
 
 /** Create a brand new Python type according to the `type_record` specification.
     Return value: New reference. */
-inline PyObject* make_new_python_type(const type_record &rec) {
+inline PyObject *make_new_python_type(const type_record &rec) {
     auto name = reinterpret_steal<object>(PYBIND11_FROM_STRING(rec.name));
 
     auto qualname = name;
@@ -614,11 +622,11 @@ inline PyObject* make_new_python_type(const type_record &rec) {
             module_ = rec.scope.attr("__name__");
     }
 
-    auto full_name = c_str(
+    const auto *full_name = c_str(
 #if !defined(PYPY_VERSION)
         module_ ? str(module_).cast<std::string>() + "." + rec.name :
 #endif
-        rec.name);
+                rec.name);
 
     char *tp_doc = nullptr;
     if (rec.doc && options::show_user_defined_docstrings()) {
@@ -631,17 +639,16 @@ inline PyObject* make_new_python_type(const type_record &rec) {
 
     auto &internals = get_internals();
     auto bases = tuple(rec.bases);
-    auto base = (bases.empty()) ? internals.instance_base
-                                    : bases[0].ptr();
+    auto *base = (bases.empty()) ? internals.instance_base : bases[0].ptr();
 
     /* Danger zone: from now (and until PyType_Ready), make sure to
        issue no Python C API calls which could potentially invoke the
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
-    auto metaclass = rec.metaclass.ptr() ? (PyTypeObject *) rec.metaclass.ptr()
-                                         : internals.default_metaclass;
+    auto *metaclass
+        = rec.metaclass.ptr() ? (PyTypeObject *) rec.metaclass.ptr() : internals.default_metaclass;
 
-    auto heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
+    auto *heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
     if (!heap_type)
         pybind11_fail(std::string(rec.name) + ": Unable to create type object!");
 
@@ -650,10 +657,10 @@ inline PyObject* make_new_python_type(const type_record &rec) {
     heap_type->ht_qualname = qualname.inc_ref().ptr();
 #endif
 
-    auto type = &heap_type->ht_type;
+    auto *type = &heap_type->ht_type;
     type->tp_name = full_name;
     type->tp_doc = tp_doc;
-    type->tp_base = type_incref((PyTypeObject *)base);
+    type->tp_base = type_incref((PyTypeObject *) base);
     type->tp_basicsize = static_cast<ssize_t>(sizeof(instance));
     if (!bases.empty())
         type->tp_bases = bases.release().ptr();
diff --git a/include/pybind11/detail/common.h b/include/pybind11/detail/common.h
index d9f838236a..62e6a2bfcc 100644
--- a/include/pybind11/detail/common.h
+++ b/include/pybind11/detail/common.h
@@ -21,88 +21,90 @@
 #define PYBIND11_NAMESPACE_END(name) }
 
 // Robust support for some features and loading modules compiled against different pybind versions
-// requires forcing hidden visibility on pybind code, so we enforce this by setting the attribute on
-// the main `pybind11` namespace.
+// requires forcing hidden visibility on pybind code, so we enforce this by setting the attribute
+// on the main `pybind11` namespace.
 #if !defined(PYBIND11_NAMESPACE)
-#  ifdef __GNUG__
-#    define PYBIND11_NAMESPACE pybind11 __attribute__((visibility("hidden")))
-#  else
-#    define PYBIND11_NAMESPACE pybind11
-#  endif
+#    ifdef __GNUG__
+#        define PYBIND11_NAMESPACE pybind11 __attribute__((visibility("hidden")))
+#    else
+#        define PYBIND11_NAMESPACE pybind11
+#    endif
 #endif
 
 #if !(defined(_MSC_VER) && __cplusplus == 199711L)
-#  if __cplusplus >= 201402L
-#    define PYBIND11_CPP14
-#    if __cplusplus >= 201703L
-#      define PYBIND11_CPP17
-#      if __cplusplus >= 202002L
-#        define PYBIND11_CPP20
-#      endif
+#    if __cplusplus >= 201402L
+#        define PYBIND11_CPP14
+#        if __cplusplus >= 201703L
+#            define PYBIND11_CPP17
+#            if __cplusplus >= 202002L
+#                define PYBIND11_CPP20
+#            endif
+#        endif
 #    endif
-#  endif
 #elif defined(_MSC_VER) && __cplusplus == 199711L
-// MSVC sets _MSVC_LANG rather than __cplusplus (supposedly until the standard is fully implemented)
-// Unless you use the /Zc:__cplusplus flag on Visual Studio 2017 15.7 Preview 3 or newer
-#  if _MSVC_LANG >= 201402L
-#    define PYBIND11_CPP14
-#    if _MSVC_LANG > 201402L && _MSC_VER >= 1910
-#      define PYBIND11_CPP17
-#      if _MSVC_LANG >= 202002L
-#        define PYBIND11_CPP20
-#      endif
+// MSVC sets _MSVC_LANG rather than __cplusplus (supposedly until the standard is fully
+// implemented) Unless you use the /Zc:__cplusplus flag on Visual Studio 2017 15.7 Preview 3 or
+// newer
+#    if _MSVC_LANG >= 201402L
+#        define PYBIND11_CPP14
+#        if _MSVC_LANG > 201402L && _MSC_VER >= 1910
+#            define PYBIND11_CPP17
+#            if _MSVC_LANG >= 202002L
+#                define PYBIND11_CPP20
+#            endif
+#        endif
 #    endif
-#  endif
 #endif
 
 // Compiler version assertions
 #if defined(__INTEL_COMPILER)
-#  if __INTEL_COMPILER < 1800
-#    error pybind11 requires Intel C++ compiler v18 or newer
-#  elif __INTEL_COMPILER < 1900 && defined(PYBIND11_CPP14)
-#    error pybind11 supports only C++11 with Intel C++ compiler v18. Use v19 or newer for C++14.
-#  endif
+#    if __INTEL_COMPILER < 1800
+#        error pybind11 requires Intel C++ compiler v18 or newer
+#    elif __INTEL_COMPILER < 1900 && defined(PYBIND11_CPP14)
+#        error pybind11 supports only C++11 with Intel C++ compiler v18. Use v19 or newer for C++14.
+#    endif
 /* The following pragma cannot be pop'ed:
    https://community.intel.com/t5/Intel-C-Compiler/Inline-and-no-inline-warning/td-p/1216764 */
-#  pragma warning disable 2196 // warning #2196: routine is both "inline" and "noinline"
+#    pragma warning disable 2196 // warning #2196: routine is both "inline" and "noinline"
 #elif defined(__clang__) && !defined(__apple_build_version__)
-#  if __clang_major__ < 3 || (__clang_major__ == 3 && __clang_minor__ < 3)
-#    error pybind11 requires clang 3.3 or newer
-#  endif
+#    if __clang_major__ < 3 || (__clang_major__ == 3 && __clang_minor__ < 3)
+#        error pybind11 requires clang 3.3 or newer
+#    endif
 #elif defined(__clang__)
 // Apple changes clang version macros to its Xcode version; the first Xcode release based on
 // (upstream) clang 3.3 was Xcode 5:
-#  if __clang_major__ < 5
-#    error pybind11 requires Xcode/clang 5.0 or newer
-#  endif
+#    if __clang_major__ < 5
+#        error pybind11 requires Xcode/clang 5.0 or newer
+#    endif
 #elif defined(__GNUG__)
-#  if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 8)
-#    error pybind11 requires gcc 4.8 or newer
-#  endif
+#    if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 8)
+#        error pybind11 requires gcc 4.8 or newer
+#    endif
 #elif defined(_MSC_VER)
 // Pybind hits various compiler bugs in 2015u2 and earlier, and also makes use of some stl features
 // (e.g. std::negation) added in 2015u3:
-#  if _MSC_FULL_VER < 190024210
-#    error pybind11 requires MSVC 2015 update 3 or newer
-#  endif
+#    if _MSC_FULL_VER < 190024210
+#        error pybind11 requires MSVC 2015 update 3 or newer
+#    endif
 #endif
 
 #if !defined(PYBIND11_EXPORT)
-#  if defined(WIN32) || defined(_WIN32)
-#    define PYBIND11_EXPORT __declspec(dllexport)
-#  else
-#    define PYBIND11_EXPORT __attribute__ ((visibility("default")))
-#  endif
+#    if defined(WIN32) || defined(_WIN32)
+#        define PYBIND11_EXPORT __declspec(dllexport)
+#    else
+#        define PYBIND11_EXPORT __attribute__((visibility("default")))
+#    endif
 #endif
 
 #if !defined(PYBIND11_EXPORT_EXCEPTION)
-#  ifdef __MINGW32__
+#    ifdef __MINGW32__
 // workaround for:
-// error: 'dllexport' implies default visibility, but xxx has already been declared with a different visibility
-#    define PYBIND11_EXPORT_EXCEPTION
-#  else
-#    define PYBIND11_EXPORT_EXCEPTION PYBIND11_EXPORT
-#  endif
+// error: 'dllexport' implies default visibility, but xxx has already been declared with a
+// different visibility
+#        define PYBIND11_EXPORT_EXCEPTION
+#    else
+#        define PYBIND11_EXPORT_EXCEPTION PYBIND11_EXPORT
+#    endif
 #endif
 
 // For CUDA, GCC7, GCC8:
@@ -111,107 +113,106 @@
 // However, the measured shared-library size saving when using noinline are only
 // 1.7% for CUDA, -0.2% for GCC7, and 0.0% for GCC8 (using -DCMAKE_BUILD_TYPE=MinSizeRel,
 // the default under pybind11/tests).
-#if !defined(PYBIND11_NOINLINE_FORCED) && \
-    (defined(__CUDACC__) || (defined(__GNUC__) && (__GNUC__ == 7 || __GNUC__ == 8)))
-#  define PYBIND11_NOINLINE_DISABLED
+#if !defined(PYBIND11_NOINLINE_FORCED)                                                            \
+    && (defined(__CUDACC__) || (defined(__GNUC__) && (__GNUC__ == 7 || __GNUC__ == 8)))
+#    define PYBIND11_NOINLINE_DISABLED
 #endif
 
 // The PYBIND11_NOINLINE macro is for function DEFINITIONS.
 // In contrast, FORWARD DECLARATIONS should never use this macro:
 // https://stackoverflow.com/questions/9317473/forward-declaration-of-inline-functions
 #if defined(PYBIND11_NOINLINE_DISABLED) // Option for maximum portability and experimentation.
-#  define PYBIND11_NOINLINE inline
+#    define PYBIND11_NOINLINE inline
 #elif defined(_MSC_VER)
-#  define PYBIND11_NOINLINE __declspec(noinline) inline
+#    define PYBIND11_NOINLINE __declspec(noinline) inline
 #else
-#  define PYBIND11_NOINLINE __attribute__ ((noinline)) inline
+#    define PYBIND11_NOINLINE __attribute__((noinline)) inline
 #endif
 
 #if defined(__MINGW32__)
 // For unknown reasons all PYBIND11_DEPRECATED member trigger a warning when declared
 // whether it is used or not
-#  define PYBIND11_DEPRECATED(reason)
+#    define PYBIND11_DEPRECATED(reason)
 #elif defined(PYBIND11_CPP14)
-#  define PYBIND11_DEPRECATED(reason) [[deprecated(reason)]]
+#    define PYBIND11_DEPRECATED(reason) [[deprecated(reason)]]
 #else
-#  define PYBIND11_DEPRECATED(reason) __attribute__((deprecated(reason)))
+#    define PYBIND11_DEPRECATED(reason) __attribute__((deprecated(reason)))
 #endif
 
 #if defined(PYBIND11_CPP17)
-#  define PYBIND11_MAYBE_UNUSED [[maybe_unused]]
+#    define PYBIND11_MAYBE_UNUSED [[maybe_unused]]
 #elif defined(_MSC_VER) && !defined(__clang__)
-#  define PYBIND11_MAYBE_UNUSED
+#    define PYBIND11_MAYBE_UNUSED
 #else
-#  define PYBIND11_MAYBE_UNUSED __attribute__ ((__unused__))
+#    define PYBIND11_MAYBE_UNUSED __attribute__((__unused__))
 #endif
 
 /* Don't let Python.h #define (v)snprintf as macro because they are implemented
    properly in Visual Studio since 2015. */
 #if defined(_MSC_VER) && _MSC_VER >= 1900
-#  define HAVE_SNPRINTF 1
+#    define HAVE_SNPRINTF 1
 #endif
 
 /// Include Python header, disable linking to pythonX_d.lib on Windows in debug mode
 #if defined(_MSC_VER)
-#  if (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION < 4)
-#    define HAVE_ROUND 1
-#  endif
-#  pragma warning(push)
+#    if (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION < 4)
+#        define HAVE_ROUND 1
+#    endif
+#    pragma warning(push)
 // C4505: 'PySlice_GetIndicesEx': unreferenced local function has been removed (PyPy only)
-#  pragma warning(disable: 4505)
-#  if defined(_DEBUG) && !defined(Py_DEBUG)
+#    pragma warning(disable : 4505)
+#    if defined(_DEBUG) && !defined(Py_DEBUG)
 // Workaround for a VS 2022 issue.
 // NOTE: This workaround knowingly violates the Python.h include order requirement:
 // https://docs.python.org/3/c-api/intro.html#include-files
 // See https://github.com/pybind/pybind11/pull/3497 for full context.
-#    include <yvals.h>
-#    if _MSVC_STL_VERSION >= 143
-#      include <crtdefs.h>
+#        include <yvals.h>
+#        if _MSVC_STL_VERSION >= 143
+#            include <crtdefs.h>
+#        endif
+#        define PYBIND11_DEBUG_MARKER
+#        undef _DEBUG
 #    endif
-#    define PYBIND11_DEBUG_MARKER
-#    undef _DEBUG
-#  endif
 #endif
 
 // https://en.cppreference.com/w/c/chrono/localtime
 #if defined(__STDC_LIB_EXT1__) && !defined(__STDC_WANT_LIB_EXT1__)
-#  define __STDC_WANT_LIB_EXT1__
+#    define __STDC_WANT_LIB_EXT1__
 #endif
 
 #ifdef __has_include
 // std::optional (but including it in c++14 mode isn't allowed)
-#  if defined(PYBIND11_CPP17) && __has_include(<optional>)
-#    define PYBIND11_HAS_OPTIONAL 1
-#  endif
+#    if defined(PYBIND11_CPP17) && __has_include(<optional>)
+#        define PYBIND11_HAS_OPTIONAL 1
+#    endif
 // std::experimental::optional (but not allowed in c++11 mode)
-#  if defined(PYBIND11_CPP14) && (__has_include(<experimental/optional>) && \
+#    if defined(PYBIND11_CPP14) && (__has_include(<experimental/optional>) && \
                                  !__has_include(<optional>))
-#    define PYBIND11_HAS_EXP_OPTIONAL 1
-#  endif
+#        define PYBIND11_HAS_EXP_OPTIONAL 1
+#    endif
 // std::variant
-#  if defined(PYBIND11_CPP17) && __has_include(<variant>)
-#    define PYBIND11_HAS_VARIANT 1
-#  endif
+#    if defined(PYBIND11_CPP17) && __has_include(<variant>)
+#        define PYBIND11_HAS_VARIANT 1
+#    endif
 #elif defined(_MSC_VER) && defined(PYBIND11_CPP17)
-#  define PYBIND11_HAS_OPTIONAL 1
-#  define PYBIND11_HAS_VARIANT 1
+#    define PYBIND11_HAS_OPTIONAL 1
+#    define PYBIND11_HAS_VARIANT 1
 #endif
 
 #if defined(PYBIND11_CPP17)
-#  if defined(__has_include)
-#    if __has_include(<string_view>)
-#      define PYBIND11_HAS_STRING_VIEW
+#    if defined(__has_include)
+#        if __has_include(<string_view>)
+#            define PYBIND11_HAS_STRING_VIEW
+#        endif
+#    elif defined(_MSC_VER)
+#        define PYBIND11_HAS_STRING_VIEW
 #    endif
-#  elif defined(_MSC_VER)
-#    define PYBIND11_HAS_STRING_VIEW
-#  endif
 #endif
 
 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
-#  define PYBIND11_HAS_U8STRING
+#    define PYBIND11_HAS_U8STRING
 #endif
 
-
 #include <Python.h>
 #include <frameobject.h>
 #include <pythread.h>
@@ -220,43 +221,43 @@
    tends to weak havok in C++ codebases that expect these to work
    like regular functions (potentially with several overloads) */
 #if defined(isalnum)
-#  undef isalnum
-#  undef isalpha
-#  undef islower
-#  undef isspace
-#  undef isupper
-#  undef tolower
-#  undef toupper
+#    undef isalnum
+#    undef isalpha
+#    undef islower
+#    undef isspace
+#    undef isupper
+#    undef tolower
+#    undef toupper
 #endif
 
 #if defined(copysign)
-#  undef copysign
+#    undef copysign
 #endif
 
 #if defined(_MSC_VER)
-#  if defined(PYBIND11_DEBUG_MARKER)
-#    define _DEBUG
-#    undef PYBIND11_DEBUG_MARKER
-#  endif
-#  pragma warning(pop)
+#    if defined(PYBIND11_DEBUG_MARKER)
+#        define _DEBUG
+#        undef PYBIND11_DEBUG_MARKER
+#    endif
+#    pragma warning(pop)
 #endif
 
 #include <cstddef>
 #include <cstring>
-#include <forward_list>
-#include <vector>
-#include <string>
-#include <stdexcept>
 #include <exception>
-#include <unordered_set>
-#include <unordered_map>
+#include <forward_list>
 #include <memory>
-#include <typeindex>
+#include <stdexcept>
+#include <string>
 #include <type_traits>
+#include <typeindex>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
 #if defined(__has_include)
-#  if __has_include(<version>)
-#    include <version>
-#  endif
+#    if __has_include(<version>)
+#        include <version>
+#    endif
 #endif
 
 // #define PYBIND11_STR_LEGACY_PERMISSIVE
@@ -273,70 +274,71 @@
 //               behavior.
 
 #if PY_MAJOR_VERSION >= 3 /// Compatibility macros for various Python versions
-#define PYBIND11_INSTANCE_METHOD_NEW(ptr, class_) PyInstanceMethod_New(ptr)
-#define PYBIND11_INSTANCE_METHOD_CHECK PyInstanceMethod_Check
-#define PYBIND11_INSTANCE_METHOD_GET_FUNCTION PyInstanceMethod_GET_FUNCTION
-#define PYBIND11_BYTES_CHECK PyBytes_Check
-#define PYBIND11_BYTES_FROM_STRING PyBytes_FromString
-#define PYBIND11_BYTES_FROM_STRING_AND_SIZE PyBytes_FromStringAndSize
-#define PYBIND11_BYTES_AS_STRING_AND_SIZE PyBytes_AsStringAndSize
-#define PYBIND11_BYTES_AS_STRING PyBytes_AsString
-#define PYBIND11_BYTES_SIZE PyBytes_Size
-#define PYBIND11_LONG_CHECK(o) PyLong_Check(o)
-#define PYBIND11_LONG_AS_LONGLONG(o) PyLong_AsLongLong(o)
-#define PYBIND11_LONG_FROM_SIGNED(o) PyLong_FromSsize_t((ssize_t) (o))
-#define PYBIND11_LONG_FROM_UNSIGNED(o) PyLong_FromSize_t((size_t) (o))
-#define PYBIND11_BYTES_NAME "bytes"
-#define PYBIND11_STRING_NAME "str"
-#define PYBIND11_SLICE_OBJECT PyObject
-#define PYBIND11_FROM_STRING PyUnicode_FromString
-#define PYBIND11_STR_TYPE ::pybind11::str
-#define PYBIND11_BOOL_ATTR "__bool__"
-#define PYBIND11_NB_BOOL(ptr) ((ptr)->nb_bool)
-#define PYBIND11_BUILTINS_MODULE "builtins"
+#    define PYBIND11_INSTANCE_METHOD_NEW(ptr, class_) PyInstanceMethod_New(ptr)
+#    define PYBIND11_INSTANCE_METHOD_CHECK PyInstanceMethod_Check
+#    define PYBIND11_INSTANCE_METHOD_GET_FUNCTION PyInstanceMethod_GET_FUNCTION
+#    define PYBIND11_BYTES_CHECK PyBytes_Check
+#    define PYBIND11_BYTES_FROM_STRING PyBytes_FromString
+#    define PYBIND11_BYTES_FROM_STRING_AND_SIZE PyBytes_FromStringAndSize
+#    define PYBIND11_BYTES_AS_STRING_AND_SIZE PyBytes_AsStringAndSize
+#    define PYBIND11_BYTES_AS_STRING PyBytes_AsString
+#    define PYBIND11_BYTES_SIZE PyBytes_Size
+#    define PYBIND11_LONG_CHECK(o) PyLong_Check(o)
+#    define PYBIND11_LONG_AS_LONGLONG(o) PyLong_AsLongLong(o)
+#    define PYBIND11_LONG_FROM_SIGNED(o) PyLong_FromSsize_t((ssize_t) (o))
+#    define PYBIND11_LONG_FROM_UNSIGNED(o) PyLong_FromSize_t((size_t) (o))
+#    define PYBIND11_BYTES_NAME "bytes"
+#    define PYBIND11_STRING_NAME "str"
+#    define PYBIND11_SLICE_OBJECT PyObject
+#    define PYBIND11_FROM_STRING PyUnicode_FromString
+#    define PYBIND11_STR_TYPE ::pybind11::str
+#    define PYBIND11_BOOL_ATTR "__bool__"
+#    define PYBIND11_NB_BOOL(ptr) ((ptr)->nb_bool)
+#    define PYBIND11_BUILTINS_MODULE "builtins"
 // Providing a separate declaration to make Clang's -Wmissing-prototypes happy.
 // See comment for PYBIND11_MODULE below for why this is marked "maybe unused".
-#define PYBIND11_PLUGIN_IMPL(name) \
-    extern "C" PYBIND11_MAYBE_UNUSED PYBIND11_EXPORT PyObject *PyInit_##name(); \
-    extern "C" PYBIND11_EXPORT PyObject *PyInit_##name()
+#    define PYBIND11_PLUGIN_IMPL(name)                                                            \
+        extern "C" PYBIND11_MAYBE_UNUSED PYBIND11_EXPORT PyObject *PyInit_##name();               \
+        extern "C" PYBIND11_EXPORT PyObject *PyInit_##name()
 
 #else
-#define PYBIND11_INSTANCE_METHOD_NEW(ptr, class_) PyMethod_New(ptr, nullptr, class_)
-#define PYBIND11_INSTANCE_METHOD_CHECK PyMethod_Check
-#define PYBIND11_INSTANCE_METHOD_GET_FUNCTION PyMethod_GET_FUNCTION
-#define PYBIND11_BYTES_CHECK PyString_Check
-#define PYBIND11_BYTES_FROM_STRING PyString_FromString
-#define PYBIND11_BYTES_FROM_STRING_AND_SIZE PyString_FromStringAndSize
-#define PYBIND11_BYTES_AS_STRING_AND_SIZE PyString_AsStringAndSize
-#define PYBIND11_BYTES_AS_STRING PyString_AsString
-#define PYBIND11_BYTES_SIZE PyString_Size
-#define PYBIND11_LONG_CHECK(o) (PyInt_Check(o) || PyLong_Check(o))
-#define PYBIND11_LONG_AS_LONGLONG(o) (PyInt_Check(o) ? (long long) PyLong_AsLong(o) : PyLong_AsLongLong(o))
-#define PYBIND11_LONG_FROM_SIGNED(o) PyInt_FromSsize_t((ssize_t) o) // Returns long if needed.
-#define PYBIND11_LONG_FROM_UNSIGNED(o) PyInt_FromSize_t((size_t) o) // Returns long if needed.
-#define PYBIND11_BYTES_NAME "str"
-#define PYBIND11_STRING_NAME "unicode"
-#define PYBIND11_SLICE_OBJECT PySliceObject
-#define PYBIND11_FROM_STRING PyString_FromString
-#define PYBIND11_STR_TYPE ::pybind11::bytes
-#define PYBIND11_BOOL_ATTR "__nonzero__"
-#define PYBIND11_NB_BOOL(ptr) ((ptr)->nb_nonzero)
-#define PYBIND11_BUILTINS_MODULE "__builtin__"
+#    define PYBIND11_INSTANCE_METHOD_NEW(ptr, class_) PyMethod_New(ptr, nullptr, class_)
+#    define PYBIND11_INSTANCE_METHOD_CHECK PyMethod_Check
+#    define PYBIND11_INSTANCE_METHOD_GET_FUNCTION PyMethod_GET_FUNCTION
+#    define PYBIND11_BYTES_CHECK PyString_Check
+#    define PYBIND11_BYTES_FROM_STRING PyString_FromString
+#    define PYBIND11_BYTES_FROM_STRING_AND_SIZE PyString_FromStringAndSize
+#    define PYBIND11_BYTES_AS_STRING_AND_SIZE PyString_AsStringAndSize
+#    define PYBIND11_BYTES_AS_STRING PyString_AsString
+#    define PYBIND11_BYTES_SIZE PyString_Size
+#    define PYBIND11_LONG_CHECK(o) (PyInt_Check(o) || PyLong_Check(o))
+#    define PYBIND11_LONG_AS_LONGLONG(o)                                                          \
+        (PyInt_Check(o) ? (long long) PyLong_AsLong(o) : PyLong_AsLongLong(o))
+#    define PYBIND11_LONG_FROM_SIGNED(o) PyInt_FromSsize_t((ssize_t) o) // Returns long if needed.
+#    define PYBIND11_LONG_FROM_UNSIGNED(o) PyInt_FromSize_t((size_t) o) // Returns long if needed.
+#    define PYBIND11_BYTES_NAME "str"
+#    define PYBIND11_STRING_NAME "unicode"
+#    define PYBIND11_SLICE_OBJECT PySliceObject
+#    define PYBIND11_FROM_STRING PyString_FromString
+#    define PYBIND11_STR_TYPE ::pybind11::bytes
+#    define PYBIND11_BOOL_ATTR "__nonzero__"
+#    define PYBIND11_NB_BOOL(ptr) ((ptr)->nb_nonzero)
+#    define PYBIND11_BUILTINS_MODULE "__builtin__"
 // Providing a separate PyInit decl to make Clang's -Wmissing-prototypes happy.
 // See comment for PYBIND11_MODULE below for why this is marked "maybe unused".
-#define PYBIND11_PLUGIN_IMPL(name) \
-    static PyObject *pybind11_init_wrapper();                           \
-    extern "C" PYBIND11_MAYBE_UNUSED PYBIND11_EXPORT void init##name(); \
-    extern "C" PYBIND11_EXPORT void init##name() {                      \
-        (void)pybind11_init_wrapper();                                  \
-    }                                                                   \
-    PyObject *pybind11_init_wrapper()
+#    define PYBIND11_PLUGIN_IMPL(name)                                                            \
+        static PyObject *pybind11_init_wrapper();                                                 \
+        extern "C" PYBIND11_MAYBE_UNUSED PYBIND11_EXPORT void init##name();                       \
+        extern "C" PYBIND11_EXPORT void init##name() { (void) pybind11_init_wrapper(); }          \
+        PyObject *pybind11_init_wrapper()
 #endif
 
 #if PY_VERSION_HEX >= 0x03050000 && PY_VERSION_HEX < 0x03050200
 extern "C" {
-    struct _Py_atomic_address { void *value; };
-    PyAPI_DATA(_Py_atomic_address) _PyThreadState_Current;
+struct _Py_atomic_address {
+    void *value;
+};
+PyAPI_DATA(_Py_atomic_address) _PyThreadState_Current;
 }
 #endif
 
@@ -344,46 +346,48 @@ extern "C" {
 #define PYBIND11_STRINGIFY(x) #x
 #define PYBIND11_TOSTRING(x) PYBIND11_STRINGIFY(x)
 #define PYBIND11_CONCAT(first, second) first##second
-#define PYBIND11_ENSURE_INTERNALS_READY \
-    pybind11::detail::get_internals();
-
-#define PYBIND11_CHECK_PYTHON_VERSION \
-    {                                                                          \
-        const char *compiled_ver = PYBIND11_TOSTRING(PY_MAJOR_VERSION)         \
-            "." PYBIND11_TOSTRING(PY_MINOR_VERSION);                           \
-        const char *runtime_ver = Py_GetVersion();                             \
-        size_t len = std::strlen(compiled_ver);                                \
-        if (std::strncmp(runtime_ver, compiled_ver, len) != 0                  \
-                || (runtime_ver[len] >= '0' && runtime_ver[len] <= '9')) {     \
-            PyErr_Format(PyExc_ImportError,                                    \
-                "Python version mismatch: module was compiled for Python %s, " \
-                "but the interpreter version is incompatible: %s.",            \
-                compiled_ver, runtime_ver);                                    \
-            return nullptr;                                                    \
-        }                                                                      \
+#define PYBIND11_ENSURE_INTERNALS_READY pybind11::detail::get_internals();
+
+#define PYBIND11_CHECK_PYTHON_VERSION                                                             \
+    {                                                                                             \
+        const char *compiled_ver                                                                  \
+            = PYBIND11_TOSTRING(PY_MAJOR_VERSION) "." PYBIND11_TOSTRING(PY_MINOR_VERSION);        \
+        const char *runtime_ver = Py_GetVersion();                                                \
+        size_t len = std::strlen(compiled_ver);                                                   \
+        if (std::strncmp(runtime_ver, compiled_ver, len) != 0                                     \
+            || (runtime_ver[len] >= '0' && runtime_ver[len] <= '9')) {                            \
+            PyErr_Format(PyExc_ImportError,                                                       \
+                         "Python version mismatch: module was compiled for Python %s, "           \
+                         "but the interpreter version is incompatible: %s.",                      \
+                         compiled_ver,                                                            \
+                         runtime_ver);                                                            \
+            return nullptr;                                                                       \
+        }                                                                                         \
     }
 
 #if PY_VERSION_HEX >= 0x03030000
 
-#define PYBIND11_CATCH_INIT_EXCEPTIONS \
-        catch (pybind11::error_already_set &e) {                                 \
-            pybind11::raise_from(e, PyExc_ImportError, "initialization failed"); \
-            return nullptr;                                                      \
-        } catch (const std::exception &e) {                                      \
-            PyErr_SetString(PyExc_ImportError, e.what());                        \
-            return nullptr;                                                      \
-        }                                                                        \
+#    define PYBIND11_CATCH_INIT_EXCEPTIONS                                                        \
+        catch (pybind11::error_already_set & e) {                                                 \
+            pybind11::raise_from(e, PyExc_ImportError, "initialization failed");                  \
+            return nullptr;                                                                       \
+        }                                                                                         \
+        catch (const std::exception &e) {                                                         \
+            PyErr_SetString(PyExc_ImportError, e.what());                                         \
+            return nullptr;                                                                       \
+        }
 
 #else
 
-#define PYBIND11_CATCH_INIT_EXCEPTIONS \
-        catch (pybind11::error_already_set &e) {                               \
-            PyErr_SetString(PyExc_ImportError, e.what());                      \
-            return nullptr;                                                    \
-        } catch (const std::exception &e) {                                    \
-            PyErr_SetString(PyExc_ImportError, e.what());                      \
-            return nullptr;                                                    \
-        }                                                                      \
+#    define PYBIND11_CATCH_INIT_EXCEPTIONS                                                        \
+        catch (pybind11::error_already_set & e) {                                                 \
+            PyErr_SetString(PyExc_ImportError, e.what());                                         \
+            return nullptr;                                                                       \
+        }                                                                                         \
+        catch (const std::exception &e) {                                                         \
+            PyErr_SetString(PyExc_ImportError, e.what());                                         \
+            return nullptr;                                                                       \
+        }
 
 #endif
 
@@ -402,16 +406,17 @@ extern "C" {
             return m.ptr();
         }
 \endrst */
-#define PYBIND11_PLUGIN(name)                                                  \
-    PYBIND11_DEPRECATED("PYBIND11_PLUGIN is deprecated, use PYBIND11_MODULE")  \
-    static PyObject *pybind11_init();                                          \
-    PYBIND11_PLUGIN_IMPL(name) {                                               \
-        PYBIND11_CHECK_PYTHON_VERSION                                          \
-        PYBIND11_ENSURE_INTERNALS_READY                                        \
-        try {                                                                  \
-            return pybind11_init();                                            \
-        } PYBIND11_CATCH_INIT_EXCEPTIONS                                       \
-    }                                                                          \
+#define PYBIND11_PLUGIN(name)                                                                     \
+    PYBIND11_DEPRECATED("PYBIND11_PLUGIN is deprecated, use PYBIND11_MODULE")                     \
+    static PyObject *pybind11_init();                                                             \
+    PYBIND11_PLUGIN_IMPL(name) {                                                                  \
+        PYBIND11_CHECK_PYTHON_VERSION                                                             \
+        PYBIND11_ENSURE_INTERNALS_READY                                                           \
+        try {                                                                                     \
+            return pybind11_init();                                                               \
+        }                                                                                         \
+        PYBIND11_CATCH_INIT_EXCEPTIONS                                                            \
+    }                                                                                             \
     PyObject *pybind11_init()
 
 /** \rst
@@ -456,7 +461,7 @@ extern "C" {
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 
 using ssize_t = Py_ssize_t;
-using size_t  = std::size_t;
+using size_t = std::size_t;
 
 template <typename IntType>
 inline ssize_t ssize_t_cast(const IntType &val) {
@@ -518,10 +523,14 @@ enum class return_value_policy : uint8_t {
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 
-inline static constexpr int log2(size_t n, int k = 0) { return (n <= 1) ? k : log2(n >> 1, k + 1); }
+inline static constexpr int log2(size_t n, int k = 0) {
+    return (n <= 1) ? k : log2(n >> 1, k + 1);
+}
 
 // Returns the size as a multiple of sizeof(void *), rounded up.
-inline static constexpr size_t size_in_ptrs(size_t s) { return 1 + ((s - 1) >> log2(sizeof(void *))); }
+inline static constexpr size_t size_in_ptrs(size_t s) {
+    return 1 + ((s - 1) >> log2(sizeof(void *)));
+}
 
 /**
  * The space to allocate for simple layout instance holders (see below) in multiple of the size of
@@ -531,7 +540,7 @@ inline static constexpr size_t size_in_ptrs(size_t s) { return 1 + ((s - 1) >> l
  */
 constexpr size_t instance_simple_holder_in_ptrs() {
     static_assert(sizeof(std::shared_ptr<int>) >= sizeof(std::unique_ptr<int>),
-            "pybind assumes std::shared_ptrs are at least as big as std::unique_ptrs");
+                  "pybind assumes std::shared_ptrs are at least as big as std::unique_ptrs");
     return size_in_ptrs(sizeof(std::shared_ptr<int>));
 }
 
@@ -547,8 +556,8 @@ struct nonsimple_values_and_holders {
 /// The 'instance' type which needs to be standard layout (need to be able to use 'offsetof')
 struct instance {
     PyObject_HEAD
-    /// Storage for pointers and holder; see simple_layout, below, for a description
-    union {
+        /// Storage for pointers and holder; see simple_layout, below, for a description
+        union {
         void *simple_value_holder[1 + instance_simple_holder_in_ptrs()];
         nonsimple_values_and_holders nonsimple;
     };
@@ -559,21 +568,21 @@ struct instance {
     /**
      * An instance has two possible value/holder layouts.
      *
-     * Simple layout (when this flag is true), means the `simple_value_holder` is set with a pointer
-     * and the holder object governing that pointer, i.e. [val1*][holder].  This layout is applied
-     * whenever there is no python-side multiple inheritance of bound C++ types *and* the type's
-     * holder will fit in the default space (which is large enough to hold either a std::unique_ptr
-     * or std::shared_ptr).
+     * Simple layout (when this flag is true), means the `simple_value_holder` is set with a
+     * pointer and the holder object governing that pointer, i.e. [val1*][holder].  This layout is
+     * applied whenever there is no python-side multiple inheritance of bound C++ types *and* the
+     * type's holder will fit in the default space (which is large enough to hold either a
+     * std::unique_ptr or std::shared_ptr).
      *
-     * Non-simple layout applies when using custom holders that require more space than `shared_ptr`
-     * (which is typically the size of two pointers), or when multiple inheritance is used on the
-     * python side.  Non-simple layout allocates the required amount of memory to have multiple
-     * bound C++ classes as parents.  Under this layout, `nonsimple.values_and_holders` is set to a
-     * pointer to allocated space of the required space to hold a sequence of value pointers and
-     * holders followed `status`, a set of bit flags (1 byte each), i.e.
-     * [val1*][holder1][val2*][holder2]...[bb...]  where each [block] is rounded up to a multiple of
-     * `sizeof(void *)`.  `nonsimple.status` is, for convenience, a pointer to the
-     * beginning of the [bb...] block (but not independently allocated).
+     * Non-simple layout applies when using custom holders that require more space than
+     * `shared_ptr` (which is typically the size of two pointers), or when multiple inheritance is
+     * used on the python side.  Non-simple layout allocates the required amount of memory to have
+     * multiple bound C++ classes as parents.  Under this layout, `nonsimple.values_and_holders` is
+     * set to a pointer to allocated space of the required space to hold a sequence of value
+     * pointers and holders followed `status`, a set of bit flags (1 byte each), i.e.
+     * [val1*][holder1][val2*][holder2]...[bb...]  where each [block] is rounded up to a multiple
+     * of `sizeof(void *)`.  `nonsimple.status` is, for convenience, a pointer to the beginning of
+     * the [bb...] block (but not independently allocated).
      *
      * Status bits indicate whether the associated holder is constructed (&
      * status_holder_constructed) and whether the value pointer is registered (&
@@ -587,7 +596,8 @@ struct instance {
     /// If true, get_internals().patients has an entry for this object
     bool has_patients : 1;
 
-    /// Initializes all of the above type/values/holders data (but not the instance values themselves)
+    /// Initializes all of the above type/values/holders data (but not the instance values
+    /// themselves)
     void allocate_layout();
 
     /// Destroys/deallocates all of the above
@@ -596,26 +606,32 @@ struct instance {
     /// Returns the value_and_holder wrapper for the given type (or the first, if `find_type`
     /// omitted).  Returns a default-constructed (with `.inst = nullptr`) object on failure if
     /// `throw_if_missing` is false.
-    value_and_holder get_value_and_holder(const type_info *find_type = nullptr, bool throw_if_missing = true);
+    value_and_holder get_value_and_holder(const type_info *find_type = nullptr,
+                                          bool throw_if_missing = true);
 
     /// Bit values for the non-simple status flags
-    static constexpr uint8_t status_holder_constructed  = 1;
+    static constexpr uint8_t status_holder_constructed = 1;
     static constexpr uint8_t status_instance_registered = 2;
 };
 
-static_assert(std::is_standard_layout<instance>::value, "Internal error: `pybind11::detail::instance` is not standard layout!");
+static_assert(std::is_standard_layout<instance>::value,
+              "Internal error: `pybind11::detail::instance` is not standard layout!");
 
 /// from __cpp_future__ import (convenient aliases from C++14/17)
 #if defined(PYBIND11_CPP14) && (!defined(_MSC_VER) || _MSC_VER >= 1910)
-using std::enable_if_t;
 using std::conditional_t;
+using std::enable_if_t;
 using std::remove_cv_t;
 using std::remove_reference_t;
 #else
-template <bool B, typename T = void> using enable_if_t = typename std::enable_if<B, T>::type;
-template <bool B, typename T, typename F> using conditional_t = typename std::conditional<B, T, F>::type;
-template <typename T> using remove_cv_t = typename std::remove_cv<T>::type;
-template <typename T> using remove_reference_t = typename std::remove_reference<T>::type;
+template <bool B, typename T = void>
+using enable_if_t = typename std::enable_if<B, T>::type;
+template <bool B, typename T, typename F>
+using conditional_t = typename std::conditional<B, T, F>::type;
+template <typename T>
+using remove_cv_t = typename std::remove_cv<T>::type;
+template <typename T>
+using remove_reference_t = typename std::remove_reference<T>::type;
 #endif
 
 #if defined(PYBIND11_CPP20)
@@ -635,114 +651,189 @@ using remove_cvref_t = typename remove_cvref<T>::type;
 using std::index_sequence;
 using std::make_index_sequence;
 #else
-template<size_t ...> struct index_sequence  { };
-template<size_t N, size_t ...S> struct make_index_sequence_impl : make_index_sequence_impl <N - 1, N - 1, S...> { };
-template<size_t ...S> struct make_index_sequence_impl <0, S...> { using type = index_sequence<S...>; };
-template<size_t N> using make_index_sequence = typename make_index_sequence_impl<N>::type;
+template <size_t...>
+struct index_sequence {};
+template <size_t N, size_t... S>
+struct make_index_sequence_impl : make_index_sequence_impl<N - 1, N - 1, S...> {};
+template <size_t... S>
+struct make_index_sequence_impl<0, S...> {
+    using type = index_sequence<S...>;
+};
+template <size_t N>
+using make_index_sequence = typename make_index_sequence_impl<N>::type;
 #endif
 
 /// Make an index sequence of the indices of true arguments
-template <typename ISeq, size_t, bool...> struct select_indices_impl { using type = ISeq; };
-template <size_t... IPrev, size_t I, bool B, bool... Bs> struct select_indices_impl<index_sequence<IPrev...>, I, B, Bs...>
-    : select_indices_impl<conditional_t<B, index_sequence<IPrev..., I>, index_sequence<IPrev...>>, I + 1, Bs...> {};
-template <bool... Bs> using select_indices = typename select_indices_impl<index_sequence<>, 0, Bs...>::type;
+template <typename ISeq, size_t, bool...>
+struct select_indices_impl {
+    using type = ISeq;
+};
+template <size_t... IPrev, size_t I, bool B, bool... Bs>
+struct select_indices_impl<index_sequence<IPrev...>, I, B, Bs...>
+    : select_indices_impl<conditional_t<B, index_sequence<IPrev..., I>, index_sequence<IPrev...>>,
+                          I + 1,
+                          Bs...> {};
+template <bool... Bs>
+using select_indices = typename select_indices_impl<index_sequence<>, 0, Bs...>::type;
 
 /// Backports of std::bool_constant and std::negation to accommodate older compilers
-template <bool B> using bool_constant = std::integral_constant<bool, B>;
-template <typename T> struct negation : bool_constant<!T::value> { };
+template <bool B>
+using bool_constant = std::integral_constant<bool, B>;
+template <typename T>
+struct negation : bool_constant<!T::value> {};
 
 // PGI/Intel cannot detect operator delete with the "compatible" void_t impl, so
 // using the new one (C++14 defect, so generally works on newer compilers, even
 // if not in C++17 mode)
 #if defined(__PGIC__) || defined(__INTEL_COMPILER)
-template<typename... > using void_t = void;
+template <typename...>
+using void_t = void;
 #else
-template <typename...> struct void_t_impl { using type = void; };
-template <typename... Ts> using void_t = typename void_t_impl<Ts...>::type;
+template <typename...>
+struct void_t_impl {
+    using type = void;
+};
+template <typename... Ts>
+using void_t = typename void_t_impl<Ts...>::type;
 #endif
 
-
 /// Compile-time all/any/none of that check the boolean value of all template types
 #if defined(__cpp_fold_expressions) && !(defined(_MSC_VER) && (_MSC_VER < 1916))
-template <class... Ts> using all_of = bool_constant<(Ts::value && ...)>;
-template <class... Ts> using any_of = bool_constant<(Ts::value || ...)>;
+template <class... Ts>
+using all_of = bool_constant<(Ts::value && ...)>;
+template <class... Ts>
+using any_of = bool_constant<(Ts::value || ...)>;
 #elif !defined(_MSC_VER)
-template <bool...> struct bools {};
-template <class... Ts> using all_of = std::is_same<
-    bools<Ts::value..., true>,
-    bools<true, Ts::value...>>;
-template <class... Ts> using any_of = negation<all_of<negation<Ts>...>>;
+template <bool...>
+struct bools {};
+template <class... Ts>
+using all_of = std::is_same<bools<Ts::value..., true>, bools<true, Ts::value...>>;
+template <class... Ts>
+using any_of = negation<all_of<negation<Ts>...>>;
 #else
 // MSVC has trouble with the above, but supports std::conjunction, which we can use instead (albeit
 // at a slight loss of compilation efficiency).
-template <class... Ts> using all_of = std::conjunction<Ts...>;
-template <class... Ts> using any_of = std::disjunction<Ts...>;
+template <class... Ts>
+using all_of = std::conjunction<Ts...>;
+template <class... Ts>
+using any_of = std::disjunction<Ts...>;
 #endif
-template <class... Ts> using none_of = negation<any_of<Ts...>>;
+template <class... Ts>
+using none_of = negation<any_of<Ts...>>;
 
-template <class T, template<class> class... Predicates> using satisfies_all_of = all_of<Predicates<T>...>;
-template <class T, template<class> class... Predicates> using satisfies_any_of = any_of<Predicates<T>...>;
-template <class T, template<class> class... Predicates> using satisfies_none_of = none_of<Predicates<T>...>;
+template <class T, template <class> class... Predicates>
+using satisfies_all_of = all_of<Predicates<T>...>;
+template <class T, template <class> class... Predicates>
+using satisfies_any_of = any_of<Predicates<T>...>;
+template <class T, template <class> class... Predicates>
+using satisfies_none_of = none_of<Predicates<T>...>;
 
 /// Strip the class from a method type
-template <typename T> struct remove_class { };
-template <typename C, typename R, typename... A> struct remove_class<R (C::*)(A...)> { using type = R (A...); };
-template <typename C, typename R, typename... A> struct remove_class<R (C::*)(A...) const> { using type = R (A...); };
+template <typename T>
+struct remove_class {};
+template <typename C, typename R, typename... A>
+struct remove_class<R (C::*)(A...)> {
+    using type = R(A...);
+};
+template <typename C, typename R, typename... A>
+struct remove_class<R (C::*)(A...) const> {
+    using type = R(A...);
+};
 
 /// Helper template to strip away type modifiers
-template <typename T> struct intrinsic_type                       { using type = T; };
-template <typename T> struct intrinsic_type<const T>              { using type = typename intrinsic_type<T>::type; };
-template <typename T> struct intrinsic_type<T*>                   { using type = typename intrinsic_type<T>::type; };
-template <typename T> struct intrinsic_type<T&>                   { using type = typename intrinsic_type<T>::type; };
-template <typename T> struct intrinsic_type<T&&>                  { using type = typename intrinsic_type<T>::type; };
-template <typename T, size_t N> struct intrinsic_type<const T[N]> { using type = typename intrinsic_type<T>::type; };
-template <typename T, size_t N> struct intrinsic_type<T[N]>       { using type = typename intrinsic_type<T>::type; };
-template <typename T> using intrinsic_t = typename intrinsic_type<T>::type;
+template <typename T>
+struct intrinsic_type {
+    using type = T;
+};
+template <typename T>
+struct intrinsic_type<const T> {
+    using type = typename intrinsic_type<T>::type;
+};
+template <typename T>
+struct intrinsic_type<T *> {
+    using type = typename intrinsic_type<T>::type;
+};
+template <typename T>
+struct intrinsic_type<T &> {
+    using type = typename intrinsic_type<T>::type;
+};
+template <typename T>
+struct intrinsic_type<T &&> {
+    using type = typename intrinsic_type<T>::type;
+};
+template <typename T, size_t N>
+struct intrinsic_type<const T[N]> {
+    using type = typename intrinsic_type<T>::type;
+};
+template <typename T, size_t N>
+struct intrinsic_type<T[N]> {
+    using type = typename intrinsic_type<T>::type;
+};
+template <typename T>
+using intrinsic_t = typename intrinsic_type<T>::type;
 
 /// Helper type to replace 'void' in some expressions
-struct void_type { };
+struct void_type {};
 
 /// Helper template which holds a list of types
-template <typename...> struct type_list { };
+template <typename...>
+struct type_list {};
 
 /// Compile-time integer sum
 #ifdef __cpp_fold_expressions
-template <typename... Ts> constexpr size_t constexpr_sum(Ts... ns) { return (0 + ... + size_t{ns}); }
+template <typename... Ts>
+constexpr size_t constexpr_sum(Ts... ns) {
+    return (0 + ... + size_t{ns});
+}
 #else
 constexpr size_t constexpr_sum() { return 0; }
 template <typename T, typename... Ts>
-constexpr size_t constexpr_sum(T n, Ts... ns) { return size_t{n} + constexpr_sum(ns...); }
+constexpr size_t constexpr_sum(T n, Ts... ns) {
+    return size_t{n} + constexpr_sum(ns...);
+}
 #endif
 
 PYBIND11_NAMESPACE_BEGIN(constexpr_impl)
 /// Implementation details for constexpr functions
 constexpr int first(int i) { return i; }
 template <typename T, typename... Ts>
-constexpr int first(int i, T v, Ts... vs) { return v ? i : first(i + 1, vs...); }
+constexpr int first(int i, T v, Ts... vs) {
+    return v ? i : first(i + 1, vs...);
+}
 
 constexpr int last(int /*i*/, int result) { return result; }
 template <typename T, typename... Ts>
-constexpr int last(int i, int result, T v, Ts... vs) { return last(i + 1, v ? i : result, vs...); }
+constexpr int last(int i, int result, T v, Ts... vs) {
+    return last(i + 1, v ? i : result, vs...);
+}
 PYBIND11_NAMESPACE_END(constexpr_impl)
 
-/// Return the index of the first type in Ts which satisfies Predicate<T>.  Returns sizeof...(Ts) if
-/// none match.
-template <template<typename> class Predicate, typename... Ts>
-constexpr int constexpr_first() { return constexpr_impl::first(0, Predicate<Ts>::value...); }
+/// Return the index of the first type in Ts which satisfies Predicate<T>.  Returns sizeof...(Ts)
+/// if none match.
+template <template <typename> class Predicate, typename... Ts>
+constexpr int constexpr_first() {
+    return constexpr_impl::first(0, Predicate<Ts>::value...);
+}
 
 /// Return the index of the last type in Ts which satisfies Predicate<T>, or -1 if none match.
-template <template<typename> class Predicate, typename... Ts>
-constexpr int constexpr_last() { return constexpr_impl::last(0, -1, Predicate<Ts>::value...); }
+template <template <typename> class Predicate, typename... Ts>
+constexpr int constexpr_last() {
+    return constexpr_impl::last(0, -1, Predicate<Ts>::value...);
+}
 
 /// Return the Nth element from the parameter pack
 template <size_t N, typename T, typename... Ts>
-struct pack_element { using type = typename pack_element<N - 1, Ts...>::type; };
+struct pack_element {
+    using type = typename pack_element<N - 1, Ts...>::type;
+};
 template <typename T, typename... Ts>
-struct pack_element<0, T, Ts...> { using type = T; };
+struct pack_element<0, T, Ts...> {
+    using type = T;
+};
 
 /// Return the one and only type which matches the predicate, or Default if none match.
 /// If more than one type matches the predicate, fail at compile-time.
-template <template<typename> class Predicate, typename Default, typename... Ts>
+template <template <typename> class Predicate, typename Default, typename... Ts>
 struct exactly_one {
     static constexpr auto found = constexpr_sum(Predicate<Ts>::value...);
     static_assert(found <= 1, "Found more than one type matching the predicate");
@@ -750,62 +841,81 @@ struct exactly_one {
     static constexpr auto index = found ? constexpr_first<Predicate, Ts...>() : 0;
     using type = conditional_t<found, typename pack_element<index, Ts...>::type, Default>;
 };
-template <template<typename> class P, typename Default>
-struct exactly_one<P, Default> { using type = Default; };
+template <template <typename> class P, typename Default>
+struct exactly_one<P, Default> {
+    using type = Default;
+};
 
-template <template<typename> class Predicate, typename Default, typename... Ts>
+template <template <typename> class Predicate, typename Default, typename... Ts>
 using exactly_one_t = typename exactly_one<Predicate, Default, Ts...>::type;
 
 /// Defer the evaluation of type T until types Us are instantiated
-template <typename T, typename... /*Us*/> struct deferred_type { using type = T; };
-template <typename T, typename... Us> using deferred_t = typename deferred_type<T, Us...>::type;
+template <typename T, typename... /*Us*/>
+struct deferred_type {
+    using type = T;
+};
+template <typename T, typename... Us>
+using deferred_t = typename deferred_type<T, Us...>::type;
 
 /// Like is_base_of, but requires a strict base (i.e. `is_strict_base_of<T, T>::value == false`,
 /// unlike `std::is_base_of`)
-template <typename Base, typename Derived> using is_strict_base_of = bool_constant<
-    std::is_base_of<Base, Derived>::value && !std::is_same<Base, Derived>::value>;
-
-/// Like is_base_of, but also requires that the base type is accessible (i.e. that a Derived pointer
-/// can be converted to a Base pointer)
-/// For unions, `is_base_of<T, T>::value` is False, so we need to check `is_same` as well.
-template <typename Base, typename Derived> using is_accessible_base_of = bool_constant<
-    (std::is_same<Base, Derived>::value || std::is_base_of<Base, Derived>::value) && std::is_convertible<Derived *, Base *>::value>;
-
-template <template<typename...> class Base>
+template <typename Base, typename Derived>
+using is_strict_base_of
+    = bool_constant<std::is_base_of<Base, Derived>::value && !std::is_same<Base, Derived>::value>;
+
+/// Like is_base_of, but also requires that the base type is accessible (i.e. that a Derived
+/// pointer can be converted to a Base pointer) For unions, `is_base_of<T, T>::value` is False, so
+/// we need to check `is_same` as well.
+template <typename Base, typename Derived>
+using is_accessible_base_of
+    = bool_constant<(std::is_same<Base, Derived>::value || std::is_base_of<Base, Derived>::value)
+                    && std::is_convertible<Derived *, Base *>::value>;
+
+template <template <typename...> class Base>
 struct is_template_base_of_impl {
-    template <typename... Us> static std::true_type check(Base<Us...> *);
+    template <typename... Us>
+    static std::true_type check(Base<Us...> *);
     static std::false_type check(...);
 };
 
 /// Check if a template is the base of a type. For example:
 /// `is_template_base_of<Base, T>` is true if `struct T : Base<U> {}` where U can be anything
-template <template<typename...> class Base, typename T>
+template <template <typename...> class Base, typename T>
 #if !defined(_MSC_VER)
-using is_template_base_of = decltype(is_template_base_of_impl<Base>::check((intrinsic_t<T>*)nullptr));
+using is_template_base_of
+    = decltype(is_template_base_of_impl<Base>::check((intrinsic_t<T> *) nullptr));
 #else // MSVC2015 has trouble with decltype in template aliases
-struct is_template_base_of : decltype(is_template_base_of_impl<Base>::check((intrinsic_t<T>*)nullptr)) { };
+struct is_template_base_of
+    : decltype(is_template_base_of_impl<Base>::check((intrinsic_t<T> *) nullptr)) {
+};
 #endif
 
 /// Check if T is an instantiation of the template `Class`. For example:
 /// `is_instantiation<shared_ptr, T>` is true if `T == shared_ptr<U>` where U can be anything.
-template <template<typename...> class Class, typename T>
-struct is_instantiation : std::false_type { };
-template <template<typename...> class Class, typename... Us>
-struct is_instantiation<Class, Class<Us...>> : std::true_type { };
+template <template <typename...> class Class, typename T>
+struct is_instantiation : std::false_type {};
+template <template <typename...> class Class, typename... Us>
+struct is_instantiation<Class, Class<Us...>> : std::true_type {};
 
 /// Check if T is std::shared_ptr<U> where U can be anything
-template <typename T> using is_shared_ptr = is_instantiation<std::shared_ptr, T>;
+template <typename T>
+using is_shared_ptr = is_instantiation<std::shared_ptr, T>;
 
 /// Check if T looks like an input iterator
-template <typename T, typename = void> struct is_input_iterator : std::false_type {};
+template <typename T, typename = void>
+struct is_input_iterator : std::false_type {};
 template <typename T>
-struct is_input_iterator<T, void_t<decltype(*std::declval<T &>()), decltype(++std::declval<T &>())>>
+struct is_input_iterator<T,
+                         void_t<decltype(*std::declval<T &>()), decltype(++std::declval<T &>())>>
     : std::true_type {};
 
-template <typename T> using is_function_pointer = bool_constant<
-    std::is_pointer<T>::value && std::is_function<typename std::remove_pointer<T>::type>::value>;
+template <typename T>
+using is_function_pointer
+    = bool_constant<std::is_pointer<T>::value
+                    && std::is_function<typename std::remove_pointer<T>::type>::value>;
 
-template <typename F> struct strip_function_object {
+template <typename F>
+struct strip_function_object {
     // If you are encountering an
     // 'error: name followed by "::" must be a class or namespace name'
     // with the Intel compiler and a noexcept function here,
@@ -818,34 +928,37 @@ template <typename Function, typename F = remove_reference_t<Function>>
 using function_signature_t = conditional_t<
     std::is_function<F>::value,
     F,
-    typename conditional_t<
-        std::is_pointer<F>::value || std::is_member_pointer<F>::value,
-        std::remove_pointer<F>,
-        strip_function_object<F>
-    >::type
->;
+    typename conditional_t<std::is_pointer<F>::value || std::is_member_pointer<F>::value,
+                           std::remove_pointer<F>,
+                           strip_function_object<F>>::type>;
 
 /// Returns true if the type looks like a lambda: that is, isn't a function, pointer or member
 /// pointer.  Note that this can catch all sorts of other things, too; this is intended to be used
 /// in a place where passing a lambda makes sense.
-template <typename T> using is_lambda = satisfies_none_of<remove_reference_t<T>,
-        std::is_function, std::is_pointer, std::is_member_pointer>;
+template <typename T>
+using is_lambda = satisfies_none_of<remove_reference_t<T>,
+                                    std::is_function,
+                                    std::is_pointer,
+                                    std::is_member_pointer>;
 
 // [workaround(intel)] Internal error on fold expression
 /// Apply a function over each element of a parameter pack
 #if defined(__cpp_fold_expressions) && !defined(__INTEL_COMPILER)
 // Intel compiler produces an internal error on this fold expression (tested with ICC 19.0.2)
-#define PYBIND11_EXPAND_SIDE_EFFECTS(PATTERN) (((PATTERN), void()), ...)
+#    define PYBIND11_EXPAND_SIDE_EFFECTS(PATTERN) (((PATTERN), void()), ...)
 #else
 using expand_side_effects = bool[];
-#define PYBIND11_EXPAND_SIDE_EFFECTS(PATTERN) (void)pybind11::detail::expand_side_effects{ ((PATTERN), void(), false)..., false }
+#    define PYBIND11_EXPAND_SIDE_EFFECTS(PATTERN)                                                 \
+        (void) pybind11::detail::expand_side_effects { ((PATTERN), void(), false)..., false }
 #endif
 
 PYBIND11_NAMESPACE_END(detail)
 
 #if defined(_MSC_VER)
-#  pragma warning(push)
-#  pragma warning(disable: 4275) // warning C4275: An exported class was derived from a class that wasn't exported. Can be ignored when derived from a STL class.
+#    pragma warning(push)
+#    pragma warning(disable : 4275)
+//       warning C4275: An exported class was derived from a class that wasn't exported.
+//       Can be ignored when derived from a STL class.
 #endif
 /// C++ bindings of builtin Python exceptions
 class PYBIND11_EXPORT_EXCEPTION builtin_exception : public std::runtime_error {
@@ -855,14 +968,15 @@ class PYBIND11_EXPORT_EXCEPTION builtin_exception : public std::runtime_error {
     virtual void set_error() const = 0;
 };
 #if defined(_MSC_VER)
-#  pragma warning(pop)
+#    pragma warning(pop)
 #endif
 
-#define PYBIND11_RUNTIME_EXCEPTION(name, type) \
-    class PYBIND11_EXPORT_EXCEPTION name : public builtin_exception { public: \
-        using builtin_exception::builtin_exception; \
-        name() : name("") { } \
-        void set_error() const override { PyErr_SetString(type, what()); } \
+#define PYBIND11_RUNTIME_EXCEPTION(name, type)                                                    \
+    class PYBIND11_EXPORT_EXCEPTION name : public builtin_exception {                             \
+    public:                                                                                       \
+        using builtin_exception::builtin_exception;                                               \
+        name() : name("") {}                                                                      \
+        void set_error() const override { PyErr_SetString(type, what()); }                        \
     };
 
 PYBIND11_RUNTIME_EXCEPTION(stop_iteration, PyExc_StopIteration)
@@ -873,13 +987,20 @@ PYBIND11_RUNTIME_EXCEPTION(type_error, PyExc_TypeError)
 PYBIND11_RUNTIME_EXCEPTION(buffer_error, PyExc_BufferError)
 PYBIND11_RUNTIME_EXCEPTION(import_error, PyExc_ImportError)
 PYBIND11_RUNTIME_EXCEPTION(attribute_error, PyExc_AttributeError)
-PYBIND11_RUNTIME_EXCEPTION(cast_error, PyExc_RuntimeError) /// Thrown when pybind11::cast or handle::call fail due to a type casting error
+PYBIND11_RUNTIME_EXCEPTION(cast_error,
+                           PyExc_RuntimeError) /// Thrown when pybind11::cast or handle::call fail
+                                               /// due to a type casting error
 PYBIND11_RUNTIME_EXCEPTION(reference_cast_error, PyExc_RuntimeError) /// Used internally
 
-[[noreturn]] PYBIND11_NOINLINE void pybind11_fail(const char *reason) { throw std::runtime_error(reason); }
-[[noreturn]] PYBIND11_NOINLINE void pybind11_fail(const std::string &reason) { throw std::runtime_error(reason); }
+[[noreturn]] PYBIND11_NOINLINE void pybind11_fail(const char *reason) {
+    throw std::runtime_error(reason);
+}
+[[noreturn]] PYBIND11_NOINLINE void pybind11_fail(const std::string &reason) {
+    throw std::runtime_error(reason);
+}
 
-template <typename T, typename SFINAE = void> struct format_descriptor { };
+template <typename T, typename SFINAE = void>
+struct format_descriptor {};
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 // Returns the index of the given type in the type char array below, and in the list in numpy.h
@@ -887,25 +1008,38 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 // complex float,double,long double.  Note that the long double types only participate when long
 // double is actually longer than double (it isn't under MSVC).
 // NB: not only the string below but also complex.h and numpy.h rely on this order.
-template <typename T, typename SFINAE = void> struct is_fmt_numeric { static constexpr bool value = false; };
-template <typename T> struct is_fmt_numeric<T, enable_if_t<std::is_arithmetic<T>::value>> {
+template <typename T, typename SFINAE = void>
+struct is_fmt_numeric {
+    static constexpr bool value = false;
+};
+template <typename T>
+struct is_fmt_numeric<T, enable_if_t<std::is_arithmetic<T>::value>> {
     static constexpr bool value = true;
-    static constexpr int index = std::is_same<T, bool>::value ? 0 : 1 + (
-        std::is_integral<T>::value ? detail::log2(sizeof(T))*2 + std::is_unsigned<T>::value : 8 + (
-        std::is_same<T, double>::value ? 1 : std::is_same<T, long double>::value ? 2 : 0));
+    static constexpr int index
+        = std::is_same<T, bool>::value
+              ? 0
+              : 1
+                    + (std::is_integral<T>::value
+                           ? detail::log2(sizeof(T)) * 2 + std::is_unsigned<T>::value
+                           : 8
+                                 + (std::is_same<T, double>::value        ? 1
+                                    : std::is_same<T, long double>::value ? 2
+                                                                          : 0));
 };
 PYBIND11_NAMESPACE_END(detail)
 
-template <typename T> struct format_descriptor<T, detail::enable_if_t<std::is_arithmetic<T>::value>> {
+template <typename T>
+struct format_descriptor<T, detail::enable_if_t<std::is_arithmetic<T>::value>> {
     static constexpr const char c = "?bBhHiIqQfdg"[detail::is_fmt_numeric<T>::index];
-    static constexpr const char value[2] = { c, '\0' };
+    static constexpr const char value[2] = {c, '\0'};
     static std::string format() { return std::string(1, c); }
 };
 
 #if !defined(PYBIND11_CPP17)
 
-template <typename T> constexpr const char format_descriptor<
-    T, detail::enable_if_t<std::is_arithmetic<T>::value>>::value[2];
+template <typename T>
+constexpr const char
+    format_descriptor<T, detail::enable_if_t<std::is_arithmetic<T>::value>>::value[2];
 
 #endif
 
@@ -917,7 +1051,10 @@ struct error_scope {
 };
 
 /// Dummy destructor wrapper that can be used to expose classes with a private destructor
-struct nodelete { template <typename T> void operator()(T*) { } };
+struct nodelete {
+    template <typename T>
+    void operator()(T *) {}
+};
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 template <typename... Args>
@@ -926,22 +1063,27 @@ struct overload_cast_impl {
     constexpr overload_cast_impl() {}
 
     template <typename Return>
-    constexpr auto operator()(Return (*pf)(Args...)) const noexcept
-                              -> decltype(pf) { return pf; }
+    constexpr auto operator()(Return (*pf)(Args...)) const noexcept -> decltype(pf) {
+        return pf;
+    }
 
     template <typename Return, typename Class>
     constexpr auto operator()(Return (Class::*pmf)(Args...), std::false_type = {}) const noexcept
-                              -> decltype(pmf) { return pmf; }
+        -> decltype(pmf) {
+        return pmf;
+    }
 
     template <typename Return, typename Class>
     constexpr auto operator()(Return (Class::*pmf)(Args...) const, std::true_type) const noexcept
-                              -> decltype(pmf) { return pmf; }
+        -> decltype(pmf) {
+        return pmf;
+    }
 };
 PYBIND11_NAMESPACE_END(detail)
 
 // overload_cast requires variable templates: C++14
 #if defined(PYBIND11_CPP14)
-#define PYBIND11_OVERLOAD_CAST 1
+#    define PYBIND11_OVERLOAD_CAST 1
 /// Syntax sugar for resolving overloaded function pointers:
 ///  - regular: static_cast<Return (Class::*)(Arg0, Arg1, Arg2)>(&Class::func)
 ///  - sweet:   overload_cast<Arg0, Arg1, Arg2>(&Class::func)
@@ -956,7 +1098,8 @@ static constexpr detail::overload_cast_impl<Args...> overload_cast = {};
 static constexpr auto const_ = std::true_type{};
 
 #if !defined(PYBIND11_CPP14) // no overload_cast: providing something that static_assert-fails:
-template <typename... Args> struct overload_cast {
+template <typename... Args>
+struct overload_cast {
     static_assert(detail::deferred_t<std::false_type, Args...>::value,
                   "pybind11::overload_cast<...> requires compiling in C++14 mode");
 };
@@ -970,26 +1113,31 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 template <typename T>
 class any_container {
     std::vector<T> v;
+
 public:
     any_container() = default;
 
     // Can construct from a pair of iterators
     template <typename It, typename = enable_if_t<is_input_iterator<It>::value>>
-    any_container(It first, It last) : v(first, last) { }
-
-    // Implicit conversion constructor from any arbitrary container type with values convertible to T
-    template <typename Container, typename = enable_if_t<std::is_convertible<decltype(*std::begin(std::declval<const Container &>())), T>::value>>
+    any_container(It first, It last) : v(first, last) {}
+
+    // Implicit conversion constructor from any arbitrary container type with values convertible to
+    // T
+    template <typename Container,
+              typename = enable_if_t<
+                  std::is_convertible<decltype(*std::begin(std::declval<const Container &>())),
+                                      T>::value>>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    any_container(const Container &c) : any_container(std::begin(c), std::end(c)) { }
+    any_container(const Container &c) : any_container(std::begin(c), std::end(c)) {}
 
-    // initializer_list's aren't deducible, so don't get matched by the above template; we need this
-    // to explicitly allow implicit conversion from one:
+    // initializer_list's aren't deducible, so don't get matched by the above template; we need
+    // this to explicitly allow implicit conversion from one:
     template <typename TIn, typename = enable_if_t<std::is_convertible<TIn, T>::value>>
-    any_container(const std::initializer_list<TIn> &c) : any_container(c.begin(), c.end()) { }
+    any_container(const std::initializer_list<TIn> &c) : any_container(c.begin(), c.end()) {}
 
     // Avoid copying if given an rvalue vector of the correct type.
     // NOLINTNEXTLINE(google-explicit-constructor)
-    any_container(std::vector<T> &&v) : v(std::move(v)) { }
+    any_container(std::vector<T> &&v) : v(std::move(v)) {}
 
     // Moves the vector out of an rvalue any_container
     // NOLINTNEXTLINE(google-explicit-constructor)
@@ -1005,10 +1153,11 @@ class any_container {
 };
 
 // Forward-declaration; see detail/class.h
-std::string get_fully_qualified_tp_name(PyTypeObject*);
+std::string get_fully_qualified_tp_name(PyTypeObject *);
 
 template <typename T>
-inline static std::shared_ptr<T> try_get_shared_from_this(std::enable_shared_from_this<T> *holder_value_ptr) {
+inline static std::shared_ptr<T>
+try_get_shared_from_this(std::enable_shared_from_this<T> *holder_value_ptr) {
 // Pre C++17, this code path exploits undefined behavior, but is known to work on many platforms.
 // Use at your own risk!
 // See also https://en.cppreference.com/w/cpp/memory/enable_shared_from_this, and in particular
@@ -1018,8 +1167,7 @@ inline static std::shared_ptr<T> try_get_shared_from_this(std::enable_shared_fro
 #else
     try {
         return holder_value_ptr->shared_from_this();
-    }
-    catch (const std::bad_weak_ptr &) {
+    } catch (const std::bad_weak_ptr &) {
         return nullptr;
     }
 #endif
@@ -1030,7 +1178,9 @@ template <typename... Args>
 #if defined(_MSC_VER) && _MSC_VER >= 1910 && _MSC_VER < 1920 // MSVC 2017
 constexpr
 #endif
-inline void silence_unused_warnings(Args &&...) {}
+    inline void
+    silence_unused_warnings(Args &&...) {
+}
 
 // MSVC warning C4100: Unreferenced formal parameter
 #if defined(_MSC_VER) && _MSC_VER <= 1916
@@ -1042,7 +1192,7 @@ inline void silence_unused_warnings(Args &&...) {}
 
 // GCC -Wunused-but-set-parameter  All GCC versions (as of July 2021).
 #if defined(__GNUG__) && !defined(__clang__) && !defined(__INTEL_COMPILER)
-#    define PYBIND11_WORKAROUND_INCORRECT_GCC_UNUSED_BUT_SET_PARAMETER(...)                   \
+#    define PYBIND11_WORKAROUND_INCORRECT_GCC_UNUSED_BUT_SET_PARAMETER(...)                       \
         detail::silence_unused_warnings(__VA_ARGS__)
 #else
 #    define PYBIND11_WORKAROUND_INCORRECT_GCC_UNUSED_BUT_SET_PARAMETER(...)
diff --git a/include/pybind11/detail/descr.h b/include/pybind11/detail/descr.h
index 0f93e06b21..e7a5e2c145 100644
--- a/include/pybind11/detail/descr.h
+++ b/include/pybind11/detail/descr.h
@@ -15,9 +15,9 @@ PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 #if !defined(_MSC_VER)
-#  define PYBIND11_DESCR_CONSTEXPR static constexpr
+#    define PYBIND11_DESCR_CONSTEXPR static constexpr
 #else
-#  define PYBIND11_DESCR_CONSTEXPR const
+#    define PYBIND11_DESCR_CONSTEXPR const
 #endif
 
 /* Concatenate type signatures at compile time */
@@ -27,14 +27,14 @@ struct descr {
 
     constexpr descr() = default;
     // NOLINTNEXTLINE(google-explicit-constructor)
-    constexpr descr(char const (&s)[N+1]) : descr(s, make_index_sequence<N>()) { }
+    constexpr descr(char const (&s)[N + 1]) : descr(s, make_index_sequence<N>()) {}
 
     template <size_t... Is>
-    constexpr descr(char const (&s)[N+1], index_sequence<Is...>) : text{s[Is]..., '\0'} { }
+    constexpr descr(char const (&s)[N + 1], index_sequence<Is...>) : text{s[Is]..., '\0'} {}
 
     template <typename... Chars>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    constexpr descr(char c, Chars... cs) : text{c, static_cast<char>(cs)..., '\0'} { }
+    constexpr descr(char c, Chars... cs) : text{c, static_cast<char>(cs)..., '\0'} {}
 
     static constexpr std::array<const std::type_info *, sizeof...(Ts) + 1> types() {
         return {{&typeid(Ts)..., nullptr}};
@@ -42,81 +42,106 @@ struct descr {
 };
 
 template <size_t N1, size_t N2, typename... Ts1, typename... Ts2, size_t... Is1, size_t... Is2>
-constexpr descr<N1 + N2, Ts1..., Ts2...> plus_impl(const descr<N1, Ts1...> &a, const descr<N2, Ts2...> &b,
-                                                   index_sequence<Is1...>, index_sequence<Is2...>) {
+constexpr descr<N1 + N2, Ts1..., Ts2...> plus_impl(const descr<N1, Ts1...> &a,
+                                                   const descr<N2, Ts2...> &b,
+                                                   index_sequence<Is1...>,
+                                                   index_sequence<Is2...>) {
     PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(b);
     return {a.text[Is1]..., b.text[Is2]...};
 }
 
 template <size_t N1, size_t N2, typename... Ts1, typename... Ts2>
-constexpr descr<N1 + N2, Ts1..., Ts2...> operator+(const descr<N1, Ts1...> &a, const descr<N2, Ts2...> &b) {
+constexpr descr<N1 + N2, Ts1..., Ts2...> operator+(const descr<N1, Ts1...> &a,
+                                                   const descr<N2, Ts2...> &b) {
     return plus_impl(a, b, make_index_sequence<N1>(), make_index_sequence<N2>());
 }
 
 template <size_t N>
-constexpr descr<N - 1> const_name(char const(&text)[N]) { return descr<N - 1>(text); }
-constexpr descr<0> const_name(char const(&)[1]) { return {}; }
+constexpr descr<N - 1> const_name(char const (&text)[N]) {
+    return descr<N - 1>(text);
+}
+constexpr descr<0> const_name(char const (&)[1]) { return {}; }
 
-template <size_t Rem, size_t... Digits> struct int_to_str : int_to_str<Rem/10, Rem%10, Digits...> { };
-template <size_t...Digits> struct int_to_str<0, Digits...> {
+template <size_t Rem, size_t... Digits>
+struct int_to_str : int_to_str<Rem / 10, Rem % 10, Digits...> {};
+template <size_t... Digits>
+struct int_to_str<0, Digits...> {
     // WARNING: This only works with C++17 or higher.
     static constexpr auto digits = descr<sizeof...(Digits)>(('0' + Digits)...);
 };
 
 // Ternary description (like std::conditional)
 template <bool B, size_t N1, size_t N2>
-constexpr enable_if_t<B, descr<N1 - 1>> const_name(char const(&text1)[N1], char const(&)[N2]) {
+constexpr enable_if_t<B, descr<N1 - 1>> const_name(char const (&text1)[N1], char const (&)[N2]) {
     return const_name(text1);
 }
 template <bool B, size_t N1, size_t N2>
-constexpr enable_if_t<!B, descr<N2 - 1>> const_name(char const(&)[N1], char const(&text2)[N2]) {
+constexpr enable_if_t<!B, descr<N2 - 1>> const_name(char const (&)[N1], char const (&text2)[N2]) {
     return const_name(text2);
 }
 
 template <bool B, typename T1, typename T2>
-constexpr enable_if_t<B, T1> const_name(const T1 &d, const T2 &) { return d; }
+constexpr enable_if_t<B, T1> const_name(const T1 &d, const T2 &) {
+    return d;
+}
 template <bool B, typename T1, typename T2>
-constexpr enable_if_t<!B, T2> const_name(const T1 &, const T2 &d) { return d; }
+constexpr enable_if_t<!B, T2> const_name(const T1 &, const T2 &d) {
+    return d;
+}
 
 template <size_t Size>
 auto constexpr const_name() -> remove_cv_t<decltype(int_to_str<Size / 10, Size % 10>::digits)> {
     return int_to_str<Size / 10, Size % 10>::digits;
 }
 
-template <typename Type> constexpr descr<1, Type> const_name() { return {'%'}; }
+template <typename Type>
+constexpr descr<1, Type> const_name() {
+    return {'%'};
+}
 
 // If "_" is defined as a macro, py::detail::_ cannot be provided.
 // It is therefore best to use py::detail::const_name universally.
 // This block is for backward compatibility only.
 // (The const_name code is repeated to avoid introducing a "_" #define ourselves.)
 #ifndef _
-#define PYBIND11_DETAIL_UNDERSCORE_BACKWARD_COMPATIBILITY
+#    define PYBIND11_DETAIL_UNDERSCORE_BACKWARD_COMPATIBILITY
 template <size_t N>
-constexpr descr<N-1> _(char const(&text)[N]) { return const_name<N>(text); }
+constexpr descr<N - 1> _(char const (&text)[N]) {
+    return const_name<N>(text);
+}
 template <bool B, size_t N1, size_t N2>
-constexpr enable_if_t<B, descr<N1 - 1>> _(char const(&text1)[N1], char const(&text2)[N2]) {
-    return const_name<B,N1,N2>(text1, text2);
+constexpr enable_if_t<B, descr<N1 - 1>> _(char const (&text1)[N1], char const (&text2)[N2]) {
+    return const_name<B, N1, N2>(text1, text2);
 }
 template <bool B, size_t N1, size_t N2>
-constexpr enable_if_t<!B, descr<N2 - 1>> _(char const(&text1)[N1], char const(&text2)[N2]) {
-    return const_name<B,N1,N2>(text1, text2);
+constexpr enable_if_t<!B, descr<N2 - 1>> _(char const (&text1)[N1], char const (&text2)[N2]) {
+    return const_name<B, N1, N2>(text1, text2);
 }
 template <bool B, typename T1, typename T2>
-constexpr enable_if_t<B, T1> _(const T1 &d1, const T2 &d2) { return const_name<B,T1,T2>(d1, d2); }
+constexpr enable_if_t<B, T1> _(const T1 &d1, const T2 &d2) {
+    return const_name<B, T1, T2>(d1, d2);
+}
 template <bool B, typename T1, typename T2>
-constexpr enable_if_t<!B, T2> _(const T1 &d1, const T2 &d2) { return const_name<B,T1,T2>(d1, d2); }
+constexpr enable_if_t<!B, T2> _(const T1 &d1, const T2 &d2) {
+    return const_name<B, T1, T2>(d1, d2);
+}
 
 template <size_t Size>
 auto constexpr _() -> remove_cv_t<decltype(int_to_str<Size / 10, Size % 10>::digits)> {
     return const_name<Size>();
 }
-template <typename Type> constexpr descr<1, Type> _() { return const_name<Type>(); }
-#endif  // #ifndef _
+template <typename Type>
+constexpr descr<1, Type> _() {
+    return const_name<Type>();
+}
+#endif // #ifndef _
 
 constexpr descr<0> concat() { return {}; }
 
 template <size_t N, typename... Ts>
-constexpr descr<N, Ts...> concat(const descr<N, Ts...> &descr) { return descr; }
+constexpr descr<N, Ts...> concat(const descr<N, Ts...> &descr) {
+    return descr;
+}
 
 template <size_t N, typename... Ts, typename... Args>
 constexpr auto concat(const descr<N, Ts...> &d, const Args &...args)
diff --git a/include/pybind11/detail/init.h b/include/pybind11/detail/init.h
index eaaad5a07a..34ae8f4c67 100644
--- a/include/pybind11/detail/init.h
+++ b/include/pybind11/detail/init.h
@@ -22,7 +22,8 @@ class type_caster<value_and_holder> {
         return true;
     }
 
-    template <typename> using cast_op_type = value_and_holder &;
+    template <typename>
+    using cast_op_type = value_and_holder &;
     explicit operator value_and_holder &() { return *value; }
     static constexpr auto name = const_name<value_and_holder>();
 
@@ -33,15 +34,20 @@ class type_caster<value_and_holder> {
 PYBIND11_NAMESPACE_BEGIN(initimpl)
 
 inline void no_nullptr(void *ptr) {
-    if (!ptr) throw type_error("pybind11::init(): factory function returned nullptr");
+    if (!ptr)
+        throw type_error("pybind11::init(): factory function returned nullptr");
 }
 
 // Implementing functions for all forms of py::init<...> and py::init(...)
-template <typename Class> using Cpp = typename Class::type;
-template <typename Class> using Alias = typename Class::type_alias;
-template <typename Class> using Holder = typename Class::holder_type;
+template <typename Class>
+using Cpp = typename Class::type;
+template <typename Class>
+using Alias = typename Class::type_alias;
+template <typename Class>
+using Holder = typename Class::holder_type;
 
-template <typename Class> using is_alias_constructible = std::is_constructible<Alias<Class>, Cpp<Class> &&>;
+template <typename Class>
+using is_alias_constructible = std::is_constructible<Alias<Class>, Cpp<Class> &&>;
 
 // Takes a Cpp pointer and returns true if it actually is a polymorphic Alias instance.
 template <typename Class, enable_if_t<Class::has_alias, int> = 0>
@@ -50,17 +56,27 @@ bool is_alias(Cpp<Class> *ptr) {
 }
 // Failing fallback version of the above for a no-alias class (always returns false)
 template <typename /*Class*/>
-constexpr bool is_alias(void *) { return false; }
+constexpr bool is_alias(void *) {
+    return false;
+}
 
 // Constructs and returns a new object; if the given arguments don't map to a constructor, we fall
 // back to brace aggregate initiailization so that for aggregate initialization can be used with
 // py::init, e.g.  `py::init<int, int>` to initialize a `struct T { int a; int b; }`.  For
 // non-aggregate types, we need to use an ordinary T(...) constructor (invoking as `T{...}` usually
 // works, but will not do the expected thing when `T` has an `initializer_list<T>` constructor).
-template <typename Class, typename... Args, detail::enable_if_t<std::is_constructible<Class, Args...>::value, int> = 0>
-inline Class *construct_or_initialize(Args &&...args) { return new Class(std::forward<Args>(args)...); }
-template <typename Class, typename... Args, detail::enable_if_t<!std::is_constructible<Class, Args...>::value, int> = 0>
-inline Class *construct_or_initialize(Args &&...args) { return new Class{std::forward<Args>(args)...}; }
+template <typename Class,
+          typename... Args,
+          detail::enable_if_t<std::is_constructible<Class, Args...>::value, int> = 0>
+inline Class *construct_or_initialize(Args &&...args) {
+    return new Class(std::forward<Args>(args)...);
+}
+template <typename Class,
+          typename... Args,
+          detail::enable_if_t<!std::is_constructible<Class, Args...>::value, int> = 0>
+inline Class *construct_or_initialize(Args &&...args) {
+    return new Class{std::forward<Args>(args)...};
+}
 
 // Attempts to constructs an alias using a `Alias(Cpp &&)` constructor.  This allows types with
 // an alias to provide only a single Cpp factory function as long as the Alias can be
@@ -69,12 +85,14 @@ inline Class *construct_or_initialize(Args &&...args) { return new Class{std::fo
 // inherit all the base class constructors.
 template <typename Class>
 void construct_alias_from_cpp(std::true_type /*is_alias_constructible*/,
-                              value_and_holder &v_h, Cpp<Class> &&base) {
+                              value_and_holder &v_h,
+                              Cpp<Class> &&base) {
     v_h.value_ptr() = new Alias<Class>(std::move(base));
 }
 template <typename Class>
 [[noreturn]] void construct_alias_from_cpp(std::false_type /*!is_alias_constructible*/,
-                                           value_and_holder &, Cpp<Class> &&) {
+                                           value_and_holder &,
+                                           Cpp<Class> &&) {
     throw type_error("pybind11::init(): unable to convert returned instance to required "
                      "alias class: no `Alias<Class>(Class &&)` constructor available");
 }
@@ -84,8 +102,8 @@ template <typename Class>
 template <typename Class>
 void construct(...) {
     static_assert(!std::is_same<Class, Class>::value /* always false */,
-            "pybind11::init(): init function must return a compatible pointer, "
-            "holder, or value");
+                  "pybind11::init(): init function must return a compatible pointer, "
+                  "holder, or value");
 }
 
 // Pointer return v1: the factory function returns a class pointer for a registered class.
@@ -106,7 +124,7 @@ void construct(value_and_holder &v_h, Cpp<Class> *ptr, bool need_alias) {
         // the holder and destruction happens when we leave the C++ scope, and the holder
         // class gets to handle the destruction however it likes.
         v_h.value_ptr() = ptr;
-        v_h.set_instance_registered(true); // To prevent init_instance from registering it
+        v_h.set_instance_registered(true);          // To prevent init_instance from registering it
         v_h.type->init_instance(v_h.inst, nullptr); // Set up the holder
         Holder<Class> temp_holder(std::move(v_h.holder<Holder<Class>>())); // Steal the holder
         v_h.type->dealloc(v_h); // Destroys the moved-out holder remains, resets value ptr to null
@@ -129,7 +147,8 @@ void construct(value_and_holder &v_h, Alias<Class> *alias_ptr, bool) {
 
 // Holder return: copy its pointer, and move or copy the returned holder into the new instance's
 // holder.  This also handles types like std::shared_ptr<T> and std::unique_ptr<T> where T is a
-// derived type (through those holder's implicit conversion from derived class holder constructors).
+// derived type (through those holder's implicit conversion from derived class holder
+// constructors).
 template <typename Class>
 void construct(value_and_holder &v_h, Holder<Class> holder, bool need_alias) {
     PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(need_alias);
@@ -152,7 +171,7 @@ template <typename Class>
 void construct(value_and_holder &v_h, Cpp<Class> &&result, bool need_alias) {
     PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(need_alias);
     static_assert(std::is_move_constructible<Cpp<Class>>::value,
-        "pybind11::init() return-by-value factory function requires a movable class");
+                  "pybind11::init() return-by-value factory function requires a movable class");
     if (PYBIND11_SILENCE_MSVC_C4127(Class::has_alias) && need_alias)
         construct_alias_from_cpp<Class>(is_alias_constructible<Class>{}, v_h, std::move(result));
     else
@@ -164,7 +183,8 @@ void construct(value_and_holder &v_h, Cpp<Class> &&result, bool need_alias) {
 // cases where Alias initialization is always desired.
 template <typename Class>
 void construct(value_and_holder &v_h, Alias<Class> &&result, bool) {
-    static_assert(std::is_move_constructible<Alias<Class>>::value,
+    static_assert(
+        std::is_move_constructible<Alias<Class>>::value,
         "pybind11::init() return-by-alias-value factory function requires a movable alias class");
     v_h.value_ptr() = new Alias<Class>(std::move(result));
 }
@@ -173,48 +193,75 @@ void construct(value_and_holder &v_h, Alias<Class> &&result, bool) {
 template <typename... Args>
 struct constructor {
     template <typename Class, typename... Extra, enable_if_t<!Class::has_alias, int> = 0>
-    static void execute(Class &cl, const Extra&... extra) {
-        cl.def("__init__", [](value_and_holder &v_h, Args... args) {
-            v_h.value_ptr() = construct_or_initialize<Cpp<Class>>(std::forward<Args>(args)...);
-        }, is_new_style_constructor(), extra...);
+    static void execute(Class &cl, const Extra &...extra) {
+        cl.def(
+            "__init__",
+            [](value_and_holder &v_h, Args... args) {
+                v_h.value_ptr() = construct_or_initialize<Cpp<Class>>(std::forward<Args>(args)...);
+            },
+            is_new_style_constructor(),
+            extra...);
     }
 
-    template <typename Class, typename... Extra,
-              enable_if_t<Class::has_alias &&
-                          std::is_constructible<Cpp<Class>, Args...>::value, int> = 0>
-    static void execute(Class &cl, const Extra&... extra) {
-        cl.def("__init__", [](value_and_holder &v_h, Args... args) {
-            if (Py_TYPE(v_h.inst) == v_h.type->type)
-                v_h.value_ptr() = construct_or_initialize<Cpp<Class>>(std::forward<Args>(args)...);
-            else
-                v_h.value_ptr() = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
-        }, is_new_style_constructor(), extra...);
+    template <typename Class,
+              typename... Extra,
+              enable_if_t<Class::has_alias && std::is_constructible<Cpp<Class>, Args...>::value,
+                          int> = 0>
+    static void execute(Class &cl, const Extra &...extra) {
+        cl.def(
+            "__init__",
+            [](value_and_holder &v_h, Args... args) {
+                if (Py_TYPE(v_h.inst) == v_h.type->type)
+                    v_h.value_ptr()
+                        = construct_or_initialize<Cpp<Class>>(std::forward<Args>(args)...);
+                else
+                    v_h.value_ptr()
+                        = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
+            },
+            is_new_style_constructor(),
+            extra...);
     }
 
-    template <typename Class, typename... Extra,
-              enable_if_t<Class::has_alias &&
-                          !std::is_constructible<Cpp<Class>, Args...>::value, int> = 0>
-    static void execute(Class &cl, const Extra&... extra) {
-        cl.def("__init__", [](value_and_holder &v_h, Args... args) {
-            v_h.value_ptr() = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
-        }, is_new_style_constructor(), extra...);
+    template <typename Class,
+              typename... Extra,
+              enable_if_t<Class::has_alias && !std::is_constructible<Cpp<Class>, Args...>::value,
+                          int> = 0>
+    static void execute(Class &cl, const Extra &...extra) {
+        cl.def(
+            "__init__",
+            [](value_and_holder &v_h, Args... args) {
+                v_h.value_ptr()
+                    = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
+            },
+            is_new_style_constructor(),
+            extra...);
     }
 };
 
 // Implementing class for py::init_alias<...>()
-template <typename... Args> struct alias_constructor {
-    template <typename Class, typename... Extra,
-              enable_if_t<Class::has_alias && std::is_constructible<Alias<Class>, Args...>::value, int> = 0>
-    static void execute(Class &cl, const Extra&... extra) {
-        cl.def("__init__", [](value_and_holder &v_h, Args... args) {
-            v_h.value_ptr() = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
-        }, is_new_style_constructor(), extra...);
+template <typename... Args>
+struct alias_constructor {
+    template <typename Class,
+              typename... Extra,
+              enable_if_t<Class::has_alias && std::is_constructible<Alias<Class>, Args...>::value,
+                          int> = 0>
+    static void execute(Class &cl, const Extra &...extra) {
+        cl.def(
+            "__init__",
+            [](value_and_holder &v_h, Args... args) {
+                v_h.value_ptr()
+                    = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
+            },
+            is_new_style_constructor(),
+            extra...);
     }
 };
 
 // Implementation class for py::init(Func) and py::init(Func, AliasFunc)
-template <typename CFunc, typename AFunc = void_type (*)(),
-          typename = function_signature_t<CFunc>, typename = function_signature_t<AFunc>>
+template <typename CFunc,
+          typename AFunc = void_type (*)(),
+          typename = function_signature_t<CFunc>,
+          typename = function_signature_t<AFunc>>
 struct factory;
 
 // Specialization for py::init(Func)
@@ -232,22 +279,32 @@ struct factory<Func, void_type (*)(), Return(Args...)> {
     // instance, or the alias needs to be constructible from a `Class &&` argument.
     template <typename Class, typename... Extra>
     void execute(Class &cl, const Extra &...extra) && {
-        #if defined(PYBIND11_CPP14)
-        cl.def("__init__", [func = std::move(class_factory)]
-        #else
+#if defined(PYBIND11_CPP14)
+        cl.def(
+            "__init__",
+            [func = std::move(class_factory)]
+#else
         auto &func = class_factory;
-        cl.def("__init__", [func]
-        #endif
-        (value_and_holder &v_h, Args... args) {
-            construct<Class>(v_h, func(std::forward<Args>(args)...),
-                             Py_TYPE(v_h.inst) != v_h.type->type);
-        }, is_new_style_constructor(), extra...);
+        cl.def(
+            "__init__",
+            [func]
+#endif
+            (value_and_holder &v_h, Args... args) {
+                construct<Class>(
+                    v_h, func(std::forward<Args>(args)...), Py_TYPE(v_h.inst) != v_h.type->type);
+            },
+            is_new_style_constructor(),
+            extra...);
     }
 };
 
 // Specialization for py::init(Func, AliasFunc)
-template <typename CFunc, typename AFunc,
-          typename CReturn, typename... CArgs, typename AReturn, typename... AArgs>
+template <typename CFunc,
+          typename AFunc,
+          typename CReturn,
+          typename... CArgs,
+          typename AReturn,
+          typename... AArgs>
 struct factory<CFunc, AFunc, CReturn(CArgs...), AReturn(AArgs...)> {
     static_assert(sizeof...(CArgs) == sizeof...(AArgs),
                   "pybind11::init(class_factory, alias_factory): class and alias factories "
@@ -260,29 +317,36 @@ struct factory<CFunc, AFunc, CReturn(CArgs...), AReturn(AArgs...)> {
     remove_reference_t<AFunc> alias_factory;
 
     factory(CFunc &&c, AFunc &&a)
-        : class_factory(std::forward<CFunc>(c)), alias_factory(std::forward<AFunc>(a)) { }
+        : class_factory(std::forward<CFunc>(c)), alias_factory(std::forward<AFunc>(a)) {}
 
     // The class factory is called when the `self` type passed to `__init__` is the direct
     // class (i.e. not inherited), the alias factory when `self` is a Python-side subtype.
     template <typename Class, typename... Extra>
-    void execute(Class &cl, const Extra&... extra) && {
-        static_assert(Class::has_alias, "The two-argument version of `py::init()` can "
-                                        "only be used if the class has an alias");
-        #if defined(PYBIND11_CPP14)
-        cl.def("__init__", [class_func = std::move(class_factory), alias_func = std::move(alias_factory)]
-        #else
+    void execute(Class &cl, const Extra &...extra) && {
+        static_assert(Class::has_alias,
+                      "The two-argument version of `py::init()` can "
+                      "only be used if the class has an alias");
+#if defined(PYBIND11_CPP14)
+        cl.def(
+            "__init__",
+            [class_func = std::move(class_factory), alias_func = std::move(alias_factory)]
+#else
         auto &class_func = class_factory;
         auto &alias_func = alias_factory;
-        cl.def("__init__", [class_func, alias_func]
-        #endif
-        (value_and_holder &v_h, CArgs... args) {
-            if (Py_TYPE(v_h.inst) == v_h.type->type)
-                // If the instance type equals the registered type we don't have inheritance, so
-                // don't need the alias and can construct using the class function:
-                construct<Class>(v_h, class_func(std::forward<CArgs>(args)...), false);
-            else
-                construct<Class>(v_h, alias_func(std::forward<CArgs>(args)...), true);
-        }, is_new_style_constructor(), extra...);
+        cl.def(
+            "__init__",
+            [class_func, alias_func]
+#endif
+            (value_and_holder &v_h, CArgs... args) {
+                if (Py_TYPE(v_h.inst) == v_h.type->type)
+                    // If the instance type equals the registered type we don't have inheritance,
+                    // so don't need the alias and can construct using the class function:
+                    construct<Class>(v_h, class_func(std::forward<CArgs>(args)...), false);
+                else
+                    construct<Class>(v_h, alias_func(std::forward<CArgs>(args)...), true);
+            },
+            is_new_style_constructor(),
+            extra...);
     }
 };
 
@@ -293,7 +357,9 @@ void setstate(value_and_holder &v_h, T &&result, bool need_alias) {
 }
 
 /// Set both the C++ and Python states
-template <typename Class, typename T, typename O,
+template <typename Class,
+          typename T,
+          typename O,
           enable_if_t<std::is_convertible<O, handle>::value, int> = 0>
 void setstate(value_and_holder &v_h, std::pair<T, O> &&result, bool need_alias) {
     construct<Class>(v_h, std::move(result.first), need_alias);
@@ -307,12 +373,18 @@ void setstate(value_and_holder &v_h, std::pair<T, O> &&result, bool need_alias)
 }
 
 /// Implementation for py::pickle(GetState, SetState)
-template <typename Get, typename Set,
-          typename = function_signature_t<Get>, typename = function_signature_t<Set>>
+template <typename Get,
+          typename Set,
+          typename = function_signature_t<Get>,
+          typename = function_signature_t<Set>>
 struct pickle_factory;
 
-template <typename Get, typename Set,
-          typename RetState, typename Self, typename NewInstance, typename ArgState>
+template <typename Get,
+          typename Set,
+          typename RetState,
+          typename Self,
+          typename NewInstance,
+          typename ArgState>
 struct pickle_factory<Get, Set, RetState(Self), NewInstance(ArgState)> {
     static_assert(std::is_same<intrinsic_t<RetState>, intrinsic_t<ArgState>>::value,
                   "The type returned by `__getstate__` must be the same "
@@ -321,23 +393,28 @@ struct pickle_factory<Get, Set, RetState(Self), NewInstance(ArgState)> {
     remove_reference_t<Get> get;
     remove_reference_t<Set> set;
 
-    pickle_factory(Get get, Set set)
-        : get(std::forward<Get>(get)), set(std::forward<Set>(set)) { }
+    pickle_factory(Get get, Set set) : get(std::forward<Get>(get)), set(std::forward<Set>(set)) {}
 
     template <typename Class, typename... Extra>
     void execute(Class &cl, const Extra &...extra) && {
         cl.def("__getstate__", std::move(get));
 
 #if defined(PYBIND11_CPP14)
-        cl.def("__setstate__", [func = std::move(set)]
+        cl.def(
+            "__setstate__",
+            [func = std::move(set)]
 #else
         auto &func = set;
-        cl.def("__setstate__", [func]
+        cl.def(
+            "__setstate__",
+            [func]
 #endif
-        (value_and_holder &v_h, ArgState state) {
-            setstate<Class>(v_h, func(std::forward<ArgState>(state)),
-                            Py_TYPE(v_h.inst) != v_h.type->type);
-        }, is_new_style_constructor(), extra...);
+            (value_and_holder &v_h, ArgState state) {
+                setstate<Class>(
+                    v_h, func(std::forward<ArgState>(state)), Py_TYPE(v_h.inst) != v_h.type->type);
+            },
+            is_new_style_constructor(),
+            extra...);
     }
 };
 
diff --git a/include/pybind11/detail/internals.h b/include/pybind11/detail/internals.h
index 9edb9492e2..3db656af75 100644
--- a/include/pybind11/detail/internals.h
+++ b/include/pybind11/detail/internals.h
@@ -10,6 +10,7 @@
 #pragma once
 
 #include "../pytypes.h"
+
 #include <exception>
 
 /// Tracks the `internals` and `type_info` ABI version independent of the main library version.
@@ -135,9 +136,9 @@ template <typename value_type>
 using type_map = std::unordered_map<std::type_index, value_type, type_hash, type_equal_to>;
 
 struct override_hash {
-    inline size_t operator()(const std::pair<const PyObject *, const char *>& v) const {
+    inline size_t operator()(const std::pair<const PyObject *, const char *> &v) const {
         size_t value = std::hash<const void *>()(v.first);
-        value ^= std::hash<const void *>()(v.second) + 0x9e3779b9 + (value<<6) + (value>>2);
+        value ^= std::hash<const void *>()(v.second) + 0x9e3779b9 + (value << 6) + (value >> 2);
         return value;
     }
 };
@@ -147,17 +148,21 @@ struct override_hash {
 /// `PYBIND11_INTERNALS_VERSION` must be incremented.
 struct internals {
     type_map<type_info *> registered_types_cpp; // std::type_index -> pybind11's type information
-    std::unordered_map<PyTypeObject *, std::vector<type_info *>> registered_types_py; // PyTypeObject* -> base type_info(s)
-    std::unordered_multimap<const void *, instance*> registered_instances; // void * -> instance*
-    std::unordered_set<std::pair<const PyObject *, const char *>, override_hash> inactive_override_cache;
+    std::unordered_map<PyTypeObject *, std::vector<type_info *>>
+        registered_types_py; // PyTypeObject* -> base type_info(s)
+    std::unordered_multimap<const void *, instance *> registered_instances; // void * -> instance*
+    std::unordered_set<std::pair<const PyObject *, const char *>, override_hash>
+        inactive_override_cache;
     type_map<std::vector<bool (*)(PyObject *, void *&)>> direct_conversions;
     std::unordered_map<const PyObject *, std::vector<PyObject *>> patients;
     std::forward_list<ExceptionTranslator> registered_exception_translators;
-    std::unordered_map<std::string, void *> shared_data; // Custom data to be shared across extensions
+    std::unordered_map<std::string, void *>
+        shared_data; // Custom data to be shared across extensions
 #if PYBIND11_INTERNALS_VERSION == 4
     std::vector<PyObject *> unused_loader_patient_stack_remove_at_v5;
 #endif
-    std::forward_list<std::string> static_strings; // Stores the std::strings backing detail::c_str()
+    std::forward_list<std::string>
+        static_strings; // Stores the std::strings backing detail::c_str()
     PyTypeObject *static_property_type;
     PyTypeObject *default_metaclass;
     PyObject *instance_base;
@@ -193,8 +198,8 @@ struct type_info {
     void *(*operator_new)(size_t);
     void (*init_instance)(instance *, const void *);
     void (*dealloc)(value_and_holder &v_h);
-    std::vector<PyObject *(*)(PyObject *, PyTypeObject *)> implicit_conversions;
-    std::vector<std::pair<const std::type_info *, void *(*)(void *)>> implicit_casts;
+    std::vector<PyObject *(*) (PyObject *, PyTypeObject *)> implicit_conversions;
+    std::vector<std::pair<const std::type_info *, void *(*) (void *)>> implicit_casts;
     std::vector<bool (*)(PyObject *, void *&)> *direct_conversions;
     buffer_info *(*get_buffer)(PyObject *, void *) = nullptr;
     void *get_buffer_data = nullptr;
@@ -214,67 +219,71 @@ struct type_info {
 
 /// On MSVC, debug and release builds are not ABI-compatible!
 #if defined(_MSC_VER) && defined(_DEBUG)
-#  define PYBIND11_BUILD_TYPE "_debug"
+#    define PYBIND11_BUILD_TYPE "_debug"
 #else
-#  define PYBIND11_BUILD_TYPE ""
+#    define PYBIND11_BUILD_TYPE ""
 #endif
 
 /// Let's assume that different compilers are ABI-incompatible.
 /// A user can manually set this string if they know their
 /// compiler is compatible.
 #ifndef PYBIND11_COMPILER_TYPE
-#  if defined(_MSC_VER)
-#    define PYBIND11_COMPILER_TYPE "_msvc"
-#  elif defined(__INTEL_COMPILER)
-#    define PYBIND11_COMPILER_TYPE "_icc"
-#  elif defined(__clang__)
-#    define PYBIND11_COMPILER_TYPE "_clang"
-#  elif defined(__PGI)
-#    define PYBIND11_COMPILER_TYPE "_pgi"
-#  elif defined(__MINGW32__)
-#    define PYBIND11_COMPILER_TYPE "_mingw"
-#  elif defined(__CYGWIN__)
-#    define PYBIND11_COMPILER_TYPE "_gcc_cygwin"
-#  elif defined(__GNUC__)
-#    define PYBIND11_COMPILER_TYPE "_gcc"
-#  else
-#    define PYBIND11_COMPILER_TYPE "_unknown"
-#  endif
+#    if defined(_MSC_VER)
+#        define PYBIND11_COMPILER_TYPE "_msvc"
+#    elif defined(__INTEL_COMPILER)
+#        define PYBIND11_COMPILER_TYPE "_icc"
+#    elif defined(__clang__)
+#        define PYBIND11_COMPILER_TYPE "_clang"
+#    elif defined(__PGI)
+#        define PYBIND11_COMPILER_TYPE "_pgi"
+#    elif defined(__MINGW32__)
+#        define PYBIND11_COMPILER_TYPE "_mingw"
+#    elif defined(__CYGWIN__)
+#        define PYBIND11_COMPILER_TYPE "_gcc_cygwin"
+#    elif defined(__GNUC__)
+#        define PYBIND11_COMPILER_TYPE "_gcc"
+#    else
+#        define PYBIND11_COMPILER_TYPE "_unknown"
+#    endif
 #endif
 
 /// Also standard libs
 #ifndef PYBIND11_STDLIB
-#  if defined(_LIBCPP_VERSION)
-#    define PYBIND11_STDLIB "_libcpp"
-#  elif defined(__GLIBCXX__) || defined(__GLIBCPP__)
-#    define PYBIND11_STDLIB "_libstdcpp"
-#  else
-#    define PYBIND11_STDLIB ""
-#  endif
+#    if defined(_LIBCPP_VERSION)
+#        define PYBIND11_STDLIB "_libcpp"
+#    elif defined(__GLIBCXX__) || defined(__GLIBCPP__)
+#        define PYBIND11_STDLIB "_libstdcpp"
+#    else
+#        define PYBIND11_STDLIB ""
+#    endif
 #endif
 
 /// On Linux/OSX, changes in __GXX_ABI_VERSION__ indicate ABI incompatibility.
 #ifndef PYBIND11_BUILD_ABI
-#  if defined(__GXX_ABI_VERSION)
-#    define PYBIND11_BUILD_ABI "_cxxabi" PYBIND11_TOSTRING(__GXX_ABI_VERSION)
-#  else
-#    define PYBIND11_BUILD_ABI ""
-#  endif
+#    if defined(__GXX_ABI_VERSION)
+#        define PYBIND11_BUILD_ABI "_cxxabi" PYBIND11_TOSTRING(__GXX_ABI_VERSION)
+#    else
+#        define PYBIND11_BUILD_ABI ""
+#    endif
 #endif
 
 #ifndef PYBIND11_INTERNALS_KIND
-#  if defined(WITH_THREAD)
-#    define PYBIND11_INTERNALS_KIND ""
-#  else
-#    define PYBIND11_INTERNALS_KIND "_without_thread"
-#  endif
+#    if defined(WITH_THREAD)
+#        define PYBIND11_INTERNALS_KIND ""
+#    else
+#        define PYBIND11_INTERNALS_KIND "_without_thread"
+#    endif
 #endif
 
-#define PYBIND11_INTERNALS_ID "__pybind11_internals_v" \
-    PYBIND11_TOSTRING(PYBIND11_INTERNALS_VERSION) PYBIND11_INTERNALS_KIND PYBIND11_COMPILER_TYPE PYBIND11_STDLIB PYBIND11_BUILD_ABI PYBIND11_BUILD_TYPE "__"
+#define PYBIND11_INTERNALS_ID                                                                     \
+    "__pybind11_internals_v" PYBIND11_TOSTRING(PYBIND11_INTERNALS_VERSION)                        \
+        PYBIND11_INTERNALS_KIND PYBIND11_COMPILER_TYPE PYBIND11_STDLIB PYBIND11_BUILD_ABI         \
+            PYBIND11_BUILD_TYPE "__"
 
-#define PYBIND11_MODULE_LOCAL_ID "__pybind11_module_local_v" \
-    PYBIND11_TOSTRING(PYBIND11_INTERNALS_VERSION) PYBIND11_INTERNALS_KIND PYBIND11_COMPILER_TYPE PYBIND11_STDLIB PYBIND11_BUILD_ABI PYBIND11_BUILD_TYPE "__"
+#define PYBIND11_MODULE_LOCAL_ID                                                                  \
+    "__pybind11_module_local_v" PYBIND11_TOSTRING(PYBIND11_INTERNALS_VERSION)                     \
+        PYBIND11_INTERNALS_KIND PYBIND11_COMPILER_TYPE PYBIND11_STDLIB PYBIND11_BUILD_ABI         \
+            PYBIND11_BUILD_TYPE "__"
 
 /// Each module locally stores a pointer to the `internals` data. The data
 /// itself is shared among modules with the same `PYBIND11_INTERNALS_ID`.
@@ -301,7 +310,7 @@ bool handle_nested_exception(const T &exc, const std::exception_ptr &p) {
 template <class T,
           enable_if_t<!std::is_same<std::nested_exception, remove_cvref_t<T>>::value, int> = 0>
 bool handle_nested_exception(const T &exc, const std::exception_ptr &p) {
-    if (auto *nep = dynamic_cast<const std::nested_exception *>(std::addressof(exc))) {
+    if (const auto *nep = dynamic_cast<const std::nested_exception *>(std::addressof(exc))) {
         return handle_nested_exception(*nep, p);
     }
     return false;
@@ -338,7 +347,7 @@ inline void translate_exception(std::exception_ptr p) {
         return;
     } catch (const builtin_exception &e) {
         // Could not use template since it's an abstract class.
-        if (auto *nep = dynamic_cast<const std::nested_exception *>(std::addressof(e))) {
+        if (const auto *nep = dynamic_cast<const std::nested_exception *>(std::addressof(e))) {
             handle_nested_exception(*nep, p);
         }
         e.set_error();
@@ -388,9 +397,14 @@ inline void translate_exception(std::exception_ptr p) {
 #if !defined(__GLIBCXX__)
 inline void translate_local_exception(std::exception_ptr p) {
     try {
-        if (p) std::rethrow_exception(p);
-    } catch (error_already_set &e)       { e.restore();   return;
-    } catch (const builtin_exception &e) { e.set_error(); return;
+        if (p)
+            std::rethrow_exception(p);
+    } catch (error_already_set &e) {
+        e.restore();
+        return;
+    } catch (const builtin_exception &e) {
+        e.set_error();
+        return;
     }
 }
 #endif
@@ -404,7 +418,7 @@ PYBIND11_NOINLINE internals &get_internals() {
     // Ensure that the GIL is held since we will need to make Python calls.
     // Cannot use py::gil_scoped_acquire here since that constructor calls get_internals.
     struct gil_scoped_acquire_local {
-        gil_scoped_acquire_local() : state (PyGILState_Ensure()) {}
+        gil_scoped_acquire_local() : state(PyGILState_Ensure()) {}
         ~gil_scoped_acquire_local() { PyGILState_Release(state); }
         const PyGILState_STATE state;
     } gil;
@@ -425,7 +439,8 @@ PYBIND11_NOINLINE internals &get_internals() {
         (*internals_pp)->registered_exception_translators.push_front(&translate_local_exception);
 #endif
     } else {
-        if (!internals_pp) internals_pp = new internals*();
+        if (!internals_pp)
+            internals_pp = new internals *();
         auto *&internals_ptr = *internals_pp;
         internals_ptr = new internals();
 #if defined(WITH_THREAD)
@@ -502,11 +517,10 @@ struct local_internals {
 
 /// Works like `get_internals`, but for things which are locally registered.
 inline local_internals &get_local_internals() {
-  static local_internals locals;
-  return locals;
+    static local_internals locals;
+    return locals;
 }
 
-
 /// Constructs a std::string with the given arguments, stores it in `internals`, and returns its
 /// `c_str()`.  Such strings objects have a long storage duration -- the internal strings are only
 /// cleared when the program exits or after interpreter shutdown (when embedding), and so are
@@ -538,7 +552,7 @@ PYBIND11_NOINLINE void *set_shared_data(const std::string &name, void *data) {
 /// Returns a typed reference to a shared data entry (by using `get_shared_data()`) if
 /// such entry exists. Otherwise, a new object of default-constructible type `T` is
 /// added to the shared data under the given name and a reference to it is returned.
-template<typename T>
+template <typename T>
 T &get_or_create_shared_data(const std::string &name) {
     auto &internals = detail::get_internals();
     auto it = internals.shared_data.find(name);
diff --git a/include/pybind11/detail/type_caster_base.h b/include/pybind11/detail/type_caster_base.h
index 48e218b2f3..da62951c8f 100644
--- a/include/pybind11/detail/type_caster_base.h
+++ b/include/pybind11/detail/type_caster_base.h
@@ -14,6 +14,7 @@
 #include "descr.h"
 #include "internals.h"
 #include "typeid.h"
+
 #include <cstdint>
 #include <iterator>
 #include <new>
@@ -32,7 +33,7 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 /// Adding a patient will keep it alive up until the enclosing function returns.
 class loader_life_support {
 private:
-    loader_life_support* parent = nullptr;
+    loader_life_support *parent = nullptr;
     std::unordered_set<PyObject *> keep_alive;
 
 #if defined(WITH_THREAD)
@@ -62,17 +63,14 @@ class loader_life_support {
 
 public:
     /// A new patient frame is created when a function is entered
-    loader_life_support() {
-        parent = get_stack_top();
-        set_stack_top(this);
-    }
+    loader_life_support() : parent{get_stack_top()} { set_stack_top(this); }
 
     /// ... and destroyed after it returns
     ~loader_life_support() {
         if (get_stack_top() != this)
             pybind11_fail("loader_life_support: internal error");
         set_stack_top(parent);
-        for (auto* item : keep_alive)
+        for (auto *item : keep_alive)
             Py_DECREF(item);
     }
 
@@ -98,7 +96,8 @@ class loader_life_support {
 // Gets the cache entry for the given type, creating it if necessary.  The return value is the pair
 // returned by emplace, i.e. an iterator for the entry and a bool set to `true` if the entry was
 // just created.
-inline std::pair<decltype(internals::registered_types_py)::iterator, bool> all_type_info_get_cache(PyTypeObject *type);
+inline std::pair<decltype(internals::registered_types_py)::iterator, bool>
+all_type_info_get_cache(PyTypeObject *type);
 
 // Populates a just-created cache entry.
 PYBIND11_NOINLINE void all_type_info_populate(PyTypeObject *t, std::vector<type_info *> &bases) {
@@ -108,29 +107,33 @@ PYBIND11_NOINLINE void all_type_info_populate(PyTypeObject *t, std::vector<type_
 
     auto const &type_dict = get_internals().registered_types_py;
     for (size_t i = 0; i < check.size(); i++) {
-        auto type = check[i];
+        auto *type = check[i];
         // Ignore Python2 old-style class super type:
-        if (!PyType_Check((PyObject *) type)) continue;
+        if (!PyType_Check((PyObject *) type))
+            continue;
 
         // Check `type` in the current set of registered python types:
         auto it = type_dict.find(type);
         if (it != type_dict.end()) {
             // We found a cache entry for it, so it's either pybind-registered or has pre-computed
-            // pybind bases, but we have to make sure we haven't already seen the type(s) before: we
-            // want to follow Python/virtual C++ rules that there should only be one instance of a
-            // common base.
+            // pybind bases, but we have to make sure we haven't already seen the type(s) before:
+            // we want to follow Python/virtual C++ rules that there should only be one instance of
+            // a common base.
             for (auto *tinfo : it->second) {
                 // NB: Could use a second set here, rather than doing a linear search, but since
                 // having a large number of immediate pybind11-registered types seems fairly
                 // unlikely, that probably isn't worthwhile.
                 bool found = false;
                 for (auto *known : bases) {
-                    if (known == tinfo) { found = true; break; }
+                    if (known == tinfo) {
+                        found = true;
+                        break;
+                    }
                 }
-                if (!found) bases.push_back(tinfo);
+                if (!found)
+                    bases.push_back(tinfo);
             }
-        }
-        else if (type->tp_bases) {
+        } else if (type->tp_bases) {
             // It's some python type, so keep follow its bases classes to look for one or more
             // registered types
             if (i + 1 == check.size()) {
@@ -170,12 +173,13 @@ inline const std::vector<detail::type_info *> &all_type_info(PyTypeObject *type)
  * ancestors are pybind11-registered.  Throws an exception if there are multiple bases--use
  * `all_type_info` instead if you want to support multiple bases.
  */
-PYBIND11_NOINLINE detail::type_info* get_type_info(PyTypeObject *type) {
-    auto &bases = all_type_info(type);
+PYBIND11_NOINLINE detail::type_info *get_type_info(PyTypeObject *type) {
+    const auto &bases = all_type_info(type);
     if (bases.empty())
         return nullptr;
     if (bases.size() > 1)
-        pybind11_fail("pybind11::detail::get_type_info: type has multiple pybind11-registered bases");
+        pybind11_fail(
+            "pybind11::detail::get_type_info: type has multiple pybind11-registered bases");
     return bases.front();
 }
 
@@ -195,18 +199,20 @@ inline detail::type_info *get_global_type_info(const std::type_index &tp) {
     return nullptr;
 }
 
-/// Return the type info for a given C++ type; on lookup failure can either throw or return nullptr.
+/// Return the type info for a given C++ type; on lookup failure can either throw or return
+/// nullptr.
 PYBIND11_NOINLINE detail::type_info *get_type_info(const std::type_index &tp,
-                                                          bool throw_if_missing = false) {
-    if (auto ltype = get_local_type_info(tp))
+                                                   bool throw_if_missing = false) {
+    if (auto *ltype = get_local_type_info(tp))
         return ltype;
-    if (auto gtype = get_global_type_info(tp))
+    if (auto *gtype = get_global_type_info(tp))
         return gtype;
 
     if (throw_if_missing) {
         std::string tname = tp.name();
         detail::clean_type_id(tname);
-        pybind11_fail("pybind11::detail::get_type_info: unable to find type info for \"" + tname + "\"");
+        pybind11_fail("pybind11::detail::get_type_info: unable to find type info for \"" + tname
+                      + "\"");
     }
     return nullptr;
 }
@@ -218,10 +224,10 @@ PYBIND11_NOINLINE handle get_type_handle(const std::type_info &tp, bool throw_if
 
 // Searches the inheritance graph for a registered Python instance, using all_type_info().
 PYBIND11_NOINLINE handle find_registered_python_instance(void *src,
-                                                                const detail::type_info *tinfo) {
+                                                         const detail::type_info *tinfo) {
     auto it_instances = get_internals().registered_instances.equal_range(src);
     for (auto it_i = it_instances.first; it_i != it_instances.second; ++it_i) {
-        for (auto instance_type : detail::all_type_info(Py_TYPE(it_i->second))) {
+        for (auto *instance_type : detail::all_type_info(Py_TYPE(it_i->second))) {
             if (instance_type && same_type(*instance_type->cpptype, *tinfo->cpptype))
                 return handle((PyObject *) it_i->second).inc_ref();
         }
@@ -236,10 +242,10 @@ struct value_and_holder {
     void **vh = nullptr;
 
     // Main constructor for a found value/holder:
-    value_and_holder(instance *i, const detail::type_info *type, size_t vpos, size_t index) :
-        inst{i}, index{index}, type{type},
-        vh{inst->simple_layout ? inst->simple_value_holder : &inst->nonsimple.values_and_holders[vpos]}
-    {}
+    value_and_holder(instance *i, const detail::type_info *type, size_t vpos, size_t index)
+        : inst{i}, index{index}, type{type}, vh{inst->simple_layout
+                                                    ? inst->simple_value_holder
+                                                    : &inst->nonsimple.values_and_holders[vpos]} {}
 
     // Default constructor (used to signal a value-and-holder not found by get_value_and_holder())
     value_and_holder() = default;
@@ -247,13 +253,15 @@ struct value_and_holder {
     // Used for past-the-end iterator
     explicit value_and_holder(size_t index) : index{index} {}
 
-    template <typename V = void> V *&value_ptr() const {
+    template <typename V = void>
+    V *&value_ptr() const {
         return reinterpret_cast<V *&>(vh[0]);
     }
     // True if this `value_and_holder` has a non-null value pointer
     explicit operator bool() const { return value_ptr() != nullptr; }
 
-    template <typename H> H &holder() const {
+    template <typename H>
+    H &holder() const {
         return reinterpret_cast<H &>(vh[1]);
     }
     bool holder_constructed() const {
@@ -272,8 +280,8 @@ struct value_and_holder {
     }
     bool instance_registered() const {
         return inst->simple_layout
-            ? inst->simple_instance_registered
-            : ((inst->nonsimple.status[index] & instance::status_instance_registered) != 0);
+                   ? inst->simple_instance_registered
+                   : ((inst->nonsimple.status[index] & instance::status_instance_registered) != 0);
     }
     // NOLINTNEXTLINE(readability-make-member-function-const)
     void set_instance_registered(bool v = true) {
@@ -305,11 +313,10 @@ struct values_and_holders {
         friend struct values_and_holders;
         iterator(instance *inst, const type_vec *tinfo)
             : inst{inst}, types{tinfo},
-            curr(inst /* instance */,
-                 types->empty() ? nullptr : (*types)[0] /* type info */,
-                 0, /* vpos: (non-simple types only): the first vptr comes first */
-                 0 /* index */)
-        {}
+              curr(inst /* instance */,
+                   types->empty() ? nullptr : (*types)[0] /* type info */,
+                   0, /* vpos: (non-simple types only): the first vptr comes first */
+                   0 /* index */) {}
         // Past-the-end iterator:
         explicit iterator(size_t end) : curr(end) {}
 
@@ -332,7 +339,8 @@ struct values_and_holders {
 
     iterator find(const type_info *find_type) {
         auto it = begin(), endit = end();
-        while (it != endit && it->type != find_type) ++it;
+        while (it != endit && it->type != find_type)
+            ++it;
         return it;
     }
 
@@ -349,7 +357,9 @@ struct values_and_holders {
  * The returned object should be short-lived: in particular, it must not outlive the called-upon
  * instance.
  */
-PYBIND11_NOINLINE value_and_holder instance::get_value_and_holder(const type_info *find_type /*= nullptr default in common.h*/, bool throw_if_missing /*= true in common.h*/) {
+PYBIND11_NOINLINE value_and_holder
+instance::get_value_and_holder(const type_info *find_type /*= nullptr default in common.h*/,
+                               bool throw_if_missing /*= true in common.h*/) {
     // Optimize common case:
     if (!find_type || Py_TYPE(this) == find_type->type)
         return value_and_holder(this, find_type, 0, 0);
@@ -364,44 +374,46 @@ PYBIND11_NOINLINE value_and_holder instance::get_value_and_holder(const type_inf
 
 #if defined(NDEBUG)
     pybind11_fail("pybind11::detail::instance::get_value_and_holder: "
-            "type is not a pybind11 base of the given instance "
-            "(compile in debug mode for type details)");
+                  "type is not a pybind11 base of the given instance "
+                  "(compile in debug mode for type details)");
 #else
-    pybind11_fail("pybind11::detail::instance::get_value_and_holder: `" +
-            get_fully_qualified_tp_name(find_type->type) + "' is not a pybind11 base of the given `" +
-            get_fully_qualified_tp_name(Py_TYPE(this)) + "' instance");
+    pybind11_fail("pybind11::detail::instance::get_value_and_holder: `"
+                  + get_fully_qualified_tp_name(find_type->type)
+                  + "' is not a pybind11 base of the given `"
+                  + get_fully_qualified_tp_name(Py_TYPE(this)) + "' instance");
 #endif
 }
 
 PYBIND11_NOINLINE void instance::allocate_layout() {
-    auto &tinfo = all_type_info(Py_TYPE(this));
+    const auto &tinfo = all_type_info(Py_TYPE(this));
 
     const size_t n_types = tinfo.size();
 
     if (n_types == 0)
-        pybind11_fail("instance allocation failed: new instance has no pybind11-registered base types");
+        pybind11_fail(
+            "instance allocation failed: new instance has no pybind11-registered base types");
 
-    simple_layout =
-        n_types == 1 && tinfo.front()->holder_size_in_ptrs <= instance_simple_holder_in_ptrs();
+    simple_layout
+        = n_types == 1 && tinfo.front()->holder_size_in_ptrs <= instance_simple_holder_in_ptrs();
 
     // Simple path: no python-side multiple inheritance, and a small-enough holder
     if (simple_layout) {
         simple_value_holder[0] = nullptr;
         simple_holder_constructed = false;
         simple_instance_registered = false;
-    }
-    else { // multiple base types or a too-large holder
+    } else { // multiple base types or a too-large holder
         // Allocate space to hold: [v1*][h1][v2*][h2]...[bb...] where [vN*] is a value pointer,
         // [hN] is the (uninitialized) holder instance for value N, and [bb...] is a set of bool
         // values that tracks whether each associated holder has been initialized.  Each [block] is
         // padded, if necessary, to an integer multiple of sizeof(void *).
         size_t space = 0;
-        for (auto t : tinfo) {
-            space += 1; // value pointer
+        for (auto *t : tinfo) {
+            space += 1;                      // value pointer
             space += t->holder_size_in_ptrs; // holder instance
         }
         size_t flags_at = space;
-        space += size_in_ptrs(n_types); // status bytes (holder_constructed and instance_registered)
+        space
+            += size_in_ptrs(n_types); // status bytes (holder_constructed and instance_registered)
 
         // Allocate space for flags, values, and holders, and initialize it to 0 (flags and values,
         // in particular, need to be 0).  Use Python's memory allocation functions: in Python 3.6
@@ -410,13 +422,16 @@ PYBIND11_NOINLINE void instance::allocate_layout() {
         // just wrappers around malloc.
 #if PY_VERSION_HEX >= 0x03050000
         nonsimple.values_and_holders = (void **) PyMem_Calloc(space, sizeof(void *));
-        if (!nonsimple.values_and_holders) throw std::bad_alloc();
+        if (!nonsimple.values_and_holders)
+            throw std::bad_alloc();
 #else
         nonsimple.values_and_holders = (void **) PyMem_New(void *, space);
-        if (!nonsimple.values_and_holders) throw std::bad_alloc();
+        if (!nonsimple.values_and_holders)
+            throw std::bad_alloc();
         std::memset(nonsimple.values_and_holders, 0, space * sizeof(void *));
 #endif
-        nonsimple.status = reinterpret_cast<std::uint8_t *>(&nonsimple.values_and_holders[flags_at]);
+        nonsimple.status
+            = reinterpret_cast<std::uint8_t *>(&nonsimple.values_and_holders[flags_at]);
     }
     owned = true;
 }
@@ -468,17 +483,16 @@ PYBIND11_NOINLINE std::string error_string() {
         PyFrameObject *frame = trace->tb_frame;
         errorString += "\n\nAt:\n";
         while (frame) {
-#if PY_VERSION_HEX >= 0x03090000
+#    if PY_VERSION_HEX >= 0x03090000
             PyCodeObject *f_code = PyFrame_GetCode(frame);
-#else
+#    else
             PyCodeObject *f_code = frame->f_code;
             Py_INCREF(f_code);
-#endif
+#    endif
             int lineno = PyFrame_GetLineNumber(frame);
-            errorString +=
-                "  " + handle(f_code->co_filename).cast<std::string>() +
-                "(" + std::to_string(lineno) + "): " +
-                handle(f_code->co_name).cast<std::string>() + "\n";
+            errorString += "  " + handle(f_code->co_filename).cast<std::string>() + "("
+                           + std::to_string(lineno)
+                           + "): " + handle(f_code->co_name).cast<std::string>() + "\n";
             frame = frame->f_back;
             Py_DECREF(f_code);
         }
@@ -488,7 +502,7 @@ PYBIND11_NOINLINE std::string error_string() {
     return errorString;
 }
 
-PYBIND11_NOINLINE handle get_object_handle(const void *ptr, const detail::type_info *type ) {
+PYBIND11_NOINLINE handle get_object_handle(const void *ptr, const detail::type_info *type) {
     auto &instances = get_internals().registered_instances;
     auto range = instances.equal_range(ptr);
     for (auto it = range.first; it != range.second; ++it) {
@@ -506,9 +520,9 @@ inline PyThreadState *get_thread_state_unchecked() {
 #elif PY_VERSION_HEX < 0x03000000
     return _PyThreadState_Current;
 #elif PY_VERSION_HEX < 0x03050000
-    return (PyThreadState*) _Py_atomic_load_relaxed(&_PyThreadState_Current);
+    return (PyThreadState *) _Py_atomic_load_relaxed(&_PyThreadState_Current);
 #elif PY_VERSION_HEX < 0x03050200
-    return (PyThreadState*) _PyThreadState_Current.value;
+    return (PyThreadState *) _PyThreadState_Current.value;
 #else
     return _PyThreadState_UncheckedGet();
 #endif
@@ -526,11 +540,11 @@ class type_caster_generic {
     explicit type_caster_generic(const type_info *typeinfo)
         : typeinfo(typeinfo), cpptype(typeinfo ? typeinfo->cpptype : nullptr) {}
 
-    bool load(handle src, bool convert) {
-        return load_impl<type_caster_generic>(src, convert);
-    }
+    bool load(handle src, bool convert) { return load_impl<type_caster_generic>(src, convert); }
 
-    PYBIND11_NOINLINE static handle cast(const void *_src, return_value_policy policy, handle parent,
+    PYBIND11_NOINLINE static handle cast(const void *_src,
+                                         return_value_policy policy,
+                                         handle parent,
                                          const detail::type_info *tinfo,
                                          void *(*copy_constructor)(const void *),
                                          void *(*move_constructor)(const void *),
@@ -546,7 +560,7 @@ class type_caster_generic {
             return registered_inst;
 
         auto inst = reinterpret_steal<object>(make_new_instance(tinfo->type));
-        auto wrapper = reinterpret_cast<instance *>(inst.ptr());
+        auto *wrapper = reinterpret_cast<instance *>(inst.ptr());
         wrapper->owned = false;
         void *&valueptr = values_and_holders(wrapper).begin()->value_ptr();
 
@@ -573,8 +587,8 @@ class type_caster_generic {
 #else
                     std::string type_name(tinfo->cpptype->name());
                     detail::clean_type_id(type_name);
-                    throw cast_error("return_value_policy = copy, but type " +
-                                     type_name + " is non-copyable!");
+                    throw cast_error("return_value_policy = copy, but type " + type_name
+                                     + " is non-copyable!");
 #endif
                 }
                 wrapper->owned = true;
@@ -593,8 +607,8 @@ class type_caster_generic {
 #else
                     std::string type_name(tinfo->cpptype->name());
                     detail::clean_type_id(type_name);
-                    throw cast_error("return_value_policy = move, but type " +
-                                     type_name + " is neither movable nor copyable!");
+                    throw cast_error("return_value_policy = move, but type " + type_name
+                                     + " is neither movable nor copyable!");
 #endif
                 }
                 wrapper->owned = true;
@@ -620,23 +634,22 @@ class type_caster_generic {
         auto *&vptr = v_h.value_ptr();
         // Lazy allocation for unallocated values:
         if (vptr == nullptr) {
-            auto *type = v_h.type ? v_h.type : typeinfo;
+            const auto *type = v_h.type ? v_h.type : typeinfo;
             if (type->operator_new) {
                 vptr = type->operator_new(type->type_size);
             } else {
-                #if defined(__cpp_aligned_new) && (!defined(_MSC_VER) || _MSC_VER >= 1912)
-                    if (type->type_align > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
-                        vptr = ::operator new(type->type_size,
-                                              std::align_val_t(type->type_align));
-                    else
-                #endif
-                vptr = ::operator new(type->type_size);
+#if defined(__cpp_aligned_new) && (!defined(_MSC_VER) || _MSC_VER >= 1912)
+                if (type->type_align > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
+                    vptr = ::operator new(type->type_size, std::align_val_t(type->type_align));
+                else
+#endif
+                    vptr = ::operator new(type->type_size);
             }
         }
         value = vptr;
     }
     bool try_implicit_casts(handle src, bool convert) {
-        for (auto &cast : typeinfo->implicit_casts) {
+        for (const auto &cast : typeinfo->implicit_casts) {
             type_caster_generic sub_caster(*cast.first);
             if (sub_caster.load(src, convert)) {
                 value = cast.second(sub_caster.value);
@@ -670,12 +683,13 @@ class type_caster_generic {
             return false;
 
         type_info *foreign_typeinfo = reinterpret_borrow<capsule>(getattr(pytype, local_key));
-        // Only consider this foreign loader if actually foreign and is a loader of the correct cpp type
+        // Only consider this foreign loader if actually foreign and is a loader of the correct cpp
+        // type
         if (foreign_typeinfo->module_local_load == &local_load
             || (cpptype && !same_type(*cpptype, *foreign_typeinfo->cpptype)))
             return false;
 
-        if (auto result = foreign_typeinfo->module_local_load(src.ptr(), foreign_typeinfo)) {
+        if (auto *result = foreign_typeinfo->module_local_load(src.ptr(), foreign_typeinfo)) {
             value = result;
             return true;
         }
@@ -687,8 +701,10 @@ class type_caster_generic {
     // logic (without having to resort to virtual inheritance).
     template <typename ThisT>
     PYBIND11_NOINLINE bool load_impl(handle src, bool convert) {
-        if (!src) return false;
-        if (!typeinfo) return try_load_foreign_module_local(src);
+        if (!src)
+            return false;
+        if (!typeinfo)
+            return try_load_foreign_module_local(src);
 
         auto &this_ = static_cast<ThisT &>(*this);
         this_.check_holder_compat();
@@ -703,7 +719,7 @@ class type_caster_generic {
         }
         // Case 2: We have a derived class
         if (PyType_IsSubtype(srctype, typeinfo->type)) {
-            auto &bases = all_type_info(srctype);
+            const auto &bases = all_type_info(srctype);
             bool no_cpp_mi = typeinfo->simple_type;
 
             // Case 2a: the python type is a Python-inherited derived class that inherits from just
@@ -716,28 +732,30 @@ class type_caster_generic {
                 this_.load_value(reinterpret_cast<instance *>(src.ptr())->get_value_and_holder());
                 return true;
             }
-            // Case 2b: the python type inherits from multiple C++ bases.  Check the bases to see if
-            // we can find an exact match (or, for a simple C++ type, an inherited match); if so, we
-            // can safely reinterpret_cast to the relevant pointer.
+            // Case 2b: the python type inherits from multiple C++ bases.  Check the bases to see
+            // if we can find an exact match (or, for a simple C++ type, an inherited match); if
+            // so, we can safely reinterpret_cast to the relevant pointer.
             if (bases.size() > 1) {
-                for (auto base : bases) {
-                    if (no_cpp_mi ? PyType_IsSubtype(base->type, typeinfo->type) : base->type == typeinfo->type) {
-                        this_.load_value(reinterpret_cast<instance *>(src.ptr())->get_value_and_holder(base));
+                for (auto *base : bases) {
+                    if (no_cpp_mi ? PyType_IsSubtype(base->type, typeinfo->type)
+                                  : base->type == typeinfo->type) {
+                        this_.load_value(
+                            reinterpret_cast<instance *>(src.ptr())->get_value_and_holder(base));
                         return true;
                     }
                 }
             }
 
-            // Case 2c: C++ multiple inheritance is involved and we couldn't find an exact type match
-            // in the registered bases, above, so try implicit casting (needed for proper C++ casting
-            // when MI is involved).
+            // Case 2c: C++ multiple inheritance is involved and we couldn't find an exact type
+            // match in the registered bases, above, so try implicit casting (needed for proper C++
+            // casting when MI is involved).
             if (this_.try_implicit_casts(src, convert))
                 return true;
         }
 
         // Perform an implicit conversion
         if (convert) {
-            for (auto &converter : typeinfo->implicit_conversions) {
+            for (const auto &converter : typeinfo->implicit_conversions) {
                 auto temp = reinterpret_steal<object>(converter(src.ptr(), typeinfo->type));
                 if (load_impl<ThisT>(temp, false)) {
                     loader_life_support::add_patient(temp);
@@ -750,7 +768,7 @@ class type_caster_generic {
 
         // Failed to match local typeinfo. Try again with global.
         if (typeinfo->module_local) {
-            if (auto gtype = get_global_type_info(*typeinfo->cpptype)) {
+            if (auto *gtype = get_global_type_info(*typeinfo->cpptype)) {
                 typeinfo = gtype;
                 return load(src, false);
             }
@@ -758,26 +776,28 @@ class type_caster_generic {
 
         // Global typeinfo has precedence over foreign module_local
         if (try_load_foreign_module_local(src)) {
-           return true;
+            return true;
         }
 
         // Custom converters didn't take None, now we convert None to nullptr.
         if (src.is_none()) {
-           // Defer accepting None to other overloads (if we aren't in convert mode):
-           if (!convert) return false;
-           value = nullptr;
-           return true;
+            // Defer accepting None to other overloads (if we aren't in convert mode):
+            if (!convert)
+                return false;
+            value = nullptr;
+            return true;
         }
 
         return false;
     }
 
-
     // Called to do type lookup and wrap the pointer and type in a pair when a dynamic_cast
     // isn't needed or can't be used.  If the type is unknown, sets the error and returns a pair
     // with .second = nullptr.  (p.first = nullptr is not an error: it becomes None).
-    PYBIND11_NOINLINE static std::pair<const void *, const type_info *> src_and_type(
-            const void *src, const std::type_info &cast_type, const std::type_info *rtti_type = nullptr) {
+    PYBIND11_NOINLINE static std::pair<const void *, const type_info *>
+    src_and_type(const void *src,
+                 const std::type_info &cast_type,
+                 const std::type_info *rtti_type = nullptr) {
         if (auto *tpi = get_type_info(cast_type))
             return {src, const_cast<const type_info *>(tpi)};
 
@@ -802,10 +822,9 @@ class type_caster_generic {
  * `movable_cast_op_type` instead.
  */
 template <typename T>
-using cast_op_type =
-    conditional_t<std::is_pointer<remove_reference_t<T>>::value,
-        typename std::add_pointer<intrinsic_t<T>>::type,
-        typename std::add_lvalue_reference<intrinsic_t<T>>::type>;
+using cast_op_type = conditional_t<std::is_pointer<remove_reference_t<T>>::value,
+                                   typename std::add_pointer<intrinsic_t<T>>::type,
+                                   typename std::add_lvalue_reference<intrinsic_t<T>>::type>;
 
 /**
  * Determine suitable casting operator for a type caster with a movable value.  Such a type caster
@@ -815,40 +834,50 @@ using cast_op_type =
  * These operator are automatically provided when using the PYBIND11_TYPE_CASTER macro.
  */
 template <typename T>
-using movable_cast_op_type =
-    conditional_t<std::is_pointer<typename std::remove_reference<T>::type>::value,
-        typename std::add_pointer<intrinsic_t<T>>::type,
-    conditional_t<std::is_rvalue_reference<T>::value,
-        typename std::add_rvalue_reference<intrinsic_t<T>>::type,
-        typename std::add_lvalue_reference<intrinsic_t<T>>::type>>;
+using movable_cast_op_type
+    = conditional_t<std::is_pointer<typename std::remove_reference<T>::type>::value,
+                    typename std::add_pointer<intrinsic_t<T>>::type,
+                    conditional_t<std::is_rvalue_reference<T>::value,
+                                  typename std::add_rvalue_reference<intrinsic_t<T>>::type,
+                                  typename std::add_lvalue_reference<intrinsic_t<T>>::type>>;
 
 // std::is_copy_constructible isn't quite enough: it lets std::vector<T> (and similar) through when
 // T is non-copyable, but code containing such a copy constructor fails to actually compile.
-template <typename T, typename SFINAE = void> struct is_copy_constructible : std::is_copy_constructible<T> {};
+template <typename T, typename SFINAE = void>
+struct is_copy_constructible : std::is_copy_constructible<T> {};
 
 // Specialization for types that appear to be copy constructible but also look like stl containers
 // (we specifically check for: has `value_type` and `reference` with `reference = value_type&`): if
 // so, copy constructability depends on whether the value_type is copy constructible.
-template <typename Container> struct is_copy_constructible<Container, enable_if_t<all_of<
-        std::is_copy_constructible<Container>,
-        std::is_same<typename Container::value_type &, typename Container::reference>,
-        // Avoid infinite recursion
-        negation<std::is_same<Container, typename Container::value_type>>
-    >::value>> : is_copy_constructible<typename Container::value_type> {};
+template <typename Container>
+struct is_copy_constructible<
+    Container,
+    enable_if_t<
+        all_of<std::is_copy_constructible<Container>,
+               std::is_same<typename Container::value_type &, typename Container::reference>,
+               // Avoid infinite recursion
+               negation<std::is_same<Container, typename Container::value_type>>>::value>>
+    : is_copy_constructible<typename Container::value_type> {};
 
 // Likewise for std::pair
-// (after C++17 it is mandatory that the copy constructor not exist when the two types aren't themselves
-// copy constructible, but this can not be relied upon when T1 or T2 are themselves containers).
-template <typename T1, typename T2> struct is_copy_constructible<std::pair<T1, T2>>
+// (after C++17 it is mandatory that the copy constructor not exist when the two types aren't
+// themselves copy constructible, but this can not be relied upon when T1 or T2 are themselves
+// containers).
+template <typename T1, typename T2>
+struct is_copy_constructible<std::pair<T1, T2>>
     : all_of<is_copy_constructible<T1>, is_copy_constructible<T2>> {};
 
 // The same problems arise with std::is_copy_assignable, so we use the same workaround.
-template <typename T, typename SFINAE = void> struct is_copy_assignable : std::is_copy_assignable<T> {};
-template <typename Container> struct is_copy_assignable<Container, enable_if_t<all_of<
-        std::is_copy_assignable<Container>,
-        std::is_same<typename Container::value_type &, typename Container::reference>
-    >::value>> : is_copy_assignable<typename Container::value_type> {};
-template <typename T1, typename T2> struct is_copy_assignable<std::pair<T1, T2>>
+template <typename T, typename SFINAE = void>
+struct is_copy_assignable : std::is_copy_assignable<T> {};
+template <typename Container>
+struct is_copy_assignable<Container,
+                          enable_if_t<all_of<std::is_copy_assignable<Container>,
+                                             std::is_same<typename Container::value_type &,
+                                                          typename Container::reference>>::value>>
+    : is_copy_assignable<typename Container::value_type> {};
+template <typename T1, typename T2>
+struct is_copy_assignable<std::pair<T1, T2>>
     : all_of<is_copy_assignable<T1>, is_copy_assignable<T2>> {};
 
 PYBIND11_NAMESPACE_END(detail)
@@ -875,16 +904,14 @@ PYBIND11_NAMESPACE_END(detail)
 // std::enable_if. User provided specializations will always have higher priority than
 // the default implementation and specialization provided in polymorphic_type_hook_base.
 template <typename itype, typename SFINAE = void>
-struct polymorphic_type_hook_base
-{
-    static const void *get(const itype *src, const std::type_info*&) { return src; }
+struct polymorphic_type_hook_base {
+    static const void *get(const itype *src, const std::type_info *&) { return src; }
 };
 template <typename itype>
-struct polymorphic_type_hook_base<itype, detail::enable_if_t<std::is_polymorphic<itype>::value>>
-{
-    static const void *get(const itype *src, const std::type_info*& type) {
+struct polymorphic_type_hook_base<itype, detail::enable_if_t<std::is_polymorphic<itype>::value>> {
+    static const void *get(const itype *src, const std::type_info *&type) {
         type = src ? &typeid(*src) : nullptr;
-        return dynamic_cast<const void*>(src);
+        return dynamic_cast<const void *>(src);
     }
 };
 template <typename itype, typename SFINAE = void>
@@ -893,17 +920,19 @@ struct polymorphic_type_hook : public polymorphic_type_hook_base<itype> {};
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 /// Generic type caster for objects stored on the heap
-template <typename type> class type_caster_base : public type_caster_generic {
+template <typename type>
+class type_caster_base : public type_caster_generic {
     using itype = intrinsic_t<type>;
 
 public:
     static constexpr auto name = const_name<type>();
 
-    type_caster_base() : type_caster_base(typeid(type)) { }
-    explicit type_caster_base(const std::type_info &info) : type_caster_generic(info) { }
+    type_caster_base() : type_caster_base(typeid(type)) {}
+    explicit type_caster_base(const std::type_info &info) : type_caster_generic(info) {}
 
     static handle cast(const itype &src, return_value_policy policy, handle parent) {
-        if (policy == return_value_policy::automatic || policy == return_value_policy::automatic_reference)
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference)
             policy = return_value_policy::copy;
         return cast(&src, policy, parent);
     }
@@ -916,7 +945,7 @@ template <typename type> class type_caster_base : public type_caster_generic {
     // polymorphic type (using RTTI by default, but can be overridden by specializing
     // polymorphic_type_hook). If the instance isn't derived, returns the base version.
     static std::pair<const void *, const type_info *> src_and_type(const itype *src) {
-        auto &cast_type = typeid(itype);
+        const auto &cast_type = typeid(itype);
         const std::type_info *instance_type = nullptr;
         const void *vsrc = polymorphic_type_hook<itype>::get(src, instance_type);
         if (instance_type && !same_type(cast_type, *instance_type)) {
@@ -931,47 +960,59 @@ template <typename type> class type_caster_base : public type_caster_generic {
             if (const auto *tpi = get_type_info(*instance_type))
                 return {vsrc, tpi};
         }
-        // Otherwise we have either a nullptr, an `itype` pointer, or an unknown derived pointer, so
-        // don't do a cast
+        // Otherwise we have either a nullptr, an `itype` pointer, or an unknown derived pointer,
+        // so don't do a cast
         return type_caster_generic::src_and_type(src, cast_type, instance_type);
     }
 
     static handle cast(const itype *src, return_value_policy policy, handle parent) {
         auto st = src_and_type(src);
-        return type_caster_generic::cast(
-            st.first, policy, parent, st.second,
-            make_copy_constructor(src), make_move_constructor(src));
+        return type_caster_generic::cast(st.first,
+                                         policy,
+                                         parent,
+                                         st.second,
+                                         make_copy_constructor(src),
+                                         make_move_constructor(src));
     }
 
     static handle cast_holder(const itype *src, const void *holder) {
         auto st = src_and_type(src);
-        return type_caster_generic::cast(
-            st.first, return_value_policy::take_ownership, {}, st.second,
-            nullptr, nullptr, holder);
+        return type_caster_generic::cast(st.first,
+                                         return_value_policy::take_ownership,
+                                         {},
+                                         st.second,
+                                         nullptr,
+                                         nullptr,
+                                         holder);
     }
 
-    template <typename T> using cast_op_type = detail::cast_op_type<T>;
+    template <typename T>
+    using cast_op_type = detail::cast_op_type<T>;
 
     // NOLINTNEXTLINE(google-explicit-constructor)
-    operator itype*() { return (type *) value; }
+    operator itype *() { return (type *) value; }
     // NOLINTNEXTLINE(google-explicit-constructor)
-    operator itype&() { if (!value) throw reference_cast_error(); return *((itype *) value); }
+    operator itype &() {
+        if (!value)
+            throw reference_cast_error();
+        return *((itype *) value);
+    }
 
 protected:
-    using Constructor = void *(*)(const void *);
+    using Constructor = void *(*) (const void *);
 
     /* Only enabled when the types are {copy,move}-constructible *and* when the type
-       does not have a private operator new implementation. A comma operator is used in the decltype
-       argument to apply SFINAE to the public copy/move constructors.*/
+       does not have a private operator new implementation. A comma operator is used in the
+       decltype argument to apply SFINAE to the public copy/move constructors.*/
     template <typename T, typename = enable_if_t<is_copy_constructible<T>::value>>
-    static auto make_copy_constructor(const T *) -> decltype(new T(std::declval<const T>()), Constructor{}) {
-        return [](const void *arg) -> void * {
-            return new T(*reinterpret_cast<const T *>(arg));
-        };
+    static auto make_copy_constructor(const T *)
+        -> decltype(new T(std::declval<const T>()), Constructor{}) {
+        return [](const void *arg) -> void * { return new T(*reinterpret_cast<const T *>(arg)); };
     }
 
     template <typename T, typename = enable_if_t<std::is_move_constructible<T>::value>>
-    static auto make_move_constructor(const T *) -> decltype(new T(std::declval<T&&>()), Constructor{}) {
+    static auto make_move_constructor(const T *)
+        -> decltype(new T(std::declval<T &&>()), Constructor{}) {
         return [](const void *arg) -> void * {
             return new T(std::move(*const_cast<T *>(reinterpret_cast<const T *>(arg))));
         };
diff --git a/include/pybind11/detail/typeid.h b/include/pybind11/detail/typeid.h
index 39ba8ce0f7..43d27bfb92 100644
--- a/include/pybind11/detail/typeid.h
+++ b/include/pybind11/detail/typeid.h
@@ -13,7 +13,7 @@
 #include <cstdlib>
 
 #if defined(__GNUG__)
-#include <cxxabi.h>
+#    include <cxxabi.h>
 #endif
 
 #include "common.h"
@@ -24,7 +24,8 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 inline void erase_all(std::string &string, const std::string &search) {
     for (size_t pos = 0;;) {
         pos = string.find(search, pos);
-        if (pos == std::string::npos) break;
+        if (pos == std::string::npos)
+            break;
         string.erase(pos, search.length());
     }
 }
@@ -32,8 +33,8 @@ inline void erase_all(std::string &string, const std::string &search) {
 PYBIND11_NOINLINE void clean_type_id(std::string &name) {
 #if defined(__GNUG__)
     int status = 0;
-    std::unique_ptr<char, void (*)(void *)> res {
-        abi::__cxa_demangle(name.c_str(), nullptr, nullptr, &status), std::free };
+    std::unique_ptr<char, void (*)(void *)> res{
+        abi::__cxa_demangle(name.c_str(), nullptr, nullptr, &status), std::free};
     if (status == 0)
         name = res.get();
 #else
@@ -46,7 +47,8 @@ PYBIND11_NOINLINE void clean_type_id(std::string &name) {
 PYBIND11_NAMESPACE_END(detail)
 
 /// Return a string representation of a C++ type
-template <typename T> static std::string type_id() {
+template <typename T>
+static std::string type_id() {
     std::string name(typeid(T).name());
     detail::clean_type_id(name);
     return name;
diff --git a/include/pybind11/eigen.h b/include/pybind11/eigen.h
index 696099fa65..2ffbf306ad 100644
--- a/include/pybind11/eigen.h
+++ b/include/pybind11/eigen.h
@@ -23,122 +23,145 @@
 // 2. we definitely want to ignore any MSVC warnings originating from Eigen code,
 // it is probably best to keep this around indefinitely.
 #if defined(_MSC_VER)
-#  pragma warning(push)
-#  pragma warning(disable: 4127) // C4127: conditional expression is constant
+#    pragma warning(push)
+#    pragma warning(disable : 4127) // C4127: conditional expression is constant
 #endif
 
 #include <Eigen/Core>
 #include <Eigen/SparseCore>
 
 #if defined(_MSC_VER)
-#  pragma warning(pop)
+#    pragma warning(pop)
 #endif
 
 // Eigen prior to 3.2.7 doesn't have proper move constructors--but worse, some classes get implicit
 // move constructors that break things.  We could detect this an explicitly copy, but an extra copy
 // of matrices seems highly undesirable.
-static_assert(EIGEN_VERSION_AT_LEAST(3,2,7), "Eigen support in pybind11 requires Eigen >= 3.2.7");
+static_assert(EIGEN_VERSION_AT_LEAST(3, 2, 7),
+              "Eigen support in pybind11 requires Eigen >= 3.2.7");
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 
 // Provide a convenience alias for easier pass-by-ref usage with fully dynamic strides:
 using EigenDStride = Eigen::Stride<Eigen::Dynamic, Eigen::Dynamic>;
-template <typename MatrixType> using EigenDRef = Eigen::Ref<MatrixType, 0, EigenDStride>;
-template <typename MatrixType> using EigenDMap = Eigen::Map<MatrixType, 0, EigenDStride>;
+template <typename MatrixType>
+using EigenDRef = Eigen::Ref<MatrixType, 0, EigenDStride>;
+template <typename MatrixType>
+using EigenDMap = Eigen::Map<MatrixType, 0, EigenDStride>;
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 
-#if EIGEN_VERSION_AT_LEAST(3,3,0)
+#if EIGEN_VERSION_AT_LEAST(3, 3, 0)
 using EigenIndex = Eigen::Index;
-template<typename Scalar, int Flags, typename StorageIndex>
+template <typename Scalar, int Flags, typename StorageIndex>
 using EigenMapSparseMatrix = Eigen::Map<Eigen::SparseMatrix<Scalar, Flags, StorageIndex>>;
 #else
 using EigenIndex = EIGEN_DEFAULT_DENSE_INDEX_TYPE;
-template<typename Scalar, int Flags, typename StorageIndex>
+template <typename Scalar, int Flags, typename StorageIndex>
 using EigenMapSparseMatrix = Eigen::MappedSparseMatrix<Scalar, Flags, StorageIndex>;
 #endif
 
 // Matches Eigen::Map, Eigen::Ref, blocks, etc:
-template <typename T> using is_eigen_dense_map = all_of<is_template_base_of<Eigen::DenseBase, T>, std::is_base_of<Eigen::MapBase<T, Eigen::ReadOnlyAccessors>, T>>;
-template <typename T> using is_eigen_mutable_map = std::is_base_of<Eigen::MapBase<T, Eigen::WriteAccessors>, T>;
-template <typename T> using is_eigen_dense_plain = all_of<negation<is_eigen_dense_map<T>>, is_template_base_of<Eigen::PlainObjectBase, T>>;
-template <typename T> using is_eigen_sparse = is_template_base_of<Eigen::SparseMatrixBase, T>;
+template <typename T>
+using is_eigen_dense_map = all_of<is_template_base_of<Eigen::DenseBase, T>,
+                                  std::is_base_of<Eigen::MapBase<T, Eigen::ReadOnlyAccessors>, T>>;
+template <typename T>
+using is_eigen_mutable_map = std::is_base_of<Eigen::MapBase<T, Eigen::WriteAccessors>, T>;
+template <typename T>
+using is_eigen_dense_plain
+    = all_of<negation<is_eigen_dense_map<T>>, is_template_base_of<Eigen::PlainObjectBase, T>>;
+template <typename T>
+using is_eigen_sparse = is_template_base_of<Eigen::SparseMatrixBase, T>;
 // Test for objects inheriting from EigenBase<Derived> that aren't captured by the above.  This
 // basically covers anything that can be assigned to a dense matrix but that don't have a typical
 // matrix data layout that can be copied from their .data().  For example, DiagonalMatrix and
 // SelfAdjointView fall into this category.
-template <typename T> using is_eigen_other = all_of<
-    is_template_base_of<Eigen::EigenBase, T>,
-    negation<any_of<is_eigen_dense_map<T>, is_eigen_dense_plain<T>, is_eigen_sparse<T>>>
->;
+template <typename T>
+using is_eigen_other
+    = all_of<is_template_base_of<Eigen::EigenBase, T>,
+             negation<any_of<is_eigen_dense_map<T>, is_eigen_dense_plain<T>, is_eigen_sparse<T>>>>;
 
 // Captures numpy/eigen conformability status (returned by EigenProps::conformable()):
-template <bool EigenRowMajor> struct EigenConformable {
+template <bool EigenRowMajor>
+struct EigenConformable {
     bool conformable = false;
     EigenIndex rows = 0, cols = 0;
-    EigenDStride stride{0, 0};      // Only valid if negativestrides is false!
-    bool negativestrides = false;   // If true, do not use stride!
+    EigenDStride stride{0, 0};    // Only valid if negativestrides is false!
+    bool negativestrides = false; // If true, do not use stride!
 
     // NOLINTNEXTLINE(google-explicit-constructor)
     EigenConformable(bool fits = false) : conformable{fits} {}
     // Matrix type:
-    EigenConformable(EigenIndex r, EigenIndex c,
-            EigenIndex rstride, EigenIndex cstride) :
-        conformable{true}, rows{r}, cols{c},
-        //TODO: when Eigen bug #747 is fixed, remove the tests for non-negativity. http://eigen.tuxfamily.org/bz/show_bug.cgi?id=747
-        stride{EigenRowMajor ? (rstride > 0 ? rstride : 0) : (cstride > 0 ? cstride : 0) /* outer stride */,
-               EigenRowMajor ? (cstride > 0 ? cstride : 0) : (rstride > 0 ? rstride : 0) /* inner stride */ },
-        negativestrides{rstride < 0 || cstride < 0} {
-
-    }
+    EigenConformable(EigenIndex r, EigenIndex c, EigenIndex rstride, EigenIndex cstride)
+        : conformable{true}, rows{r}, cols{c},
+          // TODO: when Eigen bug #747 is fixed, remove the tests for non-negativity.
+          // http://eigen.tuxfamily.org/bz/show_bug.cgi?id=747
+          stride{EigenRowMajor ? (rstride > 0 ? rstride : 0)
+                               : (cstride > 0 ? cstride : 0) /* outer stride */,
+                 EigenRowMajor ? (cstride > 0 ? cstride : 0)
+                               : (rstride > 0 ? rstride : 0) /* inner stride */},
+          negativestrides{rstride < 0 || cstride < 0} {}
     // Vector type:
     EigenConformable(EigenIndex r, EigenIndex c, EigenIndex stride)
-        : EigenConformable(r, c, r == 1 ? c*stride : stride, c == 1 ? r : r*stride) {}
+        : EigenConformable(r, c, r == 1 ? c * stride : stride, c == 1 ? r : r * stride) {}
 
-    template <typename props> bool stride_compatible() const {
+    template <typename props>
+    bool stride_compatible() const {
         // To have compatible strides, we need (on both dimensions) one of fully dynamic strides,
-        // matching strides, or a dimension size of 1 (in which case the stride value is irrelevant)
-        return
-            !negativestrides &&
-            (props::inner_stride == Eigen::Dynamic || props::inner_stride == stride.inner() ||
-                (EigenRowMajor ? cols : rows) == 1) &&
-            (props::outer_stride == Eigen::Dynamic || props::outer_stride == stride.outer() ||
-                (EigenRowMajor ? rows : cols) == 1);
+        // matching strides, or a dimension size of 1 (in which case the stride value is
+        // irrelevant)
+        return !negativestrides
+               && (props::inner_stride == Eigen::Dynamic || props::inner_stride == stride.inner()
+                   || (EigenRowMajor ? cols : rows) == 1)
+               && (props::outer_stride == Eigen::Dynamic || props::outer_stride == stride.outer()
+                   || (EigenRowMajor ? rows : cols) == 1);
     }
     // NOLINTNEXTLINE(google-explicit-constructor)
     operator bool() const { return conformable; }
 };
 
-template <typename Type> struct eigen_extract_stride { using type = Type; };
+template <typename Type>
+struct eigen_extract_stride {
+    using type = Type;
+};
 template <typename PlainObjectType, int MapOptions, typename StrideType>
-struct eigen_extract_stride<Eigen::Map<PlainObjectType, MapOptions, StrideType>> { using type = StrideType; };
+struct eigen_extract_stride<Eigen::Map<PlainObjectType, MapOptions, StrideType>> {
+    using type = StrideType;
+};
 template <typename PlainObjectType, int Options, typename StrideType>
-struct eigen_extract_stride<Eigen::Ref<PlainObjectType, Options, StrideType>> { using type = StrideType; };
+struct eigen_extract_stride<Eigen::Ref<PlainObjectType, Options, StrideType>> {
+    using type = StrideType;
+};
 
 // Helper struct for extracting information from an Eigen type
-template <typename Type_> struct EigenProps {
+template <typename Type_>
+struct EigenProps {
     using Type = Type_;
     using Scalar = typename Type::Scalar;
     using StrideType = typename eigen_extract_stride<Type>::type;
-    static constexpr EigenIndex
-        rows = Type::RowsAtCompileTime,
-        cols = Type::ColsAtCompileTime,
-        size = Type::SizeAtCompileTime;
-    static constexpr bool
-        row_major = Type::IsRowMajor,
-        vector = Type::IsVectorAtCompileTime, // At least one dimension has fixed size 1
-        fixed_rows = rows != Eigen::Dynamic,
-        fixed_cols = cols != Eigen::Dynamic,
-        fixed = size != Eigen::Dynamic, // Fully-fixed size
-        dynamic = !fixed_rows && !fixed_cols; // Fully-dynamic size
-
-    template <EigenIndex i, EigenIndex ifzero> using if_zero = std::integral_constant<EigenIndex, i == 0 ? ifzero : i>;
-    static constexpr EigenIndex inner_stride = if_zero<StrideType::InnerStrideAtCompileTime, 1>::value,
-                                outer_stride = if_zero<StrideType::OuterStrideAtCompileTime,
-                                                       vector ? size : row_major ? cols : rows>::value;
-    static constexpr bool dynamic_stride = inner_stride == Eigen::Dynamic && outer_stride == Eigen::Dynamic;
-    static constexpr bool requires_row_major = !dynamic_stride && !vector && (row_major ? inner_stride : outer_stride) == 1;
-    static constexpr bool requires_col_major = !dynamic_stride && !vector && (row_major ? outer_stride : inner_stride) == 1;
+    static constexpr EigenIndex rows = Type::RowsAtCompileTime, cols = Type::ColsAtCompileTime,
+                                size = Type::SizeAtCompileTime;
+    static constexpr bool row_major = Type::IsRowMajor,
+                          vector
+                          = Type::IsVectorAtCompileTime, // At least one dimension has fixed size 1
+        fixed_rows = rows != Eigen::Dynamic, fixed_cols = cols != Eigen::Dynamic,
+                          fixed = size != Eigen::Dynamic, // Fully-fixed size
+        dynamic = !fixed_rows && !fixed_cols;             // Fully-dynamic size
+
+    template <EigenIndex i, EigenIndex ifzero>
+    using if_zero = std::integral_constant<EigenIndex, i == 0 ? ifzero : i>;
+    static constexpr EigenIndex inner_stride
+        = if_zero<StrideType::InnerStrideAtCompileTime, 1>::value,
+        outer_stride = if_zero < StrideType::OuterStrideAtCompileTime,
+        vector      ? size
+        : row_major ? cols
+                    : rows > ::value;
+    static constexpr bool dynamic_stride
+        = inner_stride == Eigen::Dynamic && outer_stride == Eigen::Dynamic;
+    static constexpr bool requires_row_major
+        = !dynamic_stride && !vector && (row_major ? inner_stride : outer_stride) == 1;
+    static constexpr bool requires_col_major
+        = !dynamic_stride && !vector && (row_major ? outer_stride : inner_stride) == 1;
 
     // Takes an input array and determines whether we can make it fit into the Eigen type.  If
     // the array is a vector, we attempt to fit it into either an Eigen 1xN or Nx1 vector
@@ -150,22 +173,20 @@ template <typename Type_> struct EigenProps {
 
         if (dims == 2) { // Matrix type: require exact match (or dynamic)
 
-            EigenIndex
-                np_rows = a.shape(0),
-                np_cols = a.shape(1),
-                np_rstride = a.strides(0) / static_cast<ssize_t>(sizeof(Scalar)),
-                np_cstride = a.strides(1) / static_cast<ssize_t>(sizeof(Scalar));
-            if ((PYBIND11_SILENCE_MSVC_C4127(fixed_rows) && np_rows != rows) ||
-                (PYBIND11_SILENCE_MSVC_C4127(fixed_cols) && np_cols != cols))
+            EigenIndex np_rows = a.shape(0), np_cols = a.shape(1),
+                       np_rstride = a.strides(0) / static_cast<ssize_t>(sizeof(Scalar)),
+                       np_cstride = a.strides(1) / static_cast<ssize_t>(sizeof(Scalar));
+            if ((PYBIND11_SILENCE_MSVC_C4127(fixed_rows) && np_rows != rows)
+                || (PYBIND11_SILENCE_MSVC_C4127(fixed_cols) && np_cols != cols))
                 return false;
 
             return {np_rows, np_cols, np_rstride, np_cstride};
         }
 
-        // Otherwise we're storing an n-vector.  Only one of the strides will be used, but whichever
-        // is used, we want the (single) numpy stride value.
+        // Otherwise we're storing an n-vector.  Only one of the strides will be used, but
+        // whichever is used, we want the (single) numpy stride value.
         const EigenIndex n = a.shape(0),
-              stride = a.strides(0) / static_cast<ssize_t>(sizeof(Scalar));
+                         stride = a.strides(0) / static_cast<ssize_t>(sizeof(Scalar));
 
         if (vector) { // Eigen type is a compile-time vector
             if (PYBIND11_SILENCE_MSVC_C4127(fixed) && size != n)
@@ -179,45 +200,52 @@ template <typename Type_> struct EigenProps {
         if (fixed_cols) {
             // Since this isn't a vector, cols must be != 1.  We allow this only if it exactly
             // equals the number of elements (rows is Dynamic, and so 1 row is allowed).
-            if (cols != n) return false;
+            if (cols != n)
+                return false;
             return {1, n, stride};
         } // Otherwise it's either fully dynamic, or column dynamic; both become a column vector
-            if (PYBIND11_SILENCE_MSVC_C4127(fixed_rows) && rows != n) return false;
-            return {n, 1, stride};
+        if (PYBIND11_SILENCE_MSVC_C4127(fixed_rows) && rows != n)
+            return false;
+        return {n, 1, stride};
     }
 
-    static constexpr bool show_writeable = is_eigen_dense_map<Type>::value && is_eigen_mutable_map<Type>::value;
+    static constexpr bool show_writeable
+        = is_eigen_dense_map<Type>::value && is_eigen_mutable_map<Type>::value;
     static constexpr bool show_order = is_eigen_dense_map<Type>::value;
     static constexpr bool show_c_contiguous = show_order && requires_row_major;
-    static constexpr bool show_f_contiguous = !show_c_contiguous && show_order && requires_col_major;
-
-    static constexpr auto descriptor =
-        const_name("numpy.ndarray[") + npy_format_descriptor<Scalar>::name +
-        const_name("[")  + const_name<fixed_rows>(const_name<(size_t) rows>(), const_name("m")) +
-        const_name(", ") + const_name<fixed_cols>(const_name<(size_t) cols>(), const_name("n")) +
-        const_name("]") +
-        // For a reference type (e.g. Ref<MatrixXd>) we have other constraints that might need to be
-        // satisfied: writeable=True (for a mutable reference), and, depending on the map's stride
-        // options, possibly f_contiguous or c_contiguous.  We include them in the descriptor output
-        // to provide some hint as to why a TypeError is occurring (otherwise it can be confusing to
-        // see that a function accepts a 'numpy.ndarray[float64[3,2]]' and an error message that you
-        // *gave* a numpy.ndarray of the right type and dimensions.
-        const_name<show_writeable>(", flags.writeable", "") +
-        const_name<show_c_contiguous>(", flags.c_contiguous", "") +
-        const_name<show_f_contiguous>(", flags.f_contiguous", "") +
-        const_name("]");
+    static constexpr bool show_f_contiguous
+        = !show_c_contiguous && show_order && requires_col_major;
+
+    static constexpr auto descriptor
+        = const_name("numpy.ndarray[") + npy_format_descriptor<Scalar>::name + const_name("[")
+          + const_name<fixed_rows>(const_name<(size_t) rows>(), const_name("m")) + const_name(", ")
+          + const_name<fixed_cols>(const_name<(size_t) cols>(), const_name("n")) + const_name("]")
+          +
+          // For a reference type (e.g. Ref<MatrixXd>) we have other constraints that might need to
+          // be satisfied: writeable=True (for a mutable reference), and, depending on the map's
+          // stride options, possibly f_contiguous or c_contiguous.  We include them in the
+          // descriptor output to provide some hint as to why a TypeError is occurring (otherwise
+          // it can be confusing to see that a function accepts a 'numpy.ndarray[float64[3,2]]' and
+          // an error message that you *gave* a numpy.ndarray of the right type and dimensions.
+          const_name<show_writeable>(", flags.writeable", "")
+          + const_name<show_c_contiguous>(", flags.c_contiguous", "")
+          + const_name<show_f_contiguous>(", flags.f_contiguous", "") + const_name("]");
 };
 
 // Casts an Eigen type to numpy array.  If given a base, the numpy array references the src data,
 // otherwise it'll make a copy.  writeable lets you turn off the writeable flag for the array.
-template <typename props> handle eigen_array_cast(typename props::Type const &src, handle base = handle(), bool writeable = true) {
+template <typename props>
+handle
+eigen_array_cast(typename props::Type const &src, handle base = handle(), bool writeable = true) {
     constexpr ssize_t elem_size = sizeof(typename props::Scalar);
     array a;
     if (props::vector)
-        a = array({ src.size() }, { elem_size * src.innerStride() }, src.data(), base);
+        a = array({src.size()}, {elem_size * src.innerStride()}, src.data(), base);
     else
-        a = array({ src.rows(), src.cols() }, { elem_size * src.rowStride(), elem_size * src.colStride() },
-                  src.data(), base);
+        a = array({src.rows(), src.cols()},
+                  {elem_size * src.rowStride(), elem_size * src.colStride()},
+                  src.data(),
+                  base);
 
     if (!writeable)
         array_proxy(a.ptr())->flags &= ~detail::npy_api::NPY_ARRAY_WRITEABLE_;
@@ -236,10 +264,10 @@ handle eigen_ref_array(Type &src, handle parent = none()) {
     return eigen_array_cast<props>(src, parent, !std::is_const<Type>::value);
 }
 
-// Takes a pointer to some dense, plain Eigen type, builds a capsule around it, then returns a numpy
-// array that references the encapsulated data with a python-side reference to the capsule to tie
-// its destruction to that of any dependent python objects.  Const-ness is determined by whether or
-// not the Type of the pointer given is const.
+// Takes a pointer to some dense, plain Eigen type, builds a capsule around it, then returns a
+// numpy array that references the encapsulated data with a python-side reference to the capsule to
+// tie its destruction to that of any dependent python objects.  Const-ness is determined by
+// whether or not the Type of the pointer given is const.
 template <typename props, typename Type, typename = enable_if_t<is_eigen_dense_plain<Type>::value>>
 handle eigen_encapsulate(Type *src) {
     capsule base(src, [](void *o) { delete static_cast<Type *>(o); });
@@ -248,7 +276,7 @@ handle eigen_encapsulate(Type *src) {
 
 // Type caster for regular, dense matrix types (e.g. MatrixXd), but not maps/refs/etc. of dense
 // types.
-template<typename Type>
+template <typename Type>
 struct type_caster<Type, enable_if_t<is_eigen_dense_plain<Type>::value>> {
     using Scalar = typename Type::Scalar;
     using props = EigenProps<Type>;
@@ -275,8 +303,10 @@ struct type_caster<Type, enable_if_t<is_eigen_dense_plain<Type>::value>> {
         // Allocate the new type, then build a numpy reference into it
         value = Type(fits.rows, fits.cols);
         auto ref = reinterpret_steal<array>(eigen_ref_array<props>(value));
-        if (dims == 1) ref = ref.squeeze();
-        else if (ref.ndim() == 1) buf = buf.squeeze();
+        if (dims == 1)
+            ref = ref.squeeze();
+        else if (ref.ndim() == 1)
+            buf = buf.squeeze();
 
         int result = detail::npy_api::get().PyArray_CopyInto_(ref.ptr(), buf.ptr());
 
@@ -289,7 +319,6 @@ struct type_caster<Type, enable_if_t<is_eigen_dense_plain<Type>::value>> {
     }
 
 private:
-
     // Cast implementation
     template <typename CType>
     static handle cast_impl(CType *src, return_value_policy policy, handle parent) {
@@ -312,7 +341,6 @@ struct type_caster<Type, enable_if_t<is_eigen_dense_plain<Type>::value>> {
     }
 
 public:
-
     // Normal returned non-reference, non-const value:
     static handle cast(Type &&src, return_value_policy /* policy */, handle parent) {
         return cast_impl(&src, return_value_policy::move, parent);
@@ -323,13 +351,15 @@ struct type_caster<Type, enable_if_t<is_eigen_dense_plain<Type>::value>> {
     }
     // lvalue reference return; default (automatic) becomes copy
     static handle cast(Type &src, return_value_policy policy, handle parent) {
-        if (policy == return_value_policy::automatic || policy == return_value_policy::automatic_reference)
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference)
             policy = return_value_policy::copy;
         return cast_impl(&src, policy, parent);
     }
     // const lvalue reference return; default (automatic) becomes copy
     static handle cast(const Type &src, return_value_policy policy, handle parent) {
-        if (policy == return_value_policy::automatic || policy == return_value_policy::automatic_reference)
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference)
             policy = return_value_policy::copy;
         return cast(&src, policy, parent);
     }
@@ -345,30 +375,31 @@ struct type_caster<Type, enable_if_t<is_eigen_dense_plain<Type>::value>> {
     static constexpr auto name = props::descriptor;
 
     // NOLINTNEXTLINE(google-explicit-constructor)
-    operator Type*() { return &value; }
+    operator Type *() { return &value; }
     // NOLINTNEXTLINE(google-explicit-constructor)
-    operator Type&() { return value; }
+    operator Type &() { return value; }
     // NOLINTNEXTLINE(google-explicit-constructor)
-    operator Type&&() && { return std::move(value); }
-    template <typename T> using cast_op_type = movable_cast_op_type<T>;
+    operator Type &&() && { return std::move(value); }
+    template <typename T>
+    using cast_op_type = movable_cast_op_type<T>;
 
 private:
     Type value;
 };
 
 // Base class for casting reference/map/block/etc. objects back to python.
-template <typename MapType> struct eigen_map_caster {
+template <typename MapType>
+struct eigen_map_caster {
 private:
     using props = EigenProps<MapType>;
 
 public:
-
     // Directly referencing a ref/map's data is a bit dangerous (whatever the map/ref points to has
-    // to stay around), but we'll allow it under the assumption that you know what you're doing (and
-    // have an appropriate keep_alive in place).  We return a numpy array pointing directly at the
-    // ref's data (The numpy array ends up read-only if the ref was to a const matrix type.) Note
-    // that this means you need to ensure you don't destroy the object in some other way (e.g. with
-    // an appropriate keep_alive, or with a reference to a statically allocated matrix).
+    // to stay around), but we'll allow it under the assumption that you know what you're doing
+    // (and have an appropriate keep_alive in place).  We return a numpy array pointing directly at
+    // the ref's data (The numpy array ends up read-only if the ref was to a const matrix type.)
+    // Note that this means you need to ensure you don't destroy the object in some other way (e.g.
+    // with an appropriate keep_alive, or with a reference to a statically allocated matrix).
     static handle cast(const MapType &src, return_value_policy policy, handle parent) {
         switch (policy) {
             case return_value_policy::copy:
@@ -392,43 +423,50 @@ template <typename MapType> struct eigen_map_caster {
     // you end up here if you try anyway.
     bool load(handle, bool) = delete;
     operator MapType() = delete;
-    template <typename> using cast_op_type = MapType;
+    template <typename>
+    using cast_op_type = MapType;
 };
 
 // We can return any map-like object (but can only load Refs, specialized next):
-template <typename Type> struct type_caster<Type, enable_if_t<is_eigen_dense_map<Type>::value>>
-    : eigen_map_caster<Type> {};
+template <typename Type>
+struct type_caster<Type, enable_if_t<is_eigen_dense_map<Type>::value>> : eigen_map_caster<Type> {};
 
 // Loader for Ref<...> arguments.  See the documentation for info on how to make this work without
 // copying (it requires some extra effort in many cases).
 template <typename PlainObjectType, typename StrideType>
 struct type_caster<
     Eigen::Ref<PlainObjectType, 0, StrideType>,
-    enable_if_t<is_eigen_dense_map<Eigen::Ref<PlainObjectType, 0, StrideType>>::value>
-> : public eigen_map_caster<Eigen::Ref<PlainObjectType, 0, StrideType>> {
+    enable_if_t<is_eigen_dense_map<Eigen::Ref<PlainObjectType, 0, StrideType>>::value>>
+    : public eigen_map_caster<Eigen::Ref<PlainObjectType, 0, StrideType>> {
 private:
     using Type = Eigen::Ref<PlainObjectType, 0, StrideType>;
     using props = EigenProps<Type>;
     using Scalar = typename props::Scalar;
     using MapType = Eigen::Map<PlainObjectType, 0, StrideType>;
-    using Array = array_t<Scalar, array::forcecast |
-                ((props::row_major ? props::inner_stride : props::outer_stride) == 1 ? array::c_style :
-                 (props::row_major ? props::outer_stride : props::inner_stride) == 1 ? array::f_style : 0)>;
+    using Array
+        = array_t<Scalar,
+                  array::forcecast
+                      | ((props::row_major ? props::inner_stride : props::outer_stride) == 1
+                             ? array::c_style
+                         : (props::row_major ? props::outer_stride : props::inner_stride) == 1
+                             ? array::f_style
+                             : 0)>;
     static constexpr bool need_writeable = is_eigen_mutable_map<Type>::value;
     // Delay construction (these have no default constructor)
     std::unique_ptr<MapType> map;
     std::unique_ptr<Type> ref;
     // Our array.  When possible, this is just a numpy array pointing to the source data, but
-    // sometimes we can't avoid copying (e.g. input is not a numpy array at all, has an incompatible
-    // layout, or is an array of a type that needs to be converted).  Using a numpy temporary
-    // (rather than an Eigen temporary) saves an extra copy when we need both type conversion and
-    // storage order conversion.  (Note that we refuse to use this temporary copy when loading an
-    // argument for a Ref<M> with M non-const, i.e. a read-write reference).
+    // sometimes we can't avoid copying (e.g. input is not a numpy array at all, has an
+    // incompatible layout, or is an array of a type that needs to be converted).  Using a numpy
+    // temporary (rather than an Eigen temporary) saves an extra copy when we need both type
+    // conversion and storage order conversion.  (Note that we refuse to use this temporary copy
+    // when loading an argument for a Ref<M> with M non-const, i.e. a read-write reference).
     Array copy_or_ref;
+
 public:
     bool load(handle src, bool convert) {
-        // First check whether what we have is already an array of the right type.  If not, we can't
-        // avoid a copy (because the copy is also going to do type conversion).
+        // First check whether what we have is already an array of the right type.  If not, we
+        // can't avoid a copy (because the copy is also going to do type conversion).
         bool need_copy = !isinstance<Array>(src);
 
         EigenConformable<props::row_major> fits;
@@ -439,13 +477,13 @@ struct type_caster<
 
             if (aref && (!need_writeable || aref.writeable())) {
                 fits = props::conformable(aref);
-                if (!fits) return false; // Incompatible dimensions
+                if (!fits)
+                    return false; // Incompatible dimensions
                 if (!fits.template stride_compatible<props>())
                     need_copy = true;
                 else
                     copy_or_ref = std::move(aref);
-            }
-            else {
+            } else {
                 need_copy = true;
             }
         }
@@ -454,10 +492,12 @@ struct type_caster<
             // We need to copy: If we need a mutable reference, or we're not supposed to convert
             // (either because we're in the no-convert overload pass, or because we're explicitly
             // instructed not to copy (via `py::arg().noconvert()`) we have to fail loading.
-            if (!convert || need_writeable) return false;
+            if (!convert || need_writeable)
+                return false;
 
             Array copy = Array::ensure(src);
-            if (!copy) return false;
+            if (!copy)
+                return false;
             fits = props::conformable(copy);
             if (!fits || !fits.template stride_compatible<props>())
                 return false;
@@ -466,54 +506,76 @@ struct type_caster<
         }
 
         ref.reset();
-        map.reset(new MapType(data(copy_or_ref), fits.rows, fits.cols, make_stride(fits.stride.outer(), fits.stride.inner())));
+        map.reset(new MapType(data(copy_or_ref),
+                              fits.rows,
+                              fits.cols,
+                              make_stride(fits.stride.outer(), fits.stride.inner())));
         ref.reset(new Type(*map));
 
         return true;
     }
 
     // NOLINTNEXTLINE(google-explicit-constructor)
-    operator Type*() { return ref.get(); }
+    operator Type *() { return ref.get(); }
     // NOLINTNEXTLINE(google-explicit-constructor)
-    operator Type&() { return *ref; }
-    template <typename _T> using cast_op_type = pybind11::detail::cast_op_type<_T>;
+    operator Type &() { return *ref; }
+    template <typename _T>
+    using cast_op_type = pybind11::detail::cast_op_type<_T>;
 
 private:
     template <typename T = Type, enable_if_t<is_eigen_mutable_map<T>::value, int> = 0>
-    Scalar *data(Array &a) { return a.mutable_data(); }
+    Scalar *data(Array &a) {
+        return a.mutable_data();
+    }
 
     template <typename T = Type, enable_if_t<!is_eigen_mutable_map<T>::value, int> = 0>
-    const Scalar *data(Array &a) { return a.data(); }
+    const Scalar *data(Array &a) {
+        return a.data();
+    }
 
     // Attempt to figure out a constructor of `Stride` that will work.
     // If both strides are fixed, use a default constructor:
-    template <typename S> using stride_ctor_default = bool_constant<
-        S::InnerStrideAtCompileTime != Eigen::Dynamic && S::OuterStrideAtCompileTime != Eigen::Dynamic &&
-        std::is_default_constructible<S>::value>;
+    template <typename S>
+    using stride_ctor_default = bool_constant<S::InnerStrideAtCompileTime != Eigen::Dynamic
+                                              && S::OuterStrideAtCompileTime != Eigen::Dynamic
+                                              && std::is_default_constructible<S>::value>;
     // Otherwise, if there is a two-index constructor, assume it is (outer,inner) like
     // Eigen::Stride, and use it:
-    template <typename S> using stride_ctor_dual = bool_constant<
-        !stride_ctor_default<S>::value && std::is_constructible<S, EigenIndex, EigenIndex>::value>;
+    template <typename S>
+    using stride_ctor_dual
+        = bool_constant<!stride_ctor_default<S>::value
+                        && std::is_constructible<S, EigenIndex, EigenIndex>::value>;
     // Otherwise, if there is a one-index constructor, and just one of the strides is dynamic, use
     // it (passing whichever stride is dynamic).
-    template <typename S> using stride_ctor_outer = bool_constant<
-        !any_of<stride_ctor_default<S>, stride_ctor_dual<S>>::value &&
-        S::OuterStrideAtCompileTime == Eigen::Dynamic && S::InnerStrideAtCompileTime != Eigen::Dynamic &&
-        std::is_constructible<S, EigenIndex>::value>;
-    template <typename S> using stride_ctor_inner = bool_constant<
-        !any_of<stride_ctor_default<S>, stride_ctor_dual<S>>::value &&
-        S::InnerStrideAtCompileTime == Eigen::Dynamic && S::OuterStrideAtCompileTime != Eigen::Dynamic &&
-        std::is_constructible<S, EigenIndex>::value>;
+    template <typename S>
+    using stride_ctor_outer
+        = bool_constant<!any_of<stride_ctor_default<S>, stride_ctor_dual<S>>::value
+                        && S::OuterStrideAtCompileTime == Eigen::Dynamic
+                        && S::InnerStrideAtCompileTime != Eigen::Dynamic
+                        && std::is_constructible<S, EigenIndex>::value>;
+    template <typename S>
+    using stride_ctor_inner
+        = bool_constant<!any_of<stride_ctor_default<S>, stride_ctor_dual<S>>::value
+                        && S::InnerStrideAtCompileTime == Eigen::Dynamic
+                        && S::OuterStrideAtCompileTime != Eigen::Dynamic
+                        && std::is_constructible<S, EigenIndex>::value>;
 
     template <typename S = StrideType, enable_if_t<stride_ctor_default<S>::value, int> = 0>
-    static S make_stride(EigenIndex, EigenIndex) { return S(); }
+    static S make_stride(EigenIndex, EigenIndex) {
+        return S();
+    }
     template <typename S = StrideType, enable_if_t<stride_ctor_dual<S>::value, int> = 0>
-    static S make_stride(EigenIndex outer, EigenIndex inner) { return S(outer, inner); }
+    static S make_stride(EigenIndex outer, EigenIndex inner) {
+        return S(outer, inner);
+    }
     template <typename S = StrideType, enable_if_t<stride_ctor_outer<S>::value, int> = 0>
-    static S make_stride(EigenIndex outer, EigenIndex) { return S(outer); }
+    static S make_stride(EigenIndex outer, EigenIndex) {
+        return S(outer);
+    }
     template <typename S = StrideType, enable_if_t<stride_ctor_inner<S>::value, int> = 0>
-    static S make_stride(EigenIndex, EigenIndex inner) { return S(inner); }
-
+    static S make_stride(EigenIndex, EigenIndex inner) {
+        return S(inner);
+    }
 };
 
 // type_caster for special matrix types (e.g. DiagonalMatrix), which are EigenBase, but not
@@ -523,14 +585,18 @@ struct type_caster<
 template <typename Type>
 struct type_caster<Type, enable_if_t<is_eigen_other<Type>::value>> {
 protected:
-    using Matrix = Eigen::Matrix<typename Type::Scalar, Type::RowsAtCompileTime, Type::ColsAtCompileTime>;
+    using Matrix
+        = Eigen::Matrix<typename Type::Scalar, Type::RowsAtCompileTime, Type::ColsAtCompileTime>;
     using props = EigenProps<Matrix>;
+
 public:
     static handle cast(const Type &src, return_value_policy /* policy */, handle /* parent */) {
         handle h = eigen_encapsulate<props>(new Matrix(src));
         return h;
     }
-    static handle cast(const Type *src, return_value_policy policy, handle parent) { return cast(*src, policy, parent); }
+    static handle cast(const Type *src, return_value_policy policy, handle parent) {
+        return cast(*src, policy, parent);
+    }
 
     static constexpr auto name = props::descriptor;
 
@@ -539,10 +605,11 @@ struct type_caster<Type, enable_if_t<is_eigen_other<Type>::value>> {
     // you end up here if you try anyway.
     bool load(handle, bool) = delete;
     operator Type() = delete;
-    template <typename> using cast_op_type = Type;
+    template <typename>
+    using cast_op_type = Type;
 };
 
-template<typename Type>
+template <typename Type>
 struct type_caster<Type, enable_if_t<is_eigen_sparse<Type>::value>> {
     using Scalar = typename Type::Scalar;
     using StorageIndex = remove_reference_t<decltype(*std::declval<Type>().outerIndexPtr())>;
@@ -555,8 +622,7 @@ struct type_caster<Type, enable_if_t<is_eigen_sparse<Type>::value>> {
 
         auto obj = reinterpret_borrow<object>(src);
         object sparse_module = module_::import("scipy.sparse");
-        object matrix_type = sparse_module.attr(
-            rowMajor ? "csr_matrix" : "csc_matrix");
+        object matrix_type = sparse_module.attr(rowMajor ? "csr_matrix" : "csc_matrix");
 
         if (!type::handle_of(obj).is(matrix_type)) {
             try {
@@ -576,32 +642,36 @@ struct type_caster<Type, enable_if_t<is_eigen_sparse<Type>::value>> {
             return false;
 
         value = EigenMapSparseMatrix<Scalar,
-                                     Type::Flags & (Eigen::RowMajor | Eigen::ColMajor),
-                                     StorageIndex>(
-            shape[0].cast<Index>(), shape[1].cast<Index>(), nnz,
-            outerIndices.mutable_data(), innerIndices.mutable_data(), values.mutable_data());
+                                     Type::Flags &(Eigen::RowMajor | Eigen::ColMajor),
+                                     StorageIndex>(shape[0].cast<Index>(),
+                                                   shape[1].cast<Index>(),
+                                                   nnz,
+                                                   outerIndices.mutable_data(),
+                                                   innerIndices.mutable_data(),
+                                                   values.mutable_data());
 
         return true;
     }
 
     static handle cast(const Type &src, return_value_policy /* policy */, handle /* parent */) {
-        const_cast<Type&>(src).makeCompressed();
+        const_cast<Type &>(src).makeCompressed();
 
-        object matrix_type = module_::import("scipy.sparse").attr(
-            rowMajor ? "csr_matrix" : "csc_matrix");
+        object matrix_type
+            = module_::import("scipy.sparse").attr(rowMajor ? "csr_matrix" : "csc_matrix");
 
         array data(src.nonZeros(), src.valuePtr());
         array outerIndices((rowMajor ? src.rows() : src.cols()) + 1, src.outerIndexPtr());
         array innerIndices(src.nonZeros(), src.innerIndexPtr());
 
-        return matrix_type(
-            std::make_tuple(data, innerIndices, outerIndices),
-            std::make_pair(src.rows(), src.cols())
-        ).release();
+        return matrix_type(std::make_tuple(data, innerIndices, outerIndices),
+                           std::make_pair(src.rows(), src.cols()))
+            .release();
     }
 
-    PYBIND11_TYPE_CASTER(Type, const_name<(Type::IsRowMajor) != 0>("scipy.sparse.csr_matrix[", "scipy.sparse.csc_matrix[")
-            + npy_format_descriptor<Scalar>::name + const_name("]"));
+    PYBIND11_TYPE_CASTER(Type,
+                         const_name<(Type::IsRowMajor) != 0>("scipy.sparse.csr_matrix[",
+                                                             "scipy.sparse.csc_matrix[")
+                             + npy_format_descriptor<Scalar>::name + const_name("]"));
 };
 
 PYBIND11_NAMESPACE_END(detail)
diff --git a/include/pybind11/embed.h b/include/pybind11/embed.h
index 9ab1ce9c0a..ab11bcb931 100644
--- a/include/pybind11/embed.h
+++ b/include/pybind11/embed.h
@@ -16,21 +16,17 @@
 #include <vector>
 
 #if defined(PYPY_VERSION)
-#  error Embedding the interpreter is not supported with PyPy
+#    error Embedding the interpreter is not supported with PyPy
 #endif
 
 #if PY_MAJOR_VERSION >= 3
-#  define PYBIND11_EMBEDDED_MODULE_IMPL(name)            \
-      extern "C" PyObject *pybind11_init_impl_##name();  \
-      extern "C" PyObject *pybind11_init_impl_##name() { \
-          return pybind11_init_wrapper_##name();         \
-      }
+#    define PYBIND11_EMBEDDED_MODULE_IMPL(name)                                                   \
+        extern "C" PyObject *pybind11_init_impl_##name();                                         \
+        extern "C" PyObject *pybind11_init_impl_##name() { return pybind11_init_wrapper_##name(); }
 #else
-#  define PYBIND11_EMBEDDED_MODULE_IMPL(name)            \
-      extern "C" void pybind11_init_impl_##name();       \
-      extern "C" void pybind11_init_impl_##name() {      \
-          pybind11_init_wrapper_##name();                \
-      }
+#    define PYBIND11_EMBEDDED_MODULE_IMPL(name)                                                   \
+        extern "C" void pybind11_init_impl_##name();                                              \
+        extern "C" void pybind11_init_impl_##name() { pybind11_init_wrapper_##name(); }
 #endif
 
 /** \rst
@@ -72,7 +68,7 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 /// Python 2.7/3.x compatible version of `PyImport_AppendInittab` and error checks.
 struct embedded_module {
 #if PY_MAJOR_VERSION >= 3
-    using init_t = PyObject *(*)();
+    using init_t = PyObject *(*) ();
 #else
     using init_t = void (*)();
 #endif
@@ -104,10 +100,10 @@ inline wchar_t *widen_chars(const char *safe_arg) {
     wchar_t *widened_arg = nullptr;
 
 // warning C4996: 'mbstowcs': This function or variable may be unsafe.
-#if defined(_MSC_VER)
-#pragma warning(push)
-#pragma warning(disable:4996)
-#endif
+#    if defined(_MSC_VER)
+#        pragma warning(push)
+#        pragma warning(disable : 4996)
+#    endif
 
 #    if defined(HAVE_BROKEN_MBSTOWCS) && HAVE_BROKEN_MBSTOWCS
     size_t count = std::strlen(safe_arg);
@@ -119,9 +115,9 @@ inline wchar_t *widen_chars(const char *safe_arg) {
         std::mbstowcs(widened_arg, safe_arg, count + 1);
     }
 
-#if defined(_MSC_VER)
-#pragma warning(pop)
-#endif
+#    if defined(_MSC_VER)
+#        pragma warning(pop)
+#    endif
 
 #endif
     return widened_arg;
@@ -154,7 +150,7 @@ inline void set_interpreter_argv(int argc, const char *const *argv, bool add_pro
         widened_argv[ii] = widened_argv_entries.back().get();
     }
 
-    auto pysys_argv = widened_argv.get();
+    auto *pysys_argv = widened_argv.get();
 #else
     // python 2.x
     std::vector<std::string> strings{safe_argv, safe_argv + argv_size};
diff --git a/include/pybind11/eval.h b/include/pybind11/eval.h
index 4248551e9b..4508feb740 100644
--- a/include/pybind11/eval.h
+++ b/include/pybind11/eval.h
@@ -11,24 +11,24 @@
 
 #pragma once
 
-#include <utility>
-
 #include "pybind11.h"
 
+#include <utility>
+
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 inline void ensure_builtins_in_globals(object &global) {
-    #if defined(PYPY_VERSION) || PY_VERSION_HEX < 0x03080000
-        // Running exec and eval on Python 2 and 3 adds `builtins` module under
-        // `__builtins__` key to globals if not yet present.
-        // Python 3.8 made PyRun_String behave similarly. Let's also do that for
-        // older versions, for consistency. This was missing from PyPy3.8 7.3.7.
-        if (!global.contains("__builtins__"))
-            global["__builtins__"] = module_::import(PYBIND11_BUILTINS_MODULE);
-    #else
-        (void) global;
-    #endif
+#if defined(PYPY_VERSION) || PY_VERSION_HEX < 0x03080000
+    // Running exec and eval on Python 2 and 3 adds `builtins` module under
+    // `__builtins__` key to globals if not yet present.
+    // Python 3.8 made PyRun_String behave similarly. Let's also do that for
+    // older versions, for consistency. This was missing from PyPy3.8 7.3.7.
+    if (!global.contains("__builtins__"))
+        global["__builtins__"] = module_::import(PYBIND11_BUILTINS_MODULE);
+#else
+    (void) global;
+#endif
 }
 
 PYBIND11_NAMESPACE_END(detail)
@@ -57,10 +57,17 @@ object eval(const str &expr, object global = globals(), object local = object())
 
     int start = 0;
     switch (mode) {
-        case eval_expr:             start = Py_eval_input;   break;
-        case eval_single_statement: start = Py_single_input; break;
-        case eval_statements:       start = Py_file_input;   break;
-        default: pybind11_fail("invalid evaluation mode");
+        case eval_expr:
+            start = Py_eval_input;
+            break;
+        case eval_single_statement:
+            start = Py_single_input;
+            break;
+        case eval_statements:
+            start = Py_file_input;
+            break;
+        default:
+            pybind11_fail("invalid evaluation mode");
     }
 
     PyObject *result = PyRun_String(buffer.c_str(), start, global.ptr(), local.ptr());
@@ -72,8 +79,7 @@ object eval(const str &expr, object global = globals(), object local = object())
 template <eval_mode mode = eval_expr, size_t N>
 object eval(const char (&s)[N], object global = globals(), object local = object()) {
     /* Support raw string literals by removing common leading whitespace */
-    auto expr = (s[0] == '\n') ? str(module_::import("textwrap").attr("dedent")(s))
-                               : str(s);
+    auto expr = (s[0] == '\n') ? str(module_::import("textwrap").attr("dedent")(s)) : str(s);
     return eval<mode>(expr, global, local);
 }
 
@@ -109,28 +115,34 @@ object eval_file(str fname, object global = globals(), object local = object())
 
     int start = 0;
     switch (mode) {
-        case eval_expr:             start = Py_eval_input;   break;
-        case eval_single_statement: start = Py_single_input; break;
-        case eval_statements:       start = Py_file_input;   break;
-        default: pybind11_fail("invalid evaluation mode");
+        case eval_expr:
+            start = Py_eval_input;
+            break;
+        case eval_single_statement:
+            start = Py_single_input;
+            break;
+        case eval_statements:
+            start = Py_file_input;
+            break;
+        default:
+            pybind11_fail("invalid evaluation mode");
     }
 
     int closeFile = 1;
     std::string fname_str = (std::string) fname;
-#if PY_VERSION_HEX >= 0x03040000
+#    if PY_VERSION_HEX >= 0x03040000
     FILE *f = _Py_fopen_obj(fname.ptr(), "r");
-#elif PY_VERSION_HEX >= 0x03000000
+#    elif PY_VERSION_HEX >= 0x03000000
     FILE *f = _Py_fopen(fname.ptr(), "r");
-#else
+#    else
     /* No unicode support in open() :( */
-    auto fobj = reinterpret_steal<object>(PyFile_FromString(
-        const_cast<char *>(fname_str.c_str()),
-        const_cast<char*>("r")));
+    auto fobj = reinterpret_steal<object>(
+        PyFile_FromString(const_cast<char *>(fname_str.c_str()), const_cast<char *>("r")));
     FILE *f = nullptr;
     if (fobj)
         f = PyFile_AsFile(fobj.ptr());
     closeFile = 0;
-#endif
+#    endif
     if (!f) {
         PyErr_Clear();
         pybind11_fail("File \"" + fname_str + "\" could not be opened!");
@@ -139,20 +151,19 @@ object eval_file(str fname, object global = globals(), object local = object())
     // In Python2, this should be encoded by getfilesystemencoding.
     // We don't boher setting it since Python2 is past EOL anyway.
     // See PR#3233
-#if PY_VERSION_HEX >= 0x03000000
+#    if PY_VERSION_HEX >= 0x03000000
     if (!global.contains("__file__")) {
         global["__file__"] = std::move(fname);
     }
-#endif
+#    endif
 
-#if PY_VERSION_HEX < 0x03000000 && defined(PYPY_VERSION)
-    PyObject *result = PyRun_File(f, fname_str.c_str(), start, global.ptr(),
-                                  local.ptr());
+#    if PY_VERSION_HEX < 0x03000000 && defined(PYPY_VERSION)
+    PyObject *result = PyRun_File(f, fname_str.c_str(), start, global.ptr(), local.ptr());
     (void) closeFile;
-#else
-    PyObject *result = PyRun_FileEx(f, fname_str.c_str(), start, global.ptr(),
-                                    local.ptr(), closeFile);
-#endif
+#    else
+    PyObject *result
+        = PyRun_FileEx(f, fname_str.c_str(), start, global.ptr(), local.ptr(), closeFile);
+#    endif
 
     if (!result)
         throw error_already_set();
diff --git a/include/pybind11/functional.h b/include/pybind11/functional.h
index 7912aef175..ef00a06500 100644
--- a/include/pybind11/functional.h
+++ b/include/pybind11/functional.h
@@ -10,6 +10,7 @@
 #pragma once
 
 #include "pybind11.h"
+
 #include <functional>
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
@@ -19,13 +20,14 @@ template <typename Return, typename... Args>
 struct type_caster<std::function<Return(Args...)>> {
     using type = std::function<Return(Args...)>;
     using retval_type = conditional_t<std::is_same<Return, void>::value, void_type, Return>;
-    using function_type = Return (*) (Args...);
+    using function_type = Return (*)(Args...);
 
 public:
     bool load(handle src, bool convert) {
         if (src.is_none()) {
             // Defer accepting None to other overloads (if we aren't in convert mode):
-            if (!convert) return false;
+            if (!convert)
+                return false;
             return true;
         }
 
@@ -43,10 +45,10 @@ struct type_caster<std::function<Return(Args...)>> {
            captured variables), in which case the roundtrip can be avoided.
          */
         if (auto cfunc = func.cpp_function()) {
-            auto cfunc_self = PyCFunction_GET_SELF(cfunc.ptr());
+            auto *cfunc_self = PyCFunction_GET_SELF(cfunc.ptr());
             if (isinstance<capsule>(cfunc_self)) {
                 auto c = reinterpret_borrow<capsule>(cfunc_self);
-                auto rec = (function_record *) c;
+                auto *rec = (function_record *) c;
 
                 while (rec != nullptr) {
                     if (rec->is_stateless
@@ -73,7 +75,9 @@ struct type_caster<std::function<Return(Args...)>> {
             // This triggers a syntax error under very special conditions (very weird indeed).
             explicit
 #endif
-            func_handle(function &&f_) noexcept : f(std::move(f_)) {}
+                func_handle(function &&f_) noexcept
+                : f(std::move(f_)) {
+            }
             func_handle(const func_handle &f_) { operator=(f_); }
             func_handle &operator=(const func_handle &f_) {
                 gil_scoped_acquire acq;
@@ -113,8 +117,10 @@ struct type_caster<std::function<Return(Args...)>> {
         return cpp_function(std::forward<Func>(f_), policy).release();
     }
 
-    PYBIND11_TYPE_CASTER(type, const_name("Callable[[") + concat(make_caster<Args>::name...) + const_name("], ")
-                               + make_caster<retval_type>::name + const_name("]"));
+    PYBIND11_TYPE_CASTER(type,
+                         const_name("Callable[[") + concat(make_caster<Args>::name...)
+                             + const_name("], ") + make_caster<retval_type>::name
+                             + const_name("]"));
 };
 
 PYBIND11_NAMESPACE_END(detail)
diff --git a/include/pybind11/gil.h b/include/pybind11/gil.h
index b73aaa3f54..55a529d587 100644
--- a/include/pybind11/gil.h
+++ b/include/pybind11/gil.h
@@ -14,7 +14,6 @@
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 
-
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 // forward declarations
@@ -22,7 +21,6 @@ PyThreadState *get_thread_state_unchecked();
 
 PYBIND11_NAMESPACE_END(detail)
 
-
 #if defined(WITH_THREAD) && !defined(PYPY_VERSION)
 
 /* The functions below essentially reproduce the PyGILState_* API using a RAII
@@ -64,10 +62,10 @@ class gil_scoped_acquire {
 
         if (!tstate) {
             tstate = PyThreadState_New(internals.istate);
-            #if !defined(NDEBUG)
-                if (!tstate)
-                    pybind11_fail("scoped_acquire: could not create thread state!");
-            #endif
+#    if !defined(NDEBUG)
+            if (!tstate)
+                pybind11_fail("scoped_acquire: could not create thread state!");
+#    endif
             tstate->gilstate_counter = 0;
             PYBIND11_TLS_REPLACE_VALUE(internals.tstate, tstate);
         } else {
@@ -81,23 +79,21 @@ class gil_scoped_acquire {
         inc_ref();
     }
 
-    void inc_ref() {
-        ++tstate->gilstate_counter;
-    }
+    void inc_ref() { ++tstate->gilstate_counter; }
 
     PYBIND11_NOINLINE void dec_ref() {
         --tstate->gilstate_counter;
-        #if !defined(NDEBUG)
-            if (detail::get_thread_state_unchecked() != tstate)
-                pybind11_fail("scoped_acquire::dec_ref(): thread state must be current!");
-            if (tstate->gilstate_counter < 0)
-                pybind11_fail("scoped_acquire::dec_ref(): reference count underflow!");
-        #endif
+#    if !defined(NDEBUG)
+        if (detail::get_thread_state_unchecked() != tstate)
+            pybind11_fail("scoped_acquire::dec_ref(): thread state must be current!");
+        if (tstate->gilstate_counter < 0)
+            pybind11_fail("scoped_acquire::dec_ref(): reference count underflow!");
+#    endif
         if (tstate->gilstate_counter == 0) {
-            #if !defined(NDEBUG)
-                if (!release)
-                    pybind11_fail("scoped_acquire::dec_ref(): internal error!");
-            #endif
+#    if !defined(NDEBUG)
+            if (!release)
+                pybind11_fail("scoped_acquire::dec_ref(): internal error!");
+#    endif
             PyThreadState_Clear(tstate);
             if (active)
                 PyThreadState_DeleteCurrent();
@@ -111,15 +107,14 @@ class gil_scoped_acquire {
     /// could be shutting down when this is called, as thread deletion is not
     /// allowed during shutdown. Check _Py_IsFinalizing() on Python 3.7+, and
     /// protect subsequent code.
-    PYBIND11_NOINLINE void disarm() {
-        active = false;
-    }
+    PYBIND11_NOINLINE void disarm() { active = false; }
 
     PYBIND11_NOINLINE ~gil_scoped_acquire() {
         dec_ref();
         if (release)
-           PyEval_SaveThread();
+            PyEval_SaveThread();
     }
+
 private:
     PyThreadState *tstate = nullptr;
     bool release = true;
@@ -135,6 +130,8 @@ class gil_scoped_release {
         auto &internals = detail::get_internals();
         tstate = PyEval_SaveThread();
         if (disassoc) {
+            // Python >= 3.7 can remove this, it's an int before 3.7
+            // NOLINTNEXTLINE(readability-qualified-auto)
             auto key = internals.tstate;
             PYBIND11_TLS_DELETE_VALUE(key);
         }
@@ -145,9 +142,7 @@ class gil_scoped_release {
     /// could be shutting down when this is called, as thread deletion is not
     /// allowed during shutdown. Check _Py_IsFinalizing() on Python 3.7+, and
     /// protect subsequent code.
-    PYBIND11_NOINLINE void disarm() {
-        active = false;
-    }
+    PYBIND11_NOINLINE void disarm() { active = false; }
 
     ~gil_scoped_release() {
         if (!tstate)
@@ -156,10 +151,13 @@ class gil_scoped_release {
         if (active)
             PyEval_RestoreThread(tstate);
         if (disassoc) {
+            // Python >= 3.7 can remove this, it's an int before 3.7
+            // NOLINTNEXTLINE(readability-qualified-auto)
             auto key = detail::get_internals().tstate;
             PYBIND11_TLS_REPLACE_VALUE(key, tstate);
         }
     }
+
 private:
     PyThreadState *tstate;
     bool disassoc;
@@ -168,6 +166,7 @@ class gil_scoped_release {
 #elif defined(PYPY_VERSION)
 class gil_scoped_acquire {
     PyGILState_STATE state;
+
 public:
     gil_scoped_acquire() { state = PyGILState_Ensure(); }
     ~gil_scoped_acquire() { PyGILState_Release(state); }
@@ -176,6 +175,7 @@ class gil_scoped_acquire {
 
 class gil_scoped_release {
     PyThreadState *state;
+
 public:
     gil_scoped_release() { state = PyEval_SaveThread(); }
     ~gil_scoped_release() { PyEval_RestoreThread(state); }
diff --git a/include/pybind11/iostream.h b/include/pybind11/iostream.h
index 95449a07ba..86469b803b 100644
--- a/include/pybind11/iostream.h
+++ b/include/pybind11/iostream.h
@@ -58,29 +58,21 @@ class pythonbuf : public std::streambuf {
     size_t utf8_remainder() const {
         const auto rbase = std::reverse_iterator<char *>(pbase());
         const auto rpptr = std::reverse_iterator<char *>(pptr());
-        auto is_ascii = [](char c) {
-            return (static_cast<unsigned char>(c) & 0x80) == 0x00;
-        };
-        auto is_leading = [](char c) {
-            return (static_cast<unsigned char>(c) & 0xC0) == 0xC0;
-        };
-        auto is_leading_2b = [](char c) {
-            return static_cast<unsigned char>(c) <= 0xDF;
-        };
-        auto is_leading_3b = [](char c) {
-            return static_cast<unsigned char>(c) <= 0xEF;
-        };
+        auto is_ascii = [](char c) { return (static_cast<unsigned char>(c) & 0x80) == 0x00; };
+        auto is_leading = [](char c) { return (static_cast<unsigned char>(c) & 0xC0) == 0xC0; };
+        auto is_leading_2b = [](char c) { return static_cast<unsigned char>(c) <= 0xDF; };
+        auto is_leading_3b = [](char c) { return static_cast<unsigned char>(c) <= 0xEF; };
         // If the last character is ASCII, there are no incomplete code points
         if (is_ascii(*rpptr))
             return 0;
         // Otherwise, work back from the end of the buffer and find the first
         // UTF-8 leading byte
-        const auto rpend   = rbase - rpptr >= 3 ? rpptr + 3 : rbase;
+        const auto rpend = rbase - rpptr >= 3 ? rpptr + 3 : rbase;
         const auto leading = std::find_if(rpptr, rpend, is_leading);
         if (leading == rbase)
             return 0;
-        const auto dist    = static_cast<size_t>(leading - rpptr);
-        size_t remainder   = 0;
+        const auto dist = static_cast<size_t>(leading - rpptr);
+        size_t remainder = 0;
 
         if (dist == 0)
             remainder = 1; // 1-byte code point is impossible
@@ -100,7 +92,7 @@ class pythonbuf : public std::streambuf {
         if (pbase() != pptr()) { // If buffer is not empty
             gil_scoped_acquire tmp;
             // This subtraction cannot be negative, so dropping the sign.
-            auto size        = static_cast<size_t>(pptr() - pbase());
+            auto size = static_cast<size_t>(pptr() - pbase());
             size_t remainder = utf8_remainder();
 
             if (size > remainder) {
@@ -118,9 +110,7 @@ class pythonbuf : public std::streambuf {
         return 0;
     }
 
-    int sync() override {
-        return _sync();
-    }
+    int sync() override { return _sync(); }
 
 public:
     explicit pythonbuf(const object &pyostream, size_t buffer_size = 1024)
@@ -129,17 +119,14 @@ class pythonbuf : public std::streambuf {
         setp(d_buffer.get(), d_buffer.get() + buf_size - 1);
     }
 
-    pythonbuf(pythonbuf&&) = default;
+    pythonbuf(pythonbuf &&) = default;
 
     /// Sync before destroy
-    ~pythonbuf() override {
-        _sync();
-    }
+    ~pythonbuf() override { _sync(); }
 };
 
 PYBIND11_NAMESPACE_END(detail)
 
-
 /** \rst
     This a move-only guard that redirects output.
 
@@ -178,9 +165,7 @@ class scoped_ostream_redirect {
         old = costream.rdbuf(&buffer);
     }
 
-    ~scoped_ostream_redirect() {
-        costream.rdbuf(old);
-    }
+    ~scoped_ostream_redirect() { costream.rdbuf(old); }
 
     scoped_ostream_redirect(const scoped_ostream_redirect &) = delete;
     scoped_ostream_redirect(scoped_ostream_redirect &&other) = default;
@@ -188,7 +173,6 @@ class scoped_ostream_redirect {
     scoped_ostream_redirect &operator=(scoped_ostream_redirect &&) = delete;
 };
 
-
 /** \rst
     Like `scoped_ostream_redirect`, but redirects cerr by default. This class
     is provided primary to make ``py::call_guard`` easier to make.
@@ -208,7 +192,6 @@ class scoped_estream_redirect : public scoped_ostream_redirect {
         : scoped_ostream_redirect(costream, pyostream) {}
 };
 
-
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 // Class to redirect output as a context manager. C++ backend.
diff --git a/include/pybind11/numpy.h b/include/pybind11/numpy.h
index 95a743acec..70e9e00f84 100644
--- a/include/pybind11/numpy.h
+++ b/include/pybind11/numpy.h
@@ -11,19 +11,20 @@
 
 #include "pybind11.h"
 #include "complex.h"
-#include <numeric>
+
 #include <algorithm>
 #include <array>
 #include <cstdint>
 #include <cstdlib>
 #include <cstring>
+#include <functional>
+#include <numeric>
 #include <sstream>
 #include <string>
-#include <functional>
 #include <type_traits>
+#include <typeindex>
 #include <utility>
 #include <vector>
-#include <typeindex>
 
 /* This will be true on all flat address space platforms and allows us to reduce the
    whole npy_intp / ssize_t / Py_intptr_t business down to just ssize_t for all size
@@ -39,13 +40,16 @@ class array; // Forward declaration
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 
-template <> struct handle_type_name<array> { static constexpr auto name = const_name("numpy.ndarray"); };
+template <>
+struct handle_type_name<array> {
+    static constexpr auto name = const_name("numpy.ndarray");
+};
 
-template <typename type, typename SFINAE = void> struct npy_format_descriptor;
+template <typename type, typename SFINAE = void>
+struct npy_format_descriptor;
 
 struct PyArrayDescr_Proxy {
-    PyObject_HEAD
-    PyObject *typeobj;
+    PyObject_HEAD PyObject *typeobj;
     char kind;
     char type;
     char byteorder;
@@ -59,8 +63,7 @@ struct PyArrayDescr_Proxy {
 };
 
 struct PyArray_Proxy {
-    PyObject_HEAD
-    char *data;
+    PyObject_HEAD char *data;
     int nd;
     ssize_t *dimensions;
     ssize_t *strides;
@@ -70,22 +73,21 @@ struct PyArray_Proxy {
 };
 
 struct PyVoidScalarObject_Proxy {
-    PyObject_VAR_HEAD
-    char *obval;
+    PyObject_VAR_HEAD char *obval;
     PyArrayDescr_Proxy *descr;
     int flags;
     PyObject *base;
 };
 
 struct numpy_type_info {
-    PyObject* dtype_ptr;
+    PyObject *dtype_ptr;
     std::string format_str;
 };
 
 struct numpy_internals {
     std::unordered_map<std::type_index, numpy_type_info> registered_dtypes;
 
-    numpy_type_info *get_type_info(const std::type_info& tinfo, bool throw_if_missing = true) {
+    numpy_type_info *get_type_info(const std::type_info &tinfo, bool throw_if_missing = true) {
         auto it = registered_dtypes.find(std::type_index(tinfo));
         if (it != registered_dtypes.end())
             return &(it->second);
@@ -94,27 +96,33 @@ struct numpy_internals {
         return nullptr;
     }
 
-    template<typename T> numpy_type_info *get_type_info(bool throw_if_missing = true) {
+    template <typename T>
+    numpy_type_info *get_type_info(bool throw_if_missing = true) {
         return get_type_info(typeid(typename std::remove_cv<T>::type), throw_if_missing);
     }
 };
 
-PYBIND11_NOINLINE void load_numpy_internals(numpy_internals* &ptr) {
+PYBIND11_NOINLINE void load_numpy_internals(numpy_internals *&ptr) {
     ptr = &get_or_create_shared_data<numpy_internals>("_numpy_internals");
 }
 
-inline numpy_internals& get_numpy_internals() {
-    static numpy_internals* ptr = nullptr;
+inline numpy_internals &get_numpy_internals() {
+    static numpy_internals *ptr = nullptr;
     if (!ptr)
         load_numpy_internals(ptr);
     return *ptr;
 }
 
-template <typename T> struct same_size {
-    template <typename U> using as = bool_constant<sizeof(T) == sizeof(U)>;
+template <typename T>
+struct same_size {
+    template <typename U>
+    using as = bool_constant<sizeof(T) == sizeof(U)>;
 };
 
-template <typename Concrete> constexpr int platform_lookup() { return -1; }
+template <typename Concrete>
+constexpr int platform_lookup() {
+    return -1;
+}
 
 // Lookup a type according to its size, and return a value corresponding to the NumPy typenum.
 template <typename Concrete, typename T, typename... Ts, typename... Ints>
@@ -132,15 +140,26 @@ struct npy_api {
         NPY_ARRAY_ALIGNED_ = 0x0100,
         NPY_ARRAY_WRITEABLE_ = 0x0400,
         NPY_BOOL_ = 0,
-        NPY_BYTE_, NPY_UBYTE_,
-        NPY_SHORT_, NPY_USHORT_,
-        NPY_INT_, NPY_UINT_,
-        NPY_LONG_, NPY_ULONG_,
-        NPY_LONGLONG_, NPY_ULONGLONG_,
-        NPY_FLOAT_, NPY_DOUBLE_, NPY_LONGDOUBLE_,
-        NPY_CFLOAT_, NPY_CDOUBLE_, NPY_CLONGDOUBLE_,
+        NPY_BYTE_,
+        NPY_UBYTE_,
+        NPY_SHORT_,
+        NPY_USHORT_,
+        NPY_INT_,
+        NPY_UINT_,
+        NPY_LONG_,
+        NPY_ULONG_,
+        NPY_LONGLONG_,
+        NPY_ULONGLONG_,
+        NPY_FLOAT_,
+        NPY_DOUBLE_,
+        NPY_LONGDOUBLE_,
+        NPY_CFLOAT_,
+        NPY_CDOUBLE_,
+        NPY_CLONGDOUBLE_,
         NPY_OBJECT_ = 17,
-        NPY_STRING_, NPY_UNICODE_, NPY_VOID_,
+        NPY_STRING_,
+        NPY_UNICODE_,
+        NPY_VOID_,
         // Platform-dependent normalization
         NPY_INT8_ = NPY_BYTE_,
         NPY_UINT8_ = NPY_UBYTE_,
@@ -149,13 +168,14 @@ struct npy_api {
         // `npy_common.h` defines the integer aliases. In order, it checks:
         // NPY_BITSOF_LONG, NPY_BITSOF_LONGLONG, NPY_BITSOF_INT, NPY_BITSOF_SHORT, NPY_BITSOF_CHAR
         // and assigns the alias to the first matching size, so we should check in this order.
-        NPY_INT32_ = platform_lookup<std::int32_t, long, int, short>(
-            NPY_LONG_, NPY_INT_, NPY_SHORT_),
+        NPY_INT32_
+        = platform_lookup<std::int32_t, long, int, short>(NPY_LONG_, NPY_INT_, NPY_SHORT_),
         NPY_UINT32_ = platform_lookup<std::uint32_t, unsigned long, unsigned int, unsigned short>(
             NPY_ULONG_, NPY_UINT_, NPY_USHORT_),
-        NPY_INT64_ = platform_lookup<std::int64_t, long, long long, int>(
-            NPY_LONG_, NPY_LONGLONG_, NPY_INT_),
-        NPY_UINT64_ = platform_lookup<std::uint64_t, unsigned long, unsigned long long, unsigned int>(
+        NPY_INT64_
+        = platform_lookup<std::int64_t, long, long long, int>(NPY_LONG_, NPY_LONGLONG_, NPY_INT_),
+        NPY_UINT64_
+        = platform_lookup<std::uint64_t, unsigned long, unsigned long long, unsigned int>(
             NPY_ULONG_, NPY_ULONGLONG_, NPY_UINT_),
     };
 
@@ -164,7 +184,7 @@ struct npy_api {
         int len;
     };
 
-    static npy_api& get() {
+    static npy_api &get() {
         static npy_api api = lookup();
         return api;
     }
@@ -178,9 +198,14 @@ struct npy_api {
 
     unsigned int (*PyArray_GetNDArrayCFeatureVersion_)();
     PyObject *(*PyArray_DescrFromType_)(int);
-    PyObject *(*PyArray_NewFromDescr_)
-        (PyTypeObject *, PyObject *, int, Py_intptr_t const *,
-         Py_intptr_t const *, void *, int, PyObject *);
+    PyObject *(*PyArray_NewFromDescr_)(PyTypeObject *,
+                                       PyObject *,
+                                       int,
+                                       Py_intptr_t const *,
+                                       Py_intptr_t const *,
+                                       void *,
+                                       int,
+                                       PyObject *);
     // Unused. Not removed because that affects ABI of the class.
     PyObject *(*PyArray_DescrNewFromType_)(int);
     int (*PyArray_CopyInto_)(PyObject *, PyObject *);
@@ -189,17 +214,23 @@ struct npy_api {
     PyTypeObject *PyVoidArrType_Type_;
     PyTypeObject *PyArrayDescr_Type_;
     PyObject *(*PyArray_DescrFromScalar_)(PyObject *);
-    PyObject *(*PyArray_FromAny_) (PyObject *, PyObject *, int, int, int, PyObject *);
-    int (*PyArray_DescrConverter_) (PyObject *, PyObject **);
-    bool (*PyArray_EquivTypes_) (PyObject *, PyObject *);
-    int (*PyArray_GetArrayParamsFromObject_)(PyObject *, PyObject *, unsigned char, PyObject **, int *,
-                                             Py_intptr_t *, PyObject **, PyObject *);
+    PyObject *(*PyArray_FromAny_)(PyObject *, PyObject *, int, int, int, PyObject *);
+    int (*PyArray_DescrConverter_)(PyObject *, PyObject **);
+    bool (*PyArray_EquivTypes_)(PyObject *, PyObject *);
+    int (*PyArray_GetArrayParamsFromObject_)(PyObject *,
+                                             PyObject *,
+                                             unsigned char,
+                                             PyObject **,
+                                             int *,
+                                             Py_intptr_t *,
+                                             PyObject **,
+                                             PyObject *);
     PyObject *(*PyArray_Squeeze_)(PyObject *);
     // Unused. Not removed because that affects ABI of the class.
     int (*PyArray_SetBaseObject_)(PyObject *, PyObject *);
-    PyObject* (*PyArray_Resize_)(PyObject*, PyArray_Dims*, int, int);
-    PyObject* (*PyArray_Newshape_)(PyObject*, PyArray_Dims*, int);
-    PyObject* (*PyArray_View_)(PyObject*, PyObject*, PyObject*);
+    PyObject *(*PyArray_Resize_)(PyObject *, PyArray_Dims *, int, int);
+    PyObject *(*PyArray_Newshape_)(PyObject *, PyArray_Dims *, int);
+    PyObject *(*PyArray_View_)(PyObject *, PyObject *, PyObject *);
 
 private:
     enum functions {
@@ -261,85 +292,103 @@ struct npy_api {
     }
 };
 
-inline PyArray_Proxy* array_proxy(void* ptr) {
-    return reinterpret_cast<PyArray_Proxy*>(ptr);
-}
+inline PyArray_Proxy *array_proxy(void *ptr) { return reinterpret_cast<PyArray_Proxy *>(ptr); }
 
-inline const PyArray_Proxy* array_proxy(const void* ptr) {
-    return reinterpret_cast<const PyArray_Proxy*>(ptr);
+inline const PyArray_Proxy *array_proxy(const void *ptr) {
+    return reinterpret_cast<const PyArray_Proxy *>(ptr);
 }
 
-inline PyArrayDescr_Proxy* array_descriptor_proxy(PyObject* ptr) {
-   return reinterpret_cast<PyArrayDescr_Proxy*>(ptr);
+inline PyArrayDescr_Proxy *array_descriptor_proxy(PyObject *ptr) {
+    return reinterpret_cast<PyArrayDescr_Proxy *>(ptr);
 }
 
-inline const PyArrayDescr_Proxy* array_descriptor_proxy(const PyObject* ptr) {
-   return reinterpret_cast<const PyArrayDescr_Proxy*>(ptr);
+inline const PyArrayDescr_Proxy *array_descriptor_proxy(const PyObject *ptr) {
+    return reinterpret_cast<const PyArrayDescr_Proxy *>(ptr);
 }
 
-inline bool check_flags(const void* ptr, int flag) {
+inline bool check_flags(const void *ptr, int flag) {
     return (flag == (array_proxy(ptr)->flags & flag));
 }
 
-template <typename T> struct is_std_array : std::false_type { };
-template <typename T, size_t N> struct is_std_array<std::array<T, N>> : std::true_type { };
-template <typename T> struct is_complex : std::false_type { };
-template <typename T> struct is_complex<std::complex<T>> : std::true_type { };
+template <typename T>
+struct is_std_array : std::false_type {};
+template <typename T, size_t N>
+struct is_std_array<std::array<T, N>> : std::true_type {};
+template <typename T>
+struct is_complex : std::false_type {};
+template <typename T>
+struct is_complex<std::complex<T>> : std::true_type {};
 
-template <typename T> struct array_info_scalar {
+template <typename T>
+struct array_info_scalar {
     using type = T;
     static constexpr bool is_array = false;
     static constexpr bool is_empty = false;
     static constexpr auto extents = const_name("");
-    static void append_extents(list& /* shape */) { }
+    static void append_extents(list & /* shape */) {}
 };
 // Computes underlying type and a comma-separated list of extents for array
 // types (any mix of std::array and built-in arrays). An array of char is
 // treated as scalar because it gets special handling.
-template <typename T> struct array_info : array_info_scalar<T> { };
-template <typename T, size_t N> struct array_info<std::array<T, N>> {
+template <typename T>
+struct array_info : array_info_scalar<T> {};
+template <typename T, size_t N>
+struct array_info<std::array<T, N>> {
     using type = typename array_info<T>::type;
     static constexpr bool is_array = true;
     static constexpr bool is_empty = (N == 0) || array_info<T>::is_empty;
     static constexpr size_t extent = N;
 
     // appends the extents to shape
-    static void append_extents(list& shape) {
+    static void append_extents(list &shape) {
         shape.append(N);
         array_info<T>::append_extents(shape);
     }
 
     static constexpr auto extents = const_name<array_info<T>::is_array>(
-        concat(const_name<N>(), array_info<T>::extents), const_name<N>()
-    );
+        concat(const_name<N>(), array_info<T>::extents), const_name<N>());
 };
 // For numpy we have special handling for arrays of characters, so we don't include
 // the size in the array extents.
-template <size_t N> struct array_info<char[N]> : array_info_scalar<char[N]> { };
-template <size_t N> struct array_info<std::array<char, N>> : array_info_scalar<std::array<char, N>> { };
-template <typename T, size_t N> struct array_info<T[N]> : array_info<std::array<T, N>> { };
-template <typename T> using remove_all_extents_t = typename array_info<T>::type;
-
-template <typename T> using is_pod_struct = all_of<
-    std::is_standard_layout<T>,     // since we're accessing directly in memory we need a standard layout type
-#if defined(__GLIBCXX__) && (__GLIBCXX__ < 20150422 || __GLIBCXX__ == 20150426 || __GLIBCXX__ == 20150623 || __GLIBCXX__ == 20150626 || __GLIBCXX__ == 20160803)
-    // libstdc++ < 5 (including versions 4.8.5, 4.9.3 and 4.9.4 which were released after 5)
-    // don't implement is_trivially_copyable, so approximate it
-    std::is_trivially_destructible<T>,
-    satisfies_any_of<T, std::has_trivial_copy_constructor, std::has_trivial_copy_assign>,
+template <size_t N>
+struct array_info<char[N]> : array_info_scalar<char[N]> {};
+template <size_t N>
+struct array_info<std::array<char, N>> : array_info_scalar<std::array<char, N>> {};
+template <typename T, size_t N>
+struct array_info<T[N]> : array_info<std::array<T, N>> {};
+template <typename T>
+using remove_all_extents_t = typename array_info<T>::type;
+
+template <typename T>
+using is_pod_struct
+    = all_of<std::is_standard_layout<T>, // since we're accessing directly in memory we need a
+                                         // standard layout type
+#if defined(__GLIBCXX__)                                                                          \
+    && (__GLIBCXX__ < 20150422 || __GLIBCXX__ == 20150426 || __GLIBCXX__ == 20150623              \
+        || __GLIBCXX__ == 20150626 || __GLIBCXX__ == 20160803)
+             // libstdc++ < 5 (including versions 4.8.5, 4.9.3 and 4.9.4 which were released after
+             // 5) don't implement is_trivially_copyable, so approximate it
+             std::is_trivially_destructible<T>,
+             satisfies_any_of<T, std::has_trivial_copy_constructor, std::has_trivial_copy_assign>,
 #else
-    std::is_trivially_copyable<T>,
+             std::is_trivially_copyable<T>,
 #endif
-    satisfies_none_of<T, std::is_reference, std::is_array, is_std_array, std::is_arithmetic, is_complex, std::is_enum>
->;
+             satisfies_none_of<T,
+                               std::is_reference,
+                               std::is_array,
+                               is_std_array,
+                               std::is_arithmetic,
+                               is_complex,
+                               std::is_enum>>;
 
 // Replacement for std::is_pod (deprecated in C++20)
-template <typename T> using is_pod = all_of<
-    std::is_standard_layout<T>,
-    std::is_trivial<T>
->;
+template <typename T>
+using is_pod = all_of<std::is_standard_layout<T>, std::is_trivial<T>>;
 
-template <ssize_t Dim = 0, typename Strides> ssize_t byte_offset_unsafe(const Strides &) { return 0; }
+template <ssize_t Dim = 0, typename Strides>
+ssize_t byte_offset_unsafe(const Strides &) {
+    return 0;
+}
 template <ssize_t Dim = 0, typename Strides, typename... Ix>
 ssize_t byte_offset_unsafe(const Strides &strides, ssize_t i, Ix... index) {
     return i * strides[Dim] + byte_offset_unsafe<Dim + 1>(strides, index...);
@@ -347,7 +396,7 @@ ssize_t byte_offset_unsafe(const Strides &strides, ssize_t i, Ix... index) {
 
 /**
  * Proxy class providing unsafe, unchecked const access to array data.  This is constructed through
- * the `unchecked<T, N>()` method of `array` or the `unchecked<N>()` method of `array_t<T>`.  `Dims`
+ * the `unchecked<T, N>()` method of `array` or the `unchecked<N>()` method of `array_t<T>`. `Dims`
  * will be -1 for dimensions determined at runtime.
  */
 template <typename T, ssize_t Dims>
@@ -357,15 +406,17 @@ class unchecked_reference {
     const unsigned char *data_;
     // Storing the shape & strides in local variables (i.e. these arrays) allows the compiler to
     // make large performance gains on big, nested loops, but requires compile-time dimensions
-    conditional_t<Dynamic, const ssize_t *, std::array<ssize_t, (size_t) Dims>>
-            shape_, strides_;
+    conditional_t<Dynamic, const ssize_t *, std::array<ssize_t, (size_t) Dims>> shape_, strides_;
     const ssize_t dims_;
 
     friend class pybind11::array;
     // Constructor for compile-time dimensions:
     template <bool Dyn = Dynamic>
-    unchecked_reference(const void *data, const ssize_t *shape, const ssize_t *strides, enable_if_t<!Dyn, ssize_t>)
-    : data_{reinterpret_cast<const unsigned char *>(data)}, dims_{Dims} {
+    unchecked_reference(const void *data,
+                        const ssize_t *shape,
+                        const ssize_t *strides,
+                        enable_if_t<!Dyn, ssize_t>)
+        : data_{reinterpret_cast<const unsigned char *>(data)}, dims_{Dims} {
         for (size_t i = 0; i < (size_t) dims_; i++) {
             shape_[i] = shape[i];
             strides_[i] = strides[i];
@@ -373,8 +424,12 @@ class unchecked_reference {
     }
     // Constructor for runtime dimensions:
     template <bool Dyn = Dynamic>
-    unchecked_reference(const void *data, const ssize_t *shape, const ssize_t *strides, enable_if_t<Dyn, ssize_t> dims)
-    : data_{reinterpret_cast<const unsigned char *>(data)}, shape_{shape}, strides_{strides}, dims_{dims} {}
+    unchecked_reference(const void *data,
+                        const ssize_t *shape,
+                        const ssize_t *strides,
+                        enable_if_t<Dyn, ssize_t> dims)
+        : data_{reinterpret_cast<const unsigned char *>(data)}, shape_{shape}, strides_{strides},
+          dims_{dims} {}
 
 public:
     /**
@@ -382,20 +437,27 @@ class unchecked_reference {
      * number of dimensions, this requires the correct number of arguments; for run-time
      * dimensionality, this is not checked (and so is up to the caller to use safely).
      */
-    template <typename... Ix> const T &operator()(Ix... index) const {
+    template <typename... Ix>
+    const T &operator()(Ix... index) const {
         static_assert(ssize_t{sizeof...(Ix)} == Dims || Dynamic,
-                "Invalid number of indices for unchecked array reference");
-        return *reinterpret_cast<const T *>(data_ + byte_offset_unsafe(strides_, ssize_t(index)...));
+                      "Invalid number of indices for unchecked array reference");
+        return *reinterpret_cast<const T *>(data_
+                                            + byte_offset_unsafe(strides_, ssize_t(index)...));
     }
     /**
      * Unchecked const reference access to data; this operator only participates if the reference
      * is to a 1-dimensional array.  When present, this is exactly equivalent to `obj(index)`.
      */
     template <ssize_t D = Dims, typename = enable_if_t<D == 1 || Dynamic>>
-    const T &operator[](ssize_t index) const { return operator()(index); }
+    const T &operator[](ssize_t index) const {
+        return operator()(index);
+    }
 
     /// Pointer access to the data at the given indices.
-    template <typename... Ix> const T *data(Ix... ix) const { return &operator()(ssize_t(ix)...); }
+    template <typename... Ix>
+    const T *data(Ix... ix) const {
+        return &operator()(ssize_t(ix)...);
+    }
 
     /// Returns the item size, i.e. sizeof(T)
     constexpr static ssize_t itemsize() { return sizeof(T); }
@@ -406,21 +468,22 @@ class unchecked_reference {
     /// Returns the number of dimensions of the array
     ssize_t ndim() const { return dims_; }
 
-    /// Returns the total number of elements in the referenced array, i.e. the product of the shapes
+    /// Returns the total number of elements in the referenced array, i.e. the product of the
+    /// shapes
     template <bool Dyn = Dynamic>
     enable_if_t<!Dyn, ssize_t> size() const {
-        return std::accumulate(shape_.begin(), shape_.end(), (ssize_t) 1, std::multiplies<ssize_t>());
+        return std::accumulate(
+            shape_.begin(), shape_.end(), (ssize_t) 1, std::multiplies<ssize_t>());
     }
     template <bool Dyn = Dynamic>
     enable_if_t<Dyn, ssize_t> size() const {
         return std::accumulate(shape_, shape_ + ndim(), (ssize_t) 1, std::multiplies<ssize_t>());
     }
 
-    /// Returns the total number of bytes used by the referenced data.  Note that the actual span in
-    /// memory may be larger if the referenced array has non-contiguous strides (e.g. for a slice).
-    ssize_t nbytes() const {
-        return size() * itemsize();
-    }
+    /// Returns the total number of bytes used by the referenced data.  Note that the actual span
+    /// in memory may be larger if the referenced array has non-contiguous strides (e.g. for a
+    /// slice).
+    ssize_t nbytes() const { return size() * itemsize(); }
 };
 
 template <typename T, ssize_t Dims>
@@ -429,15 +492,17 @@ class unchecked_mutable_reference : public unchecked_reference<T, Dims> {
     using ConstBase = unchecked_reference<T, Dims>;
     using ConstBase::ConstBase;
     using ConstBase::Dynamic;
+
 public:
     // Bring in const-qualified versions from base class
     using ConstBase::operator();
     using ConstBase::operator[];
 
     /// Mutable, unchecked access to data at the given indices.
-    template <typename... Ix> T& operator()(Ix... index) {
+    template <typename... Ix>
+    T &operator()(Ix... index) {
         static_assert(ssize_t{sizeof...(Ix)} == Dims || Dynamic,
-                "Invalid number of indices for unchecked array reference");
+                      "Invalid number of indices for unchecked array reference");
         return const_cast<T &>(ConstBase::operator()(index...));
     }
     /**
@@ -446,18 +511,25 @@ class unchecked_mutable_reference : public unchecked_reference<T, Dims> {
      * exactly equivalent to `obj(index)`.
      */
     template <ssize_t D = Dims, typename = enable_if_t<D == 1 || Dynamic>>
-    T &operator[](ssize_t index) { return operator()(index); }
+    T &operator[](ssize_t index) {
+        return operator()(index);
+    }
 
     /// Mutable pointer access to the data at the given indices.
-    template <typename... Ix> T *mutable_data(Ix... ix) { return &operator()(ssize_t(ix)...); }
+    template <typename... Ix>
+    T *mutable_data(Ix... ix) {
+        return &operator()(ssize_t(ix)...);
+    }
 };
 
 template <typename T, ssize_t Dim>
 struct type_caster<unchecked_reference<T, Dim>> {
-    static_assert(Dim == 0 && Dim > 0 /* always fail */, "unchecked array proxy object is not castable");
+    static_assert(Dim == 0 && Dim > 0 /* always fail */,
+                  "unchecked array proxy object is not castable");
 };
 template <typename T, ssize_t Dim>
-struct type_caster<unchecked_mutable_reference<T, Dim>> : type_caster<unchecked_reference<T, Dim>> {};
+struct type_caster<unchecked_mutable_reference<T, Dim>>
+    : type_caster<unchecked_reference<T, Dim>> {};
 
 PYBIND11_NAMESPACE_END(detail)
 
@@ -497,25 +569,20 @@ class dtype : public object {
     }
 
     /// Return dtype associated with a C++ type.
-    template <typename T> static dtype of() {
+    template <typename T>
+    static dtype of() {
         return detail::npy_format_descriptor<typename std::remove_cv<T>::type>::dtype();
     }
 
     /// Size of the data type in bytes.
-    ssize_t itemsize() const {
-        return detail::array_descriptor_proxy(m_ptr)->elsize;
-    }
+    ssize_t itemsize() const { return detail::array_descriptor_proxy(m_ptr)->elsize; }
 
     /// Returns true for structured data types.
-    bool has_fields() const {
-        return detail::array_descriptor_proxy(m_ptr)->names != nullptr;
-    }
+    bool has_fields() const { return detail::array_descriptor_proxy(m_ptr)->names != nullptr; }
 
     /// Single-character code for dtype's kind.
     /// For example, floating point types are 'f' and integral types are 'i'.
-    char kind() const {
-        return detail::array_descriptor_proxy(m_ptr)->kind;
-    }
+    char kind() const { return detail::array_descriptor_proxy(m_ptr)->kind; }
 
     /// Single-character for dtype's type.
     /// For example, ``float`` is 'f', ``double`` 'd', ``int`` 'i', and ``long`` 'l'.
@@ -529,7 +596,10 @@ class dtype : public object {
 private:
     static object _dtype_from_pep3118() {
         static PyObject *obj = module_::import("numpy.core._internal")
-            .attr("_dtype_from_pep3118").cast<object>().release().ptr();
+                                   .attr("_dtype_from_pep3118")
+                                   .cast<object>()
+                                   .release()
+                                   .ptr();
         return reinterpret_borrow<object>(obj);
     }
 
@@ -539,7 +609,11 @@ class dtype : public object {
         if (!has_fields())
             return *this;
 
-        struct field_descr { PYBIND11_STR_TYPE name; object format; pybind11::int_ offset; };
+        struct field_descr {
+            PYBIND11_STR_TYPE name;
+            object format;
+            pybind11::int_ offset;
+        };
         std::vector<field_descr> field_descriptors;
 
         for (auto field : attr("fields").attr("items")()) {
@@ -549,16 +623,18 @@ class dtype : public object {
             auto offset = spec[1].cast<tuple>()[1].cast<pybind11::int_>();
             if ((len(name) == 0u) && format.kind() == 'V')
                 continue;
-            field_descriptors.push_back({(PYBIND11_STR_TYPE) name, format.strip_padding(format.itemsize()), offset});
+            field_descriptors.push_back(
+                {(PYBIND11_STR_TYPE) name, format.strip_padding(format.itemsize()), offset});
         }
 
-        std::sort(field_descriptors.begin(), field_descriptors.end(),
-                  [](const field_descr& a, const field_descr& b) {
+        std::sort(field_descriptors.begin(),
+                  field_descriptors.end(),
+                  [](const field_descr &a, const field_descr &b) {
                       return a.offset.cast<int>() < b.offset.cast<int>();
                   });
 
         list names, formats, offsets;
-        for (auto& descr : field_descriptors) {
+        for (auto &descr : field_descriptors) {
             names.append(descr.name);
             formats.append(descr.format);
             offsets.append(descr.offset);
@@ -583,8 +659,11 @@ class array : public buffer {
     using StridesContainer = detail::any_container<ssize_t>;
 
     // Constructs an array taking shape/strides from arbitrary container types
-    array(const pybind11::dtype &dt, ShapeContainer shape, StridesContainer strides,
-          const void *ptr = nullptr, handle base = handle()) {
+    array(const pybind11::dtype &dt,
+          ShapeContainer shape,
+          StridesContainer strides,
+          const void *ptr = nullptr,
+          handle base = handle()) {
 
         if (strides->empty())
             *strides = detail::c_strides(*shape, dt.itemsize());
@@ -598,7 +677,8 @@ class array : public buffer {
         if (base && ptr) {
             if (isinstance<array>(base))
                 /* Copy flags from base (except ownership bit) */
-                flags = reinterpret_borrow<array>(base).flags() & ~detail::npy_api::NPY_ARRAY_OWNDATA_;
+                flags = reinterpret_borrow<array>(base).flags()
+                        & ~detail::npy_api::NPY_ARRAY_OWNDATA_;
             else
                 /* Writable by default, easy to downgrade later on if needed */
                 flags = detail::npy_api::NPY_ARRAY_WRITEABLE_;
@@ -606,43 +686,54 @@ class array : public buffer {
 
         auto &api = detail::npy_api::get();
         auto tmp = reinterpret_steal<object>(api.PyArray_NewFromDescr_(
-            api.PyArray_Type_, descr.release().ptr(), (int) ndim,
+            api.PyArray_Type_,
+            descr.release().ptr(),
+            (int) ndim,
             // Use reinterpret_cast for PyPy on Windows (remove if fixed, checked on 7.3.1)
-            reinterpret_cast<Py_intptr_t*>(shape->data()),
-            reinterpret_cast<Py_intptr_t*>(strides->data()),
-            const_cast<void *>(ptr), flags, nullptr));
+            reinterpret_cast<Py_intptr_t *>(shape->data()),
+            reinterpret_cast<Py_intptr_t *>(strides->data()),
+            const_cast<void *>(ptr),
+            flags,
+            nullptr));
         if (!tmp)
             throw error_already_set();
         if (ptr) {
             if (base) {
                 api.PyArray_SetBaseObject_(tmp.ptr(), base.inc_ref().ptr());
             } else {
-                tmp = reinterpret_steal<object>(api.PyArray_NewCopy_(tmp.ptr(), -1 /* any order */));
+                tmp = reinterpret_steal<object>(
+                    api.PyArray_NewCopy_(tmp.ptr(), -1 /* any order */));
             }
         }
         m_ptr = tmp.release().ptr();
     }
 
-    array(const pybind11::dtype &dt, ShapeContainer shape, const void *ptr = nullptr, handle base = handle())
-        : array(dt, std::move(shape), {}, ptr, base) { }
+    array(const pybind11::dtype &dt,
+          ShapeContainer shape,
+          const void *ptr = nullptr,
+          handle base = handle())
+        : array(dt, std::move(shape), {}, ptr, base) {}
 
-    template <typename T, typename = detail::enable_if_t<std::is_integral<T>::value && !std::is_same<bool, T>::value>>
+    template <typename T,
+              typename
+              = detail::enable_if_t<std::is_integral<T>::value && !std::is_same<bool, T>::value>>
     array(const pybind11::dtype &dt, T count, const void *ptr = nullptr, handle base = handle())
-        : array(dt, {{count}}, ptr, base) { }
+        : array(dt, {{count}}, ptr, base) {}
 
     template <typename T>
     array(ShapeContainer shape, StridesContainer strides, const T *ptr, handle base = handle())
-        : array(pybind11::dtype::of<T>(), std::move(shape), std::move(strides), ptr, base) { }
+        : array(pybind11::dtype::of<T>(), std::move(shape), std::move(strides), ptr, base) {}
 
     template <typename T>
     array(ShapeContainer shape, const T *ptr, handle base = handle())
-        : array(std::move(shape), {}, ptr, base) { }
+        : array(std::move(shape), {}, ptr, base) {}
 
     template <typename T>
-    explicit array(ssize_t count, const T *ptr, handle base = handle()) : array({count}, {}, ptr, base) { }
+    explicit array(ssize_t count, const T *ptr, handle base = handle())
+        : array({count}, {}, ptr, base) {}
 
     explicit array(const buffer_info &info, handle base = handle())
-    : array(pybind11::dtype(info), info.shape, info.strides, info.ptr, base) { }
+        : array(pybind11::dtype(info), info.shape, info.strides, info.ptr, base) {}
 
     /// Array descriptor (dtype)
     pybind11::dtype dtype() const {
@@ -660,24 +751,16 @@ class array : public buffer {
     }
 
     /// Total number of bytes
-    ssize_t nbytes() const {
-        return size() * itemsize();
-    }
+    ssize_t nbytes() const { return size() * itemsize(); }
 
     /// Number of dimensions
-    ssize_t ndim() const {
-        return detail::array_proxy(m_ptr)->nd;
-    }
+    ssize_t ndim() const { return detail::array_proxy(m_ptr)->nd; }
 
     /// Base object
-    object base() const {
-        return reinterpret_borrow<object>(detail::array_proxy(m_ptr)->base);
-    }
+    object base() const { return reinterpret_borrow<object>(detail::array_proxy(m_ptr)->base); }
 
     /// Dimensions of the array
-    const ssize_t* shape() const {
-        return detail::array_proxy(m_ptr)->dimensions;
-    }
+    const ssize_t *shape() const { return detail::array_proxy(m_ptr)->dimensions; }
 
     /// Dimension along a given axis
     ssize_t shape(ssize_t dim) const {
@@ -687,9 +770,7 @@ class array : public buffer {
     }
 
     /// Strides of the array
-    const ssize_t* strides() const {
-        return detail::array_proxy(m_ptr)->strides;
-    }
+    const ssize_t *strides() const { return detail::array_proxy(m_ptr)->strides; }
 
     /// Stride along a given axis
     ssize_t strides(ssize_t dim) const {
@@ -699,9 +780,7 @@ class array : public buffer {
     }
 
     /// Return the NumPy array flags
-    int flags() const {
-        return detail::array_proxy(m_ptr)->flags;
-    }
+    int flags() const { return detail::array_proxy(m_ptr)->flags; }
 
     /// If set, the array is writeable (otherwise the buffer is read-only)
     bool writeable() const {
@@ -715,21 +794,24 @@ class array : public buffer {
 
     /// Pointer to the contained data. If index is not provided, points to the
     /// beginning of the buffer. May throw if the index would lead to out of bounds access.
-    template<typename... Ix> const void* data(Ix... index) const {
+    template <typename... Ix>
+    const void *data(Ix... index) const {
         return static_cast<const void *>(detail::array_proxy(m_ptr)->data + offset_at(index...));
     }
 
     /// Mutable pointer to the contained data. If index is not provided, points to the
     /// beginning of the buffer. May throw if the index would lead to out of bounds access.
     /// May throw if the array is not writeable.
-    template<typename... Ix> void* mutable_data(Ix... index) {
+    template <typename... Ix>
+    void *mutable_data(Ix... index) {
         check_writeable();
         return static_cast<void *>(detail::array_proxy(m_ptr)->data + offset_at(index...));
     }
 
     /// Byte offset from beginning of the array to a given index (full or partial).
     /// May throw if the index would lead to out of bounds access.
-    template<typename... Ix> ssize_t offset_at(Ix... index) const {
+    template <typename... Ix>
+    ssize_t offset_at(Ix... index) const {
         if ((ssize_t) sizeof...(index) > ndim())
             fail_dim_check(sizeof...(index), "too many indices for an array");
         return byte_offset(ssize_t(index)...);
@@ -739,7 +821,8 @@ class array : public buffer {
 
     /// Item count from beginning of the array to a given index (full or partial).
     /// May throw if the index would lead to out of bounds access.
-    template<typename... Ix> ssize_t index_at(Ix... index) const {
+    template <typename... Ix>
+    ssize_t index_at(Ix... index) const {
         return offset_at(index...) / itemsize();
     }
 
@@ -749,30 +832,35 @@ class array : public buffer {
      * care: the array must not be destroyed or reshaped for the duration of the returned object,
      * and the caller must take care not to access invalid dimensions or dimension indices.
      */
-    template <typename T, ssize_t Dims = -1> detail::unchecked_mutable_reference<T, Dims> mutable_unchecked() & {
+    template <typename T, ssize_t Dims = -1>
+    detail::unchecked_mutable_reference<T, Dims> mutable_unchecked() & {
         if (PYBIND11_SILENCE_MSVC_C4127(Dims >= 0) && ndim() != Dims)
-            throw std::domain_error("array has incorrect number of dimensions: " + std::to_string(ndim()) +
-                    "; expected " + std::to_string(Dims));
-        return detail::unchecked_mutable_reference<T, Dims>(mutable_data(), shape(), strides(), ndim());
+            throw std::domain_error("array has incorrect number of dimensions: "
+                                    + std::to_string(ndim()) + "; expected "
+                                    + std::to_string(Dims));
+        return detail::unchecked_mutable_reference<T, Dims>(
+            mutable_data(), shape(), strides(), ndim());
     }
 
     /**
      * Returns a proxy object that provides const access to the array's data without bounds or
      * dimensionality checking.  Unlike `mutable_unchecked()`, this does not require that the
-     * underlying array have the `writable` flag.  Use with care: the array must not be destroyed or
-     * reshaped for the duration of the returned object, and the caller must take care not to access
-     * invalid dimensions or dimension indices.
+     * underlying array have the `writable` flag.  Use with care: the array must not be destroyed
+     * or reshaped for the duration of the returned object, and the caller must take care not to
+     * access invalid dimensions or dimension indices.
      */
-    template <typename T, ssize_t Dims = -1> detail::unchecked_reference<T, Dims> unchecked() const & {
+    template <typename T, ssize_t Dims = -1>
+    detail::unchecked_reference<T, Dims> unchecked() const & {
         if (PYBIND11_SILENCE_MSVC_C4127(Dims >= 0) && ndim() != Dims)
-            throw std::domain_error("array has incorrect number of dimensions: " + std::to_string(ndim()) +
-                    "; expected " + std::to_string(Dims));
+            throw std::domain_error("array has incorrect number of dimensions: "
+                                    + std::to_string(ndim()) + "; expected "
+                                    + std::to_string(Dims));
         return detail::unchecked_reference<T, Dims>(data(), shape(), strides(), ndim());
     }
 
     /// Return a new view with all of the dimensions of length 1 removed
     array squeeze() {
-        auto& api = detail::npy_api::get();
+        auto &api = detail::npy_api::get();
         return reinterpret_steal<array>(api.PyArray_Squeeze_(m_ptr));
     }
 
@@ -780,17 +868,18 @@ class array : public buffer {
     /// If refcheck is true and more that one reference exist to this array
     /// then resize will succeed only if it makes a reshape, i.e. original size doesn't change
     void resize(ShapeContainer new_shape, bool refcheck = true) {
-        detail::npy_api::PyArray_Dims d = {
-            // Use reinterpret_cast for PyPy on Windows (remove if fixed, checked on 7.3.1)
-            reinterpret_cast<Py_intptr_t*>(new_shape->data()),
-            int(new_shape->size())
-        };
+        detail::npy_api::PyArray_Dims d
+            = {// Use reinterpret_cast for PyPy on Windows (remove if fixed, checked on 7.3.1)
+               reinterpret_cast<Py_intptr_t *>(new_shape->data()),
+               int(new_shape->size())};
         // try to resize, set ordering param to -1 cause it's not used anyway
         auto new_array = reinterpret_steal<object>(
-            detail::npy_api::get().PyArray_Resize_(m_ptr, &d, int(refcheck), -1)
-        );
-        if (!new_array) throw error_already_set();
-        if (isinstance<array>(new_array)) { *this = std::move(new_array); }
+            detail::npy_api::get().PyArray_Resize_(m_ptr, &d, int(refcheck), -1));
+        if (!new_array)
+            throw error_already_set();
+        if (isinstance<array>(new_array)) {
+            *this = std::move(new_array);
+        }
     }
 
     /// Optional `order` parameter omitted, to be added as needed.
@@ -830,14 +919,16 @@ class array : public buffer {
     }
 
 protected:
-    template<typename, typename> friend struct detail::npy_format_descriptor;
+    template <typename, typename>
+    friend struct detail::npy_format_descriptor;
 
-    void fail_dim_check(ssize_t dim, const std::string& msg) const {
-        throw index_error(msg + ": " + std::to_string(dim) +
-                          " (ndim = " + std::to_string(ndim()) + ")");
+    void fail_dim_check(ssize_t dim, const std::string &msg) const {
+        throw index_error(msg + ": " + std::to_string(dim) + " (ndim = " + std::to_string(ndim())
+                          + ")");
     }
 
-    template<typename... Ix> ssize_t byte_offset(Ix... index) const {
+    template <typename... Ix>
+    ssize_t byte_offset(Ix... index) const {
         check_dimensions(index...);
         return detail::byte_offset_unsafe(strides(), ssize_t(index)...);
     }
@@ -847,17 +938,19 @@ class array : public buffer {
             throw std::domain_error("array is not writeable");
     }
 
-    template<typename... Ix> void check_dimensions(Ix... index) const {
+    template <typename... Ix>
+    void check_dimensions(Ix... index) const {
         check_dimensions_impl(ssize_t(0), shape(), ssize_t(index)...);
     }
 
-    void check_dimensions_impl(ssize_t, const ssize_t*) const { }
+    void check_dimensions_impl(ssize_t, const ssize_t *) const {}
 
-    template<typename... Ix> void check_dimensions_impl(ssize_t axis, const ssize_t* shape, ssize_t i, Ix... index) const {
+    template <typename... Ix>
+    void check_dimensions_impl(ssize_t axis, const ssize_t *shape, ssize_t i, Ix... index) const {
         if (i >= *shape) {
-            throw index_error(std::string("index ") + std::to_string(i) +
-                              " is out of bounds for axis " + std::to_string(axis) +
-                              " with size " + std::to_string(*shape));
+            throw index_error(std::string("index ") + std::to_string(i)
+                              + " is out of bounds for axis " + std::to_string(axis)
+                              + " with size " + std::to_string(*shape));
         }
         check_dimensions_impl(axis + 1, shape + 1, index...);
     }
@@ -873,36 +966,48 @@ class array : public buffer {
     }
 };
 
-template <typename T, int ExtraFlags = array::forcecast> class array_t : public array {
+template <typename T, int ExtraFlags = array::forcecast>
+class array_t : public array {
 private:
     struct private_ctor {};
     // Delegating constructor needed when both moving and accessing in the same constructor
-    array_t(private_ctor, ShapeContainer &&shape, StridesContainer &&strides, const T *ptr, handle base)
+    array_t(private_ctor,
+            ShapeContainer &&shape,
+            StridesContainer &&strides,
+            const T *ptr,
+            handle base)
         : array(std::move(shape), std::move(strides), ptr, base) {}
+
 public:
     static_assert(!detail::array_info<T>::is_array, "Array types cannot be used with array_t");
 
     using value_type = T;
 
     array_t() : array(0, static_cast<const T *>(nullptr)) {}
-    array_t(handle h, borrowed_t) : array(h, borrowed_t{}) { }
-    array_t(handle h, stolen_t) : array(h, stolen_t{}) { }
+    array_t(handle h, borrowed_t) : array(h, borrowed_t{}) {}
+    array_t(handle h, stolen_t) : array(h, stolen_t{}) {}
 
     PYBIND11_DEPRECATED("Use array_t<T>::ensure() instead")
     array_t(handle h, bool is_borrowed) : array(raw_array_t(h.ptr()), stolen_t{}) {
-        if (!m_ptr) PyErr_Clear();
-        if (!is_borrowed) Py_XDECREF(h.ptr());
+        if (!m_ptr)
+            PyErr_Clear();
+        if (!is_borrowed)
+            Py_XDECREF(h.ptr());
     }
 
     // NOLINTNEXTLINE(google-explicit-constructor)
     array_t(const object &o) : array(raw_array_t(o.ptr()), stolen_t{}) {
-        if (!m_ptr) throw error_already_set();
+        if (!m_ptr)
+            throw error_already_set();
     }
 
-    explicit array_t(const buffer_info& info, handle base = handle()) : array(info, base) { }
+    explicit array_t(const buffer_info &info, handle base = handle()) : array(info, base) {}
 
-    array_t(ShapeContainer shape, StridesContainer strides, const T *ptr = nullptr, handle base = handle())
-        : array(std::move(shape), std::move(strides), ptr, base) { }
+    array_t(ShapeContainer shape,
+            StridesContainer strides,
+            const T *ptr = nullptr,
+            handle base = handle())
+        : array(std::move(shape), std::move(strides), ptr, base) {}
 
     explicit array_t(ShapeContainer shape, const T *ptr = nullptr, handle base = handle())
         : array_t(private_ctor{},
@@ -913,36 +1018,41 @@ template <typename T, int ExtraFlags = array::forcecast> class array_t : public
                   base) {}
 
     explicit array_t(ssize_t count, const T *ptr = nullptr, handle base = handle())
-        : array({count}, {}, ptr, base) { }
+        : array({count}, {}, ptr, base) {}
 
-    constexpr ssize_t itemsize() const {
-        return sizeof(T);
-    }
+    constexpr ssize_t itemsize() const { return sizeof(T); }
 
-    template<typename... Ix> ssize_t index_at(Ix... index) const {
+    template <typename... Ix>
+    ssize_t index_at(Ix... index) const {
         return offset_at(index...) / itemsize();
     }
 
-    template<typename... Ix> const T* data(Ix... index) const {
-        return static_cast<const T*>(array::data(index...));
+    template <typename... Ix>
+    const T *data(Ix... index) const {
+        return static_cast<const T *>(array::data(index...));
     }
 
-    template<typename... Ix> T* mutable_data(Ix... index) {
-        return static_cast<T*>(array::mutable_data(index...));
+    template <typename... Ix>
+    T *mutable_data(Ix... index) {
+        return static_cast<T *>(array::mutable_data(index...));
     }
 
     // Reference to element at a given index
-    template<typename... Ix> const T& at(Ix... index) const {
+    template <typename... Ix>
+    const T &at(Ix... index) const {
         if ((ssize_t) sizeof...(index) != ndim())
             fail_dim_check(sizeof...(index), "index dimension mismatch");
-        return *(static_cast<const T*>(array::data()) + byte_offset(ssize_t(index)...) / itemsize());
+        return *(static_cast<const T *>(array::data())
+                 + byte_offset(ssize_t(index)...) / itemsize());
     }
 
     // Mutable reference to element at a given index
-    template<typename... Ix> T& mutable_at(Ix... index) {
+    template <typename... Ix>
+    T &mutable_at(Ix... index) {
         if ((ssize_t) sizeof...(index) != ndim())
             fail_dim_check(sizeof...(index), "index dimension mismatch");
-        return *(static_cast<T*>(array::mutable_data()) + byte_offset(ssize_t(index)...) / itemsize());
+        return *(static_cast<T *>(array::mutable_data())
+                 + byte_offset(ssize_t(index)...) / itemsize());
     }
 
     /**
@@ -951,7 +1061,8 @@ template <typename T, int ExtraFlags = array::forcecast> class array_t : public
      * care: the array must not be destroyed or reshaped for the duration of the returned object,
      * and the caller must take care not to access invalid dimensions or dimension indices.
      */
-    template <ssize_t Dims = -1> detail::unchecked_mutable_reference<T, Dims> mutable_unchecked() & {
+    template <ssize_t Dims = -1>
+    detail::unchecked_mutable_reference<T, Dims> mutable_unchecked() & {
         return array::mutable_unchecked<T, Dims>();
     }
 
@@ -962,7 +1073,8 @@ template <typename T, int ExtraFlags = array::forcecast> class array_t : public
      * for the duration of the returned object, and the caller must take care not to access invalid
      * dimensions or dimension indices.
      */
-    template <ssize_t Dims = -1> detail::unchecked_reference<T, Dims> unchecked() const & {
+    template <ssize_t Dims = -1>
+    detail::unchecked_reference<T, Dims> unchecked() const & {
         return array::unchecked<T, Dims>();
     }
 
@@ -978,7 +1090,8 @@ template <typename T, int ExtraFlags = array::forcecast> class array_t : public
     static bool check_(handle h) {
         const auto &api = detail::npy_api::get();
         return api.PyArray_Check_(h.ptr())
-               && api.PyArray_EquivTypes_(detail::array_proxy(h.ptr())->descr, dtype::of<T>().ptr())
+               && api.PyArray_EquivTypes_(detail::array_proxy(h.ptr())->descr,
+                                          dtype::of<T>().ptr())
                && detail::check_flags(h.ptr(), ExtraFlags & (array::c_style | array::f_style));
     }
 
@@ -989,9 +1102,13 @@ template <typename T, int ExtraFlags = array::forcecast> class array_t : public
             PyErr_SetString(PyExc_ValueError, "cannot create a pybind11::array_t from a nullptr");
             return nullptr;
         }
-        return detail::npy_api::get().PyArray_FromAny_(
-            ptr, dtype::of<T>().release().ptr(), 0, 0,
-            detail::npy_api::NPY_ARRAY_ENSUREARRAY_ | ExtraFlags, nullptr);
+        return detail::npy_api::get().PyArray_FromAny_(ptr,
+                                                       dtype::of<T>().release().ptr(),
+                                                       0,
+                                                       0,
+                                                       detail::npy_api::NPY_ARRAY_ENSUREARRAY_
+                                                           | ExtraFlags,
+                                                       nullptr);
     }
 };
 
@@ -1002,10 +1119,12 @@ struct format_descriptor<T, detail::enable_if_t<detail::is_pod_struct<T>::value>
     }
 };
 
-template <size_t N> struct format_descriptor<char[N]> {
+template <size_t N>
+struct format_descriptor<char[N]> {
     static std::string format() { return std::to_string(N) + "s"; }
 };
-template <size_t N> struct format_descriptor<std::array<char, N>> {
+template <size_t N>
+struct format_descriptor<std::array<char, N>> {
     static std::string format() { return std::to_string(N) + "s"; }
 };
 
@@ -1046,7 +1165,7 @@ struct pyobject_caster<array_t<T, ExtraFlags>> {
 
 template <typename T>
 struct compare_buffer_info<T, detail::enable_if_t<detail::is_pod_struct<T>::value>> {
-    static bool compare(const buffer_info& b) {
+    static bool compare(const buffer_info &b) {
         return npy_api::get().PyArray_EquivTypes_(dtype::of<T>().ptr(), dtype(b).ptr());
     }
 };
@@ -1057,67 +1176,90 @@ struct npy_format_descriptor_name;
 template <typename T>
 struct npy_format_descriptor_name<T, enable_if_t<std::is_integral<T>::value>> {
     static constexpr auto name = const_name<std::is_same<T, bool>::value>(
-        const_name("bool"), const_name<std::is_signed<T>::value>("numpy.int", "numpy.uint") + const_name<sizeof(T)*8>()
-    );
+        const_name("bool"),
+        const_name<std::is_signed<T>::value>("numpy.int", "numpy.uint")
+            + const_name<sizeof(T) * 8>());
 };
 
 template <typename T>
 struct npy_format_descriptor_name<T, enable_if_t<std::is_floating_point<T>::value>> {
-    static constexpr auto name = const_name<std::is_same<T, float>::value
-                                   || std::is_same<T, const float>::value
-                                   || std::is_same<T, double>::value
-                                   || std::is_same<T, const double>::value>(
-        const_name("numpy.float") + const_name<sizeof(T)*8>(), const_name("numpy.longdouble")
-    );
+    static constexpr auto name = const_name < std::is_same<T, float>::value
+                                 || std::is_same<T, const float>::value
+                                 || std::is_same<T, double>::value
+                                 || std::is_same<T, const double>::value
+                                        > (const_name("numpy.float") + const_name<sizeof(T) * 8>(),
+                                           const_name("numpy.longdouble"));
 };
 
 template <typename T>
 struct npy_format_descriptor_name<T, enable_if_t<is_complex<T>::value>> {
-    static constexpr auto name = const_name<std::is_same<typename T::value_type, float>::value
-                                   || std::is_same<typename T::value_type, const float>::value
-                                   || std::is_same<typename T::value_type, double>::value
-                                   || std::is_same<typename T::value_type, const double>::value>(
-        const_name("numpy.complex") + const_name<sizeof(typename T::value_type)*16>(), const_name("numpy.longcomplex")
-    );
+    static constexpr auto name = const_name < std::is_same<typename T::value_type, float>::value
+                                 || std::is_same<typename T::value_type, const float>::value
+                                 || std::is_same<typename T::value_type, double>::value
+                                 || std::is_same<typename T::value_type, const double>::value
+                                        > (const_name("numpy.complex")
+                                               + const_name<sizeof(typename T::value_type) * 16>(),
+                                           const_name("numpy.longcomplex"));
 };
 
 template <typename T>
-struct npy_format_descriptor<T, enable_if_t<satisfies_any_of<T, std::is_arithmetic, is_complex>::value>>
+struct npy_format_descriptor<
+    T,
+    enable_if_t<satisfies_any_of<T, std::is_arithmetic, is_complex>::value>>
     : npy_format_descriptor_name<T> {
 private:
     // NB: the order here must match the one in common.h
-    constexpr static const int values[15] = {
-        npy_api::NPY_BOOL_,
-        npy_api::NPY_BYTE_,   npy_api::NPY_UBYTE_,   npy_api::NPY_INT16_,    npy_api::NPY_UINT16_,
-        npy_api::NPY_INT32_,  npy_api::NPY_UINT32_,  npy_api::NPY_INT64_,    npy_api::NPY_UINT64_,
-        npy_api::NPY_FLOAT_,  npy_api::NPY_DOUBLE_,  npy_api::NPY_LONGDOUBLE_,
-        npy_api::NPY_CFLOAT_, npy_api::NPY_CDOUBLE_, npy_api::NPY_CLONGDOUBLE_
-    };
+    constexpr static const int values[15] = {npy_api::NPY_BOOL_,
+                                             npy_api::NPY_BYTE_,
+                                             npy_api::NPY_UBYTE_,
+                                             npy_api::NPY_INT16_,
+                                             npy_api::NPY_UINT16_,
+                                             npy_api::NPY_INT32_,
+                                             npy_api::NPY_UINT32_,
+                                             npy_api::NPY_INT64_,
+                                             npy_api::NPY_UINT64_,
+                                             npy_api::NPY_FLOAT_,
+                                             npy_api::NPY_DOUBLE_,
+                                             npy_api::NPY_LONGDOUBLE_,
+                                             npy_api::NPY_CFLOAT_,
+                                             npy_api::NPY_CDOUBLE_,
+                                             npy_api::NPY_CLONGDOUBLE_};
 
 public:
     static constexpr int value = values[detail::is_fmt_numeric<T>::index];
 
     static pybind11::dtype dtype() {
-        if (auto ptr = npy_api::get().PyArray_DescrFromType_(value))
+        if (auto *ptr = npy_api::get().PyArray_DescrFromType_(value))
             return reinterpret_steal<pybind11::dtype>(ptr);
         pybind11_fail("Unsupported buffer format!");
     }
 };
 
-#define PYBIND11_DECL_CHAR_FMT \
-    static constexpr auto name = const_name("S") + const_name<N>(); \
-    static pybind11::dtype dtype() { return pybind11::dtype(std::string("S") + std::to_string(N)); }
-template <size_t N> struct npy_format_descriptor<char[N]> { PYBIND11_DECL_CHAR_FMT };
-template <size_t N> struct npy_format_descriptor<std::array<char, N>> { PYBIND11_DECL_CHAR_FMT };
+#define PYBIND11_DECL_CHAR_FMT                                                                    \
+    static constexpr auto name = const_name("S") + const_name<N>();                               \
+    static pybind11::dtype dtype() {                                                              \
+        return pybind11::dtype(std::string("S") + std::to_string(N));                             \
+    }
+template <size_t N>
+struct npy_format_descriptor<char[N]> {
+    PYBIND11_DECL_CHAR_FMT
+};
+template <size_t N>
+struct npy_format_descriptor<std::array<char, N>> {
+    PYBIND11_DECL_CHAR_FMT
+};
 #undef PYBIND11_DECL_CHAR_FMT
 
-template<typename T> struct npy_format_descriptor<T, enable_if_t<array_info<T>::is_array>> {
+template <typename T>
+struct npy_format_descriptor<T, enable_if_t<array_info<T>::is_array>> {
 private:
     using base_descr = npy_format_descriptor<typename array_info<T>::type>;
+
 public:
     static_assert(!array_info<T>::is_empty, "Zero-sized arrays are not supported");
 
-    static constexpr auto name = const_name("(") + array_info<T>::extents + const_name(")") + base_descr::name;
+    static constexpr auto name
+        = const_name("(") + array_info<T>::extents + const_name(")") + base_descr::name;
     static pybind11::dtype dtype() {
         list shape;
         array_info<T>::append_extents(shape);
@@ -1125,9 +1267,11 @@ template<typename T> struct npy_format_descriptor<T, enable_if_t<array_info<T>::
     }
 };
 
-template<typename T> struct npy_format_descriptor<T, enable_if_t<std::is_enum<T>::value>> {
+template <typename T>
+struct npy_format_descriptor<T, enable_if_t<std::is_enum<T>::value>> {
 private:
     using base_descr = npy_format_descriptor<typename std::underlying_type<T>::type>;
+
 public:
     static constexpr auto name = base_descr::name;
     static pybind11::dtype dtype() { return base_descr::dtype(); }
@@ -1141,31 +1285,33 @@ struct field_descriptor {
     dtype descr;
 };
 
-PYBIND11_NOINLINE void register_structured_dtype(
-    any_container<field_descriptor> fields,
-    const std::type_info& tinfo, ssize_t itemsize,
-    bool (*direct_converter)(PyObject *, void *&)) {
+PYBIND11_NOINLINE void register_structured_dtype(any_container<field_descriptor> fields,
+                                                 const std::type_info &tinfo,
+                                                 ssize_t itemsize,
+                                                 bool (*direct_converter)(PyObject *, void *&)) {
 
-    auto& numpy_internals = get_numpy_internals();
+    auto &numpy_internals = get_numpy_internals();
     if (numpy_internals.get_type_info(tinfo, false))
         pybind11_fail("NumPy: dtype is already registered");
 
     // Use ordered fields because order matters as of NumPy 1.14:
     // https://docs.scipy.org/doc/numpy/release.html#multiple-field-indexing-assignment-of-structured-arrays
     std::vector<field_descriptor> ordered_fields(std::move(fields));
-    std::sort(ordered_fields.begin(), ordered_fields.end(),
+    std::sort(
+        ordered_fields.begin(),
+        ordered_fields.end(),
         [](const field_descriptor &a, const field_descriptor &b) { return a.offset < b.offset; });
 
     list names, formats, offsets;
-    for (auto& field : ordered_fields) {
+    for (auto &field : ordered_fields) {
         if (!field.descr)
-            pybind11_fail(std::string("NumPy: unsupported field dtype: `") +
-                            field.name + "` @ " + tinfo.name());
+            pybind11_fail(std::string("NumPy: unsupported field dtype: `") + field.name + "` @ "
+                          + tinfo.name());
         names.append(PYBIND11_STR_TYPE(field.name));
         formats.append(field.descr);
         offsets.append(pybind11::int_(field.offset));
     }
-    auto dtype_ptr
+    auto *dtype_ptr
         = pybind11::dtype(std::move(names), std::move(formats), std::move(offsets), itemsize)
               .release()
               .ptr();
@@ -1185,7 +1331,7 @@ PYBIND11_NOINLINE void register_structured_dtype(
     // overriding the endianness. Putting the ^ in front of individual fields
     // isn't guaranteed to work due to https://github.com/numpy/numpy/issues/9049
     oss << "^T{";
-    for (auto& field : ordered_fields) {
+    for (auto &field : ordered_fields) {
         if (field.offset > offset)
             oss << (field.offset - offset) << 'x';
         oss << field.format << ':' << field.name << ':';
@@ -1197,24 +1343,24 @@ PYBIND11_NOINLINE void register_structured_dtype(
     auto format_str = oss.str();
 
     // Sanity check: verify that NumPy properly parses our buffer format string
-    auto& api = npy_api::get();
-    auto arr =  array(buffer_info(nullptr, itemsize, format_str, 1));
+    auto &api = npy_api::get();
+    auto arr = array(buffer_info(nullptr, itemsize, format_str, 1));
     if (!api.PyArray_EquivTypes_(dtype_ptr, arr.dtype().ptr()))
         pybind11_fail("NumPy: invalid buffer descriptor!");
 
     auto tindex = std::type_index(tinfo);
-    numpy_internals.registered_dtypes[tindex] = { dtype_ptr, format_str };
+    numpy_internals.registered_dtypes[tindex] = {dtype_ptr, format_str};
     get_internals().direct_conversions[tindex].push_back(direct_converter);
 }
 
-template <typename T, typename SFINAE> struct npy_format_descriptor {
-    static_assert(is_pod_struct<T>::value, "Attempt to use a non-POD or unimplemented POD type as a numpy dtype");
+template <typename T, typename SFINAE>
+struct npy_format_descriptor {
+    static_assert(is_pod_struct<T>::value,
+                  "Attempt to use a non-POD or unimplemented POD type as a numpy dtype");
 
     static constexpr auto name = make_caster<T>::name;
 
-    static pybind11::dtype dtype() {
-        return reinterpret_borrow<pybind11::dtype>(dtype_ptr());
-    }
+    static pybind11::dtype dtype() { return reinterpret_borrow<pybind11::dtype>(dtype_ptr()); }
 
     static std::string format() {
         static auto format_str = get_numpy_internals().get_type_info<T>(true)->format_str;
@@ -1222,18 +1368,20 @@ template <typename T, typename SFINAE> struct npy_format_descriptor {
     }
 
     static void register_dtype(any_container<field_descriptor> fields) {
-        register_structured_dtype(std::move(fields), typeid(typename std::remove_cv<T>::type),
-                                  sizeof(T), &direct_converter);
+        register_structured_dtype(std::move(fields),
+                                  typeid(typename std::remove_cv<T>::type),
+                                  sizeof(T),
+                                  &direct_converter);
     }
 
 private:
-    static PyObject* dtype_ptr() {
-        static PyObject* ptr = get_numpy_internals().get_type_info<T>(true)->dtype_ptr;
+    static PyObject *dtype_ptr() {
+        static PyObject *ptr = get_numpy_internals().get_type_info<T>(true)->dtype_ptr;
         return ptr;
     }
 
-    static bool direct_converter(PyObject *obj, void*& value) {
-        auto& api = npy_api::get();
+    static bool direct_converter(PyObject *obj, void *&value) {
+        auto &api = npy_api::get();
         if (!PyObject_TypeCheck(obj, api.PyVoidArrType_Type_))
             return false;
         if (auto descr = reinterpret_steal<object>(api.PyArray_DescrFromScalar_(obj))) {
@@ -1247,78 +1395,80 @@ template <typename T, typename SFINAE> struct npy_format_descriptor {
 };
 
 #ifdef __CLION_IDE__ // replace heavy macro with dummy code for the IDE (doesn't affect code)
-# define PYBIND11_NUMPY_DTYPE(Type, ...) ((void)0)
-# define PYBIND11_NUMPY_DTYPE_EX(Type, ...) ((void)0)
+#    define PYBIND11_NUMPY_DTYPE(Type, ...) ((void) 0)
+#    define PYBIND11_NUMPY_DTYPE_EX(Type, ...) ((void) 0)
 #else
 
-#define PYBIND11_FIELD_DESCRIPTOR_EX(T, Field, Name)                                          \
-    ::pybind11::detail::field_descriptor {                                                    \
-        Name, offsetof(T, Field), sizeof(decltype(std::declval<T>().Field)),                  \
-        ::pybind11::format_descriptor<decltype(std::declval<T>().Field)>::format(),           \
-        ::pybind11::detail::npy_format_descriptor<decltype(std::declval<T>().Field)>::dtype() \
-    }
+#    define PYBIND11_FIELD_DESCRIPTOR_EX(T, Field, Name)                                          \
+        ::pybind11::detail::field_descriptor {                                                    \
+            Name, offsetof(T, Field), sizeof(decltype(std::declval<T>().Field)),                  \
+                ::pybind11::format_descriptor<decltype(std::declval<T>().Field)>::format(),       \
+                ::pybind11::detail::npy_format_descriptor<                                        \
+                    decltype(std::declval<T>().Field)>::dtype()                                   \
+        }
 
 // Extract name, offset and format descriptor for a struct field
-#define PYBIND11_FIELD_DESCRIPTOR(T, Field) PYBIND11_FIELD_DESCRIPTOR_EX(T, Field, #Field)
+#    define PYBIND11_FIELD_DESCRIPTOR(T, Field) PYBIND11_FIELD_DESCRIPTOR_EX(T, Field, #    Field)
 
 // The main idea of this macro is borrowed from https://github.com/swansontec/map-macro
 // (C) William Swanson, Paul Fultz
-#define PYBIND11_EVAL0(...) __VA_ARGS__
-#define PYBIND11_EVAL1(...) PYBIND11_EVAL0 (PYBIND11_EVAL0 (PYBIND11_EVAL0 (__VA_ARGS__)))
-#define PYBIND11_EVAL2(...) PYBIND11_EVAL1 (PYBIND11_EVAL1 (PYBIND11_EVAL1 (__VA_ARGS__)))
-#define PYBIND11_EVAL3(...) PYBIND11_EVAL2 (PYBIND11_EVAL2 (PYBIND11_EVAL2 (__VA_ARGS__)))
-#define PYBIND11_EVAL4(...) PYBIND11_EVAL3 (PYBIND11_EVAL3 (PYBIND11_EVAL3 (__VA_ARGS__)))
-#define PYBIND11_EVAL(...)  PYBIND11_EVAL4 (PYBIND11_EVAL4 (PYBIND11_EVAL4 (__VA_ARGS__)))
-#define PYBIND11_MAP_END(...)
-#define PYBIND11_MAP_OUT
-#define PYBIND11_MAP_COMMA ,
-#define PYBIND11_MAP_GET_END() 0, PYBIND11_MAP_END
-#define PYBIND11_MAP_NEXT0(test, next, ...) next PYBIND11_MAP_OUT
-#define PYBIND11_MAP_NEXT1(test, next) PYBIND11_MAP_NEXT0 (test, next, 0)
-#define PYBIND11_MAP_NEXT(test, next)  PYBIND11_MAP_NEXT1 (PYBIND11_MAP_GET_END test, next)
-#if defined(_MSC_VER) && !defined(__clang__) // MSVC is not as eager to expand macros, hence this workaround
-#define PYBIND11_MAP_LIST_NEXT1(test, next) \
-    PYBIND11_EVAL0 (PYBIND11_MAP_NEXT0 (test, PYBIND11_MAP_COMMA next, 0))
-#else
-#define PYBIND11_MAP_LIST_NEXT1(test, next) \
-    PYBIND11_MAP_NEXT0 (test, PYBIND11_MAP_COMMA next, 0)
-#endif
-#define PYBIND11_MAP_LIST_NEXT(test, next) \
-    PYBIND11_MAP_LIST_NEXT1 (PYBIND11_MAP_GET_END test, next)
-#define PYBIND11_MAP_LIST0(f, t, x, peek, ...) \
-    f(t, x) PYBIND11_MAP_LIST_NEXT (peek, PYBIND11_MAP_LIST1) (f, t, peek, __VA_ARGS__)
-#define PYBIND11_MAP_LIST1(f, t, x, peek, ...) \
-    f(t, x) PYBIND11_MAP_LIST_NEXT (peek, PYBIND11_MAP_LIST0) (f, t, peek, __VA_ARGS__)
+#    define PYBIND11_EVAL0(...) __VA_ARGS__
+#    define PYBIND11_EVAL1(...) PYBIND11_EVAL0(PYBIND11_EVAL0(PYBIND11_EVAL0(__VA_ARGS__)))
+#    define PYBIND11_EVAL2(...) PYBIND11_EVAL1(PYBIND11_EVAL1(PYBIND11_EVAL1(__VA_ARGS__)))
+#    define PYBIND11_EVAL3(...) PYBIND11_EVAL2(PYBIND11_EVAL2(PYBIND11_EVAL2(__VA_ARGS__)))
+#    define PYBIND11_EVAL4(...) PYBIND11_EVAL3(PYBIND11_EVAL3(PYBIND11_EVAL3(__VA_ARGS__)))
+#    define PYBIND11_EVAL(...) PYBIND11_EVAL4(PYBIND11_EVAL4(PYBIND11_EVAL4(__VA_ARGS__)))
+#    define PYBIND11_MAP_END(...)
+#    define PYBIND11_MAP_OUT
+#    define PYBIND11_MAP_COMMA ,
+#    define PYBIND11_MAP_GET_END() 0, PYBIND11_MAP_END
+#    define PYBIND11_MAP_NEXT0(test, next, ...) next PYBIND11_MAP_OUT
+#    define PYBIND11_MAP_NEXT1(test, next) PYBIND11_MAP_NEXT0(test, next, 0)
+#    define PYBIND11_MAP_NEXT(test, next) PYBIND11_MAP_NEXT1(PYBIND11_MAP_GET_END test, next)
+#    if defined(_MSC_VER)                                                                         \
+        && !defined(__clang__) // MSVC is not as eager to expand macros, hence this workaround
+#        define PYBIND11_MAP_LIST_NEXT1(test, next)                                               \
+            PYBIND11_EVAL0(PYBIND11_MAP_NEXT0(test, PYBIND11_MAP_COMMA next, 0))
+#    else
+#        define PYBIND11_MAP_LIST_NEXT1(test, next)                                               \
+            PYBIND11_MAP_NEXT0(test, PYBIND11_MAP_COMMA next, 0)
+#    endif
+#    define PYBIND11_MAP_LIST_NEXT(test, next)                                                    \
+        PYBIND11_MAP_LIST_NEXT1(PYBIND11_MAP_GET_END test, next)
+#    define PYBIND11_MAP_LIST0(f, t, x, peek, ...)                                                \
+        f(t, x) PYBIND11_MAP_LIST_NEXT(peek, PYBIND11_MAP_LIST1)(f, t, peek, __VA_ARGS__)
+#    define PYBIND11_MAP_LIST1(f, t, x, peek, ...)                                                \
+        f(t, x) PYBIND11_MAP_LIST_NEXT(peek, PYBIND11_MAP_LIST0)(f, t, peek, __VA_ARGS__)
 // PYBIND11_MAP_LIST(f, t, a1, a2, ...) expands to f(t, a1), f(t, a2), ...
-#define PYBIND11_MAP_LIST(f, t, ...) \
-    PYBIND11_EVAL (PYBIND11_MAP_LIST1 (f, t, __VA_ARGS__, (), 0))
-
-#define PYBIND11_NUMPY_DTYPE(Type, ...) \
-    ::pybind11::detail::npy_format_descriptor<Type>::register_dtype \
-        (::std::vector<::pybind11::detail::field_descriptor> \
-         {PYBIND11_MAP_LIST (PYBIND11_FIELD_DESCRIPTOR, Type, __VA_ARGS__)})
-
-#if defined(_MSC_VER) && !defined(__clang__)
-#define PYBIND11_MAP2_LIST_NEXT1(test, next) \
-    PYBIND11_EVAL0 (PYBIND11_MAP_NEXT0 (test, PYBIND11_MAP_COMMA next, 0))
-#else
-#define PYBIND11_MAP2_LIST_NEXT1(test, next) \
-    PYBIND11_MAP_NEXT0 (test, PYBIND11_MAP_COMMA next, 0)
-#endif
-#define PYBIND11_MAP2_LIST_NEXT(test, next) \
-    PYBIND11_MAP2_LIST_NEXT1 (PYBIND11_MAP_GET_END test, next)
-#define PYBIND11_MAP2_LIST0(f, t, x1, x2, peek, ...) \
-    f(t, x1, x2) PYBIND11_MAP2_LIST_NEXT (peek, PYBIND11_MAP2_LIST1) (f, t, peek, __VA_ARGS__)
-#define PYBIND11_MAP2_LIST1(f, t, x1, x2, peek, ...) \
-    f(t, x1, x2) PYBIND11_MAP2_LIST_NEXT (peek, PYBIND11_MAP2_LIST0) (f, t, peek, __VA_ARGS__)
+#    define PYBIND11_MAP_LIST(f, t, ...)                                                          \
+        PYBIND11_EVAL(PYBIND11_MAP_LIST1(f, t, __VA_ARGS__, (), 0))
+
+#    define PYBIND11_NUMPY_DTYPE(Type, ...)                                                       \
+        ::pybind11::detail::npy_format_descriptor<Type>::register_dtype(                          \
+            ::std::vector<::pybind11::detail::field_descriptor>{                                  \
+                PYBIND11_MAP_LIST(PYBIND11_FIELD_DESCRIPTOR, Type, __VA_ARGS__)})
+
+#    if defined(_MSC_VER) && !defined(__clang__)
+#        define PYBIND11_MAP2_LIST_NEXT1(test, next)                                              \
+            PYBIND11_EVAL0(PYBIND11_MAP_NEXT0(test, PYBIND11_MAP_COMMA next, 0))
+#    else
+#        define PYBIND11_MAP2_LIST_NEXT1(test, next)                                              \
+            PYBIND11_MAP_NEXT0(test, PYBIND11_MAP_COMMA next, 0)
+#    endif
+#    define PYBIND11_MAP2_LIST_NEXT(test, next)                                                   \
+        PYBIND11_MAP2_LIST_NEXT1(PYBIND11_MAP_GET_END test, next)
+#    define PYBIND11_MAP2_LIST0(f, t, x1, x2, peek, ...)                                          \
+        f(t, x1, x2) PYBIND11_MAP2_LIST_NEXT(peek, PYBIND11_MAP2_LIST1)(f, t, peek, __VA_ARGS__)
+#    define PYBIND11_MAP2_LIST1(f, t, x1, x2, peek, ...)                                          \
+        f(t, x1, x2) PYBIND11_MAP2_LIST_NEXT(peek, PYBIND11_MAP2_LIST0)(f, t, peek, __VA_ARGS__)
 // PYBIND11_MAP2_LIST(f, t, a1, a2, ...) expands to f(t, a1, a2), f(t, a3, a4), ...
-#define PYBIND11_MAP2_LIST(f, t, ...) \
-    PYBIND11_EVAL (PYBIND11_MAP2_LIST1 (f, t, __VA_ARGS__, (), 0))
+#    define PYBIND11_MAP2_LIST(f, t, ...)                                                         \
+        PYBIND11_EVAL(PYBIND11_MAP2_LIST1(f, t, __VA_ARGS__, (), 0))
 
-#define PYBIND11_NUMPY_DTYPE_EX(Type, ...) \
-    ::pybind11::detail::npy_format_descriptor<Type>::register_dtype \
-        (::std::vector<::pybind11::detail::field_descriptor> \
-         {PYBIND11_MAP2_LIST (PYBIND11_FIELD_DESCRIPTOR_EX, Type, __VA_ARGS__)})
+#    define PYBIND11_NUMPY_DTYPE_EX(Type, ...)                                                    \
+        ::pybind11::detail::npy_format_descriptor<Type>::register_dtype(                          \
+            ::std::vector<::pybind11::detail::field_descriptor>{                                  \
+                PYBIND11_MAP2_LIST(PYBIND11_FIELD_DESCRIPTOR_EX, Type, __VA_ARGS__)})
 
 #endif // __CLION_IDE__
 
@@ -1330,8 +1480,8 @@ class common_iterator {
 
     common_iterator() : m_strides() {}
 
-    common_iterator(void* ptr, const container_type& strides, const container_type& shape)
-        : p_ptr(reinterpret_cast<char*>(ptr)), m_strides(strides.size()) {
+    common_iterator(void *ptr, const container_type &strides, const container_type &shape)
+        : p_ptr(reinterpret_cast<char *>(ptr)), m_strides(strides.size()) {
         m_strides.back() = static_cast<value_type>(strides.back());
         for (size_type i = m_strides.size() - 1; i != 0; --i) {
             size_type j = i - 1;
@@ -1340,27 +1490,22 @@ class common_iterator {
         }
     }
 
-    void increment(size_type dim) {
-        p_ptr += m_strides[dim];
-    }
+    void increment(size_type dim) { p_ptr += m_strides[dim]; }
 
-    void* data() const {
-        return p_ptr;
-    }
+    void *data() const { return p_ptr; }
 
 private:
     char *p_ptr{0};
     container_type m_strides;
 };
 
-template <size_t N> class multi_array_iterator {
+template <size_t N>
+class multi_array_iterator {
 public:
     using container_type = std::vector<ssize_t>;
 
-    multi_array_iterator(const std::array<buffer_info, N> &buffers,
-                         const container_type &shape)
-        : m_shape(shape.size()), m_index(shape.size(), 0),
-          m_common_iterator() {
+    multi_array_iterator(const std::array<buffer_info, N> &buffers, const container_type &shape)
+        : m_shape(shape.size()), m_index(shape.size(), 0), m_common_iterator() {
 
         // Manual copy to avoid conversion warning if using std::copy
         for (size_t i = 0; i < shape.size(); ++i)
@@ -1371,7 +1516,7 @@ template <size_t N> class multi_array_iterator {
             init_common_iterator(buffers[i], shape, m_common_iterator[i], strides);
     }
 
-    multi_array_iterator& operator++() {
+    multi_array_iterator &operator++() {
         for (size_t j = m_index.size(); j != 0; --j) {
             size_t i = j - 1;
             if (++m_index[i] != m_shape[i]) {
@@ -1383,12 +1528,12 @@ template <size_t N> class multi_array_iterator {
         return *this;
     }
 
-    template <size_t K, class T = void> T* data() const {
-        return reinterpret_cast<T*>(m_common_iterator[K].data());
+    template <size_t K, class T = void>
+    T *data() const {
+        return reinterpret_cast<T *>(m_common_iterator[K].data());
     }
 
 private:
-
     using common_iter = common_iterator;
 
     void init_common_iterator(const buffer_info &buffer,
@@ -1428,29 +1573,33 @@ template <size_t N> class multi_array_iterator {
 
 enum class broadcast_trivial { non_trivial, c_trivial, f_trivial };
 
-// Populates the shape and number of dimensions for the set of buffers.  Returns a broadcast_trivial
-// enum value indicating whether the broadcast is "trivial"--that is, has each buffer being either a
-// singleton or a full-size, C-contiguous (`c_trivial`) or Fortran-contiguous (`f_trivial`) storage
-// buffer; returns `non_trivial` otherwise.
+// Populates the shape and number of dimensions for the set of buffers.  Returns a
+// broadcast_trivial enum value indicating whether the broadcast is "trivial"--that is, has each
+// buffer being either a singleton or a full-size, C-contiguous (`c_trivial`) or Fortran-contiguous
+// (`f_trivial`) storage buffer; returns `non_trivial` otherwise.
 template <size_t N>
-broadcast_trivial broadcast(const std::array<buffer_info, N> &buffers, ssize_t &ndim, std::vector<ssize_t> &shape) {
-    ndim = std::accumulate(buffers.begin(), buffers.end(), ssize_t(0), [](ssize_t res, const buffer_info &buf) {
-        return std::max(res, buf.ndim);
-    });
+broadcast_trivial
+broadcast(const std::array<buffer_info, N> &buffers, ssize_t &ndim, std::vector<ssize_t> &shape) {
+    ndim = std::accumulate(
+        buffers.begin(), buffers.end(), ssize_t(0), [](ssize_t res, const buffer_info &buf) {
+            return std::max(res, buf.ndim);
+        });
 
     shape.clear();
     shape.resize((size_t) ndim, 1);
 
-    // Figure out the output size, and make sure all input arrays conform (i.e. are either size 1 or
-    // the full size).
+    // Figure out the output size, and make sure all input arrays conform (i.e. are either size 1
+    // or the full size).
     for (size_t i = 0; i < N; ++i) {
         auto res_iter = shape.rbegin();
         auto end = buffers[i].shape.rend();
-        for (auto shape_iter = buffers[i].shape.rbegin(); shape_iter != end; ++shape_iter, ++res_iter) {
+        for (auto shape_iter = buffers[i].shape.rbegin(); shape_iter != end;
+             ++shape_iter, ++res_iter) {
             const auto &dim_size_in = *shape_iter;
             auto &dim_size_out = *res_iter;
 
-            // Each input dimension can either be 1 or `n`, but `n` values must match across buffers
+            // Each input dimension can either be 1 or `n`, but `n` values must match across
+            // buffers
             if (dim_size_out == 1)
                 dim_size_out = dim_size_in;
             else if (dim_size_in != 1 && dim_size_in != dim_size_out)
@@ -1476,8 +1625,10 @@ broadcast_trivial broadcast(const std::array<buffer_info, N> &buffers, ssize_t &
         if (trivial_broadcast_c) {
             ssize_t expect_stride = buffers[i].itemsize;
             auto end = buffers[i].shape.crend();
-            for (auto shape_iter = buffers[i].shape.crbegin(), stride_iter = buffers[i].strides.crbegin();
-                    trivial_broadcast_c && shape_iter != end; ++shape_iter, ++stride_iter) {
+            for (auto shape_iter = buffers[i].shape.crbegin(),
+                      stride_iter = buffers[i].strides.crbegin();
+                 trivial_broadcast_c && shape_iter != end;
+                 ++shape_iter, ++stride_iter) {
                 if (expect_stride == *stride_iter)
                     expect_stride *= *shape_iter;
                 else
@@ -1489,8 +1640,10 @@ broadcast_trivial broadcast(const std::array<buffer_info, N> &buffers, ssize_t &
         if (trivial_broadcast_f) {
             ssize_t expect_stride = buffers[i].itemsize;
             auto end = buffers[i].shape.cend();
-            for (auto shape_iter = buffers[i].shape.cbegin(), stride_iter = buffers[i].strides.cbegin();
-                    trivial_broadcast_f && shape_iter != end; ++shape_iter, ++stride_iter) {
+            for (auto shape_iter = buffers[i].shape.cbegin(),
+                      stride_iter = buffers[i].strides.cbegin();
+                 trivial_broadcast_f && shape_iter != end;
+                 ++shape_iter, ++stride_iter) {
                 if (expect_stride == *stride_iter)
                     expect_stride *= *shape_iter;
                 else
@@ -1499,28 +1652,31 @@ broadcast_trivial broadcast(const std::array<buffer_info, N> &buffers, ssize_t &
         }
     }
 
-    return
-        trivial_broadcast_c ? broadcast_trivial::c_trivial :
-        trivial_broadcast_f ? broadcast_trivial::f_trivial :
-        broadcast_trivial::non_trivial;
+    return trivial_broadcast_c   ? broadcast_trivial::c_trivial
+           : trivial_broadcast_f ? broadcast_trivial::f_trivial
+                                 : broadcast_trivial::non_trivial;
 }
 
 template <typename T>
 struct vectorize_arg {
-    static_assert(!std::is_rvalue_reference<T>::value, "Functions with rvalue reference arguments cannot be vectorized");
+    static_assert(!std::is_rvalue_reference<T>::value,
+                  "Functions with rvalue reference arguments cannot be vectorized");
     // The wrapped function gets called with this type:
     using call_type = remove_reference_t<T>;
     // Is this a vectorized argument?
-    static constexpr bool vectorize =
-        satisfies_any_of<call_type, std::is_arithmetic, is_complex, is_pod>::value &&
-        satisfies_none_of<call_type, std::is_pointer, std::is_array, is_std_array, std::is_enum>::value &&
-        (!std::is_reference<T>::value ||
-         (std::is_lvalue_reference<T>::value && std::is_const<call_type>::value));
+    static constexpr bool vectorize
+        = satisfies_any_of<call_type, std::is_arithmetic, is_complex, is_pod>::value
+          && satisfies_none_of<call_type,
+                               std::is_pointer,
+                               std::is_array,
+                               is_std_array,
+                               std::is_enum>::value
+          && (!std::is_reference<T>::value
+              || (std::is_lvalue_reference<T>::value && std::is_const<call_type>::value));
     // Accept this type: an array for vectorized types, otherwise the type as-is:
     using type = conditional_t<vectorize, array_t<remove_cv_t<call_type>, array::forcecast>, T>;
 };
 
-
 // py::vectorize when a return type is present
 template <typename Func, typename Return, typename... Args>
 struct vectorize_returned_array {
@@ -1532,17 +1688,11 @@ struct vectorize_returned_array {
         return array_t<Return>(shape);
     }
 
-    static Return *mutable_data(Type &array) {
-        return array.mutable_data();
-    }
+    static Return *mutable_data(Type &array) { return array.mutable_data(); }
 
-    static Return call(Func &f, Args &... args) {
-        return f(args...);
-    }
+    static Return call(Func &f, Args &...args) { return f(args...); }
 
-    static void call(Return *out, size_t i, Func &f, Args &... args) {
-        out[i] = f(args...);
-    }
+    static void call(Return *out, size_t i, Func &f, Args &...args) { out[i] = f(args...); }
 };
 
 // py::vectorize when a return type is not present
@@ -1550,25 +1700,18 @@ template <typename Func, typename... Args>
 struct vectorize_returned_array<Func, void, Args...> {
     using Type = none;
 
-    static Type create(broadcast_trivial, const std::vector<ssize_t> &) {
-        return none();
-    }
+    static Type create(broadcast_trivial, const std::vector<ssize_t> &) { return none(); }
 
-    static void *mutable_data(Type &) {
-        return nullptr;
-    }
+    static void *mutable_data(Type &) { return nullptr; }
 
-    static detail::void_type call(Func &f, Args &... args) {
+    static detail::void_type call(Func &f, Args &...args) {
         f(args...);
         return {};
     }
 
-    static void call(void *, size_t, Func &f, Args &... args) {
-        f(args...);
-    }
+    static void call(void *, size_t, Func &f, Args &...args) { f(args...); }
 };
 
-
 template <typename Func, typename Return, typename... Args>
 struct vectorize_helper {
 
@@ -1581,8 +1724,9 @@ struct vectorize_helper {
 
     static constexpr size_t N = sizeof...(Args);
     static constexpr size_t NVectorized = constexpr_sum(vectorize_arg<Args>::vectorize...);
-    static_assert(NVectorized >= 1,
-            "pybind11::vectorize(...) requires a function with at least one vectorizable argument");
+    static_assert(
+        NVectorized >= 1,
+        "pybind11::vectorize(...) requires a function with at least one vectorizable argument");
 
 public:
     template <typename T,
@@ -1601,10 +1745,11 @@ struct vectorize_helper {
 private:
     remove_reference_t<Func> f;
 
-    // Internal compiler error in MSVC 19.16.27025.1 (Visual Studio 2017 15.9.4), when compiling with "/permissive-" flag
-    // when arg_call_types is manually inlined.
+    // Internal compiler error in MSVC 19.16.27025.1 (Visual Studio 2017 15.9.4), when compiling
+    // with "/permissive-" flag when arg_call_types is manually inlined.
     using arg_call_types = std::tuple<typename vectorize_arg<Args>::call_type...>;
-    template <size_t Index> using param_n_t = typename std::tuple_element<Index, arg_call_types>::type;
+    template <size_t Index>
+    using param_n_t = typename std::tuple_element<Index, arg_call_types>::type;
 
     using returned_array = vectorize_returned_array<Func, Return, Args...>;
 
@@ -1615,17 +1760,20 @@ struct vectorize_helper {
     //     - BIndex is a incremental sequence (beginning at 0) of the same size as VIndex, so that
     //       we can store vectorized buffer_infos in an array (argument VIndex has its buffer at
     //       index BIndex in the array).
-    template <size_t... Index, size_t... VIndex, size_t... BIndex> object run(
-            typename vectorize_arg<Args>::type &...args,
-            index_sequence<Index...> i_seq, index_sequence<VIndex...> vi_seq, index_sequence<BIndex...> bi_seq) {
+    template <size_t... Index, size_t... VIndex, size_t... BIndex>
+    object run(typename vectorize_arg<Args>::type &...args,
+               index_sequence<Index...> i_seq,
+               index_sequence<VIndex...> vi_seq,
+               index_sequence<BIndex...> bi_seq) {
 
         // Pointers to values the function was called with; the vectorized ones set here will start
         // out as array_t<T> pointers, but they will be changed them to T pointers before we make
         // call the wrapped function.  Non-vectorized pointers are left as-is.
-        std::array<void *, N> params{{ &args... }};
+        std::array<void *, N> params{{&args...}};
 
         // The array of `buffer_info`s of vectorized arguments:
-        std::array<buffer_info, NVectorized> buffers{{ reinterpret_cast<array *>(params[VIndex])->request()... }};
+        std::array<buffer_info, NVectorized> buffers{
+            {reinterpret_cast<array *>(params[VIndex])->request()...}};
 
         /* Determine dimensions parameters of output array */
         ssize_t nd = 0;
@@ -1633,21 +1781,24 @@ struct vectorize_helper {
         auto trivial = broadcast(buffers, nd, shape);
         auto ndim = (size_t) nd;
 
-        size_t size = std::accumulate(shape.begin(), shape.end(), (size_t) 1, std::multiplies<size_t>());
+        size_t size
+            = std::accumulate(shape.begin(), shape.end(), (size_t) 1, std::multiplies<size_t>());
 
         // If all arguments are 0-dimension arrays (i.e. single values) return a plain value (i.e.
         // not wrapped in an array).
         if (size == 1 && ndim == 0) {
             PYBIND11_EXPAND_SIDE_EFFECTS(params[VIndex] = buffers[BIndex].ptr);
-            return cast(returned_array::call(f, *reinterpret_cast<param_n_t<Index> *>(params[Index])...));
+            return cast(
+                returned_array::call(f, *reinterpret_cast<param_n_t<Index> *>(params[Index])...));
         }
 
         auto result = returned_array::create(trivial, shape);
 
-        if (size == 0) return std::move(result);
+        if (size == 0)
+            return std::move(result);
 
         /* Call the function */
-        auto mutable_data = returned_array::mutable_data(result);
+        auto *mutable_data = returned_array::mutable_data(result);
         if (trivial == broadcast_trivial::non_trivial)
             apply_broadcast(buffers, params, mutable_data, size, shape, i_seq, vi_seq, bi_seq);
         else
@@ -1661,21 +1812,23 @@ struct vectorize_helper {
                        std::array<void *, N> &params,
                        Return *out,
                        size_t size,
-                       index_sequence<Index...>, index_sequence<VIndex...>, index_sequence<BIndex...>) {
+                       index_sequence<Index...>,
+                       index_sequence<VIndex...>,
+                       index_sequence<BIndex...>) {
 
         // Initialize an array of mutable byte references and sizes with references set to the
         // appropriate pointer in `params`; as we iterate, we'll increment each pointer by its size
         // (except for singletons, which get an increment of 0).
-        std::array<std::pair<unsigned char *&, const size_t>, NVectorized> vecparams{{
-            std::pair<unsigned char *&, const size_t>(
-                    reinterpret_cast<unsigned char *&>(params[VIndex] = buffers[BIndex].ptr),
-                    buffers[BIndex].size == 1 ? 0 : sizeof(param_n_t<VIndex>)
-            )...
-        }};
+        std::array<std::pair<unsigned char *&, const size_t>, NVectorized> vecparams{
+            {std::pair<unsigned char *&, const size_t>(
+                reinterpret_cast<unsigned char *&>(params[VIndex] = buffers[BIndex].ptr),
+                buffers[BIndex].size == 1 ? 0 : sizeof(param_n_t<VIndex>))...}};
 
         for (size_t i = 0; i < size; ++i) {
-            returned_array::call(out, i, f, *reinterpret_cast<param_n_t<Index> *>(params[Index])...);
-            for (auto &x : vecparams) x.first += x.second;
+            returned_array::call(
+                out, i, f, *reinterpret_cast<param_n_t<Index> *>(params[Index])...);
+            for (auto &x : vecparams)
+                x.first += x.second;
         }
     }
 
@@ -1685,55 +1838,70 @@ struct vectorize_helper {
                          Return *out,
                          size_t size,
                          const std::vector<ssize_t> &output_shape,
-                         index_sequence<Index...>, index_sequence<VIndex...>, index_sequence<BIndex...>) {
+                         index_sequence<Index...>,
+                         index_sequence<VIndex...>,
+                         index_sequence<BIndex...>) {
 
         multi_array_iterator<NVectorized> input_iter(buffers, output_shape);
 
         for (size_t i = 0; i < size; ++i, ++input_iter) {
-            PYBIND11_EXPAND_SIDE_EFFECTS((
-                params[VIndex] = input_iter.template data<BIndex>()
-            ));
-            returned_array::call(out, i, f, *reinterpret_cast<param_n_t<Index> *>(std::get<Index>(params))...);
+            PYBIND11_EXPAND_SIDE_EFFECTS((params[VIndex] = input_iter.template data<BIndex>()));
+            returned_array::call(
+                out, i, f, *reinterpret_cast<param_n_t<Index> *>(std::get<Index>(params))...);
         }
     }
 };
 
 template <typename Func, typename Return, typename... Args>
-vectorize_helper<Func, Return, Args...>
-vectorize_extractor(const Func &f, Return (*) (Args ...)) {
+vectorize_helper<Func, Return, Args...> vectorize_extractor(const Func &f, Return (*)(Args...)) {
     return detail::vectorize_helper<Func, Return, Args...>(f);
 }
 
-template <typename T, int Flags> struct handle_type_name<array_t<T, Flags>> {
-    static constexpr auto name = const_name("numpy.ndarray[") + npy_format_descriptor<T>::name + const_name("]");
+template <typename T, int Flags>
+struct handle_type_name<array_t<T, Flags>> {
+    static constexpr auto name
+        = const_name("numpy.ndarray[") + npy_format_descriptor<T>::name + const_name("]");
 };
 
 PYBIND11_NAMESPACE_END(detail)
 
 // Vanilla pointer vectorizer:
 template <typename Return, typename... Args>
-detail::vectorize_helper<Return (*)(Args...), Return, Args...>
-vectorize(Return (*f) (Args ...)) {
+detail::vectorize_helper<Return (*)(Args...), Return, Args...> vectorize(Return (*f)(Args...)) {
     return detail::vectorize_helper<Return (*)(Args...), Return, Args...>(f);
 }
 
 // lambda vectorizer:
 template <typename Func, detail::enable_if_t<detail::is_lambda<Func>::value, int> = 0>
-auto vectorize(Func &&f) -> decltype(
-        detail::vectorize_extractor(std::forward<Func>(f), (detail::function_signature_t<Func> *) nullptr)) {
-    return detail::vectorize_extractor(std::forward<Func>(f), (detail::function_signature_t<Func> *) nullptr);
+auto vectorize(Func &&f)
+    -> decltype(detail::vectorize_extractor(std::forward<Func>(f),
+                                            (detail::function_signature_t<Func> *) nullptr)) {
+    return detail::vectorize_extractor(std::forward<Func>(f),
+                                       (detail::function_signature_t<Func> *) nullptr);
 }
 
 // Vectorize a class method (non-const):
-template <typename Return, typename Class, typename... Args,
-          typename Helper = detail::vectorize_helper<decltype(std::mem_fn(std::declval<Return (Class::*)(Args...)>())), Return, Class *, Args...>>
+template <typename Return,
+          typename Class,
+          typename... Args,
+          typename Helper = detail::vectorize_helper<
+              decltype(std::mem_fn(std::declval<Return (Class::*)(Args...)>())),
+              Return,
+              Class *,
+              Args...>>
 Helper vectorize(Return (Class::*f)(Args...)) {
     return Helper(std::mem_fn(f));
 }
 
 // Vectorize a class method (const):
-template <typename Return, typename Class, typename... Args,
-          typename Helper = detail::vectorize_helper<decltype(std::mem_fn(std::declval<Return (Class::*)(Args...) const>())), Return, const Class *, Args...>>
+template <typename Return,
+          typename Class,
+          typename... Args,
+          typename Helper = detail::vectorize_helper<
+              decltype(std::mem_fn(std::declval<Return (Class::*)(Args...) const>())),
+              Return,
+              const Class *,
+              Args...>>
 Helper vectorize(Return (Class::*f)(Args...) const) {
     return Helper(std::mem_fn(f));
 }
diff --git a/include/pybind11/operators.h b/include/pybind11/operators.h
index 2a61531589..7865d35e10 100644
--- a/include/pybind11/operators.h
+++ b/include/pybind11/operators.h
@@ -16,12 +16,50 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 
 /// Enumeration with all supported operator types
 enum op_id : int {
-    op_add, op_sub, op_mul, op_div, op_mod, op_divmod, op_pow, op_lshift,
-    op_rshift, op_and, op_xor, op_or, op_neg, op_pos, op_abs, op_invert,
-    op_int, op_long, op_float, op_str, op_cmp, op_gt, op_ge, op_lt, op_le,
-    op_eq, op_ne, op_iadd, op_isub, op_imul, op_idiv, op_imod, op_ilshift,
-    op_irshift, op_iand, op_ixor, op_ior, op_complex, op_bool, op_nonzero,
-    op_repr, op_truediv, op_itruediv, op_hash
+    op_add,
+    op_sub,
+    op_mul,
+    op_div,
+    op_mod,
+    op_divmod,
+    op_pow,
+    op_lshift,
+    op_rshift,
+    op_and,
+    op_xor,
+    op_or,
+    op_neg,
+    op_pos,
+    op_abs,
+    op_invert,
+    op_int,
+    op_long,
+    op_float,
+    op_str,
+    op_cmp,
+    op_gt,
+    op_ge,
+    op_lt,
+    op_le,
+    op_eq,
+    op_ne,
+    op_iadd,
+    op_isub,
+    op_imul,
+    op_idiv,
+    op_imod,
+    op_ilshift,
+    op_irshift,
+    op_iand,
+    op_ixor,
+    op_ior,
+    op_complex,
+    op_bool,
+    op_nonzero,
+    op_repr,
+    op_truediv,
+    op_itruediv,
+    op_hash
 };
 
 enum op_type : int {
@@ -30,126 +68,145 @@ enum op_type : int {
     op_u  /* unary operator */
 };
 
-struct self_t { };
+struct self_t {};
 static const self_t self = self_t();
 
 /// Type for an unused type slot
-struct undefined_t { };
+struct undefined_t {};
 
 /// Don't warn about an unused variable
 inline self_t __self() { return self; }
 
 /// base template of operator implementations
-template <op_id, op_type, typename B, typename L, typename R> struct op_impl { };
+template <op_id, op_type, typename B, typename L, typename R>
+struct op_impl {};
 
 /// Operator implementation generator
-template <op_id id, op_type ot, typename L, typename R> struct op_ {
-    template <typename Class, typename... Extra> void execute(Class &cl, const Extra&... extra) const {
+template <op_id id, op_type ot, typename L, typename R>
+struct op_ {
+    template <typename Class, typename... Extra>
+    void execute(Class &cl, const Extra &...extra) const {
         using Base = typename Class::type;
         using L_type = conditional_t<std::is_same<L, self_t>::value, Base, L>;
         using R_type = conditional_t<std::is_same<R, self_t>::value, Base, R>;
         using op = op_impl<id, ot, Base, L_type, R_type>;
         cl.def(op::name(), &op::execute, is_operator(), extra...);
-        #if PY_MAJOR_VERSION < 3
-        if (PYBIND11_SILENCE_MSVC_C4127(id == op_truediv) ||
-            PYBIND11_SILENCE_MSVC_C4127(id == op_itruediv))
-            cl.def(id == op_itruediv ? "__idiv__" : ot == op_l ? "__div__" : "__rdiv__",
-                    &op::execute, is_operator(), extra...);
-        #endif
+#if PY_MAJOR_VERSION < 3
+        if (PYBIND11_SILENCE_MSVC_C4127(id == op_truediv)
+            || PYBIND11_SILENCE_MSVC_C4127(id == op_itruediv))
+            cl.def(id == op_itruediv ? "__idiv__"
+                   : ot == op_l      ? "__div__"
+                                     : "__rdiv__",
+                   &op::execute,
+                   is_operator(),
+                   extra...);
+#endif
     }
-    template <typename Class, typename... Extra> void execute_cast(Class &cl, const Extra&... extra) const {
+    template <typename Class, typename... Extra>
+    void execute_cast(Class &cl, const Extra &...extra) const {
         using Base = typename Class::type;
         using L_type = conditional_t<std::is_same<L, self_t>::value, Base, L>;
         using R_type = conditional_t<std::is_same<R, self_t>::value, Base, R>;
         using op = op_impl<id, ot, Base, L_type, R_type>;
         cl.def(op::name(), &op::execute_cast, is_operator(), extra...);
-        #if PY_MAJOR_VERSION < 3
+#if PY_MAJOR_VERSION < 3
         if (id == op_truediv || id == op_itruediv)
-            cl.def(id == op_itruediv ? "__idiv__" : ot == op_l ? "__div__" : "__rdiv__",
-                    &op::execute, is_operator(), extra...);
-        #endif
+            cl.def(id == op_itruediv ? "__idiv__"
+                   : ot == op_l      ? "__div__"
+                                     : "__rdiv__",
+                   &op::execute,
+                   is_operator(),
+                   extra...);
+#endif
     }
 };
 
-#define PYBIND11_BINARY_OPERATOR(id, rid, op, expr)                                    \
-template <typename B, typename L, typename R> struct op_impl<op_##id, op_l, B, L, R> { \
-    static char const* name() { return "__" #id "__"; }                                \
-    static auto execute(const L &l, const R &r) -> decltype(expr) { return (expr); }   \
-    static B execute_cast(const L &l, const R &r) { return B(expr); }                  \
-};                                                                                     \
-template <typename B, typename L, typename R> struct op_impl<op_##id, op_r, B, L, R> { \
-    static char const* name() { return "__" #rid "__"; }                               \
-    static auto execute(const R &r, const L &l) -> decltype(expr) { return (expr); }   \
-    static B execute_cast(const R &r, const L &l) { return B(expr); }                  \
-};                                                                                     \
-inline op_<op_##id, op_l, self_t, self_t> op(const self_t &, const self_t &) {         \
-    return op_<op_##id, op_l, self_t, self_t>();                                       \
-}                                                                                      \
-template <typename T> op_<op_##id, op_l, self_t, T> op(const self_t &, const T &) {    \
-    return op_<op_##id, op_l, self_t, T>();                                            \
-}                                                                                      \
-template <typename T> op_<op_##id, op_r, T, self_t> op(const T &, const self_t &) {    \
-    return op_<op_##id, op_r, T, self_t>();                                            \
-}
-
-#define PYBIND11_INPLACE_OPERATOR(id, op, expr)                                        \
-template <typename B, typename L, typename R> struct op_impl<op_##id, op_l, B, L, R> { \
-    static char const* name() { return "__" #id "__"; }                                \
-    static auto execute(L &l, const R &r) -> decltype(expr) { return expr; }           \
-    static B execute_cast(L &l, const R &r) { return B(expr); }                        \
-};                                                                                     \
-template <typename T> op_<op_##id, op_l, self_t, T> op(const self_t &, const T &) {    \
-    return op_<op_##id, op_l, self_t, T>();                                            \
-}
-
-#define PYBIND11_UNARY_OPERATOR(id, op, expr)                                          \
-template <typename B, typename L> struct op_impl<op_##id, op_u, B, L, undefined_t> {   \
-    static char const* name() { return "__" #id "__"; }                                \
-    static auto execute(const L &l) -> decltype(expr) { return expr; }                 \
-    static B execute_cast(const L &l) { return B(expr); }                              \
-};                                                                                     \
-inline op_<op_##id, op_u, self_t, undefined_t> op(const self_t &) {                    \
-    return op_<op_##id, op_u, self_t, undefined_t>();                                  \
-}
-
-PYBIND11_BINARY_OPERATOR(sub,       rsub,         operator-,    l - r)
-PYBIND11_BINARY_OPERATOR(add,       radd,         operator+,    l + r)
-PYBIND11_BINARY_OPERATOR(mul,       rmul,         operator*,    l * r)
-PYBIND11_BINARY_OPERATOR(truediv,   rtruediv,     operator/,    l / r)
-PYBIND11_BINARY_OPERATOR(mod,       rmod,         operator%,    l % r)
-PYBIND11_BINARY_OPERATOR(lshift,    rlshift,      operator<<,   l << r)
-PYBIND11_BINARY_OPERATOR(rshift,    rrshift,      operator>>,   l >> r)
-PYBIND11_BINARY_OPERATOR(and,       rand,         operator&,    l & r)
-PYBIND11_BINARY_OPERATOR(xor,       rxor,         operator^,    l ^ r)
-PYBIND11_BINARY_OPERATOR(eq,        eq,           operator==,   l == r)
-PYBIND11_BINARY_OPERATOR(ne,        ne,           operator!=,   l != r)
-PYBIND11_BINARY_OPERATOR(or,        ror,          operator|,    l | r)
-PYBIND11_BINARY_OPERATOR(gt,        lt,           operator>,    l > r)
-PYBIND11_BINARY_OPERATOR(ge,        le,           operator>=,   l >= r)
-PYBIND11_BINARY_OPERATOR(lt,        gt,           operator<,    l < r)
-PYBIND11_BINARY_OPERATOR(le,        ge,           operator<=,   l <= r)
-//PYBIND11_BINARY_OPERATOR(pow,       rpow,         pow,          std::pow(l,  r))
-PYBIND11_INPLACE_OPERATOR(iadd,     operator+=,   l += r)
-PYBIND11_INPLACE_OPERATOR(isub,     operator-=,   l -= r)
-PYBIND11_INPLACE_OPERATOR(imul,     operator*=,   l *= r)
-PYBIND11_INPLACE_OPERATOR(itruediv, operator/=,   l /= r)
-PYBIND11_INPLACE_OPERATOR(imod,     operator%=,   l %= r)
-PYBIND11_INPLACE_OPERATOR(ilshift,  operator<<=,  l <<= r)
-PYBIND11_INPLACE_OPERATOR(irshift,  operator>>=,  l >>= r)
-PYBIND11_INPLACE_OPERATOR(iand,     operator&=,   l &= r)
-PYBIND11_INPLACE_OPERATOR(ixor,     operator^=,   l ^= r)
-PYBIND11_INPLACE_OPERATOR(ior,      operator|=,   l |= r)
-PYBIND11_UNARY_OPERATOR(neg,        operator-,    -l)
-PYBIND11_UNARY_OPERATOR(pos,        operator+,    +l)
+#define PYBIND11_BINARY_OPERATOR(id, rid, op, expr)                                               \
+    template <typename B, typename L, typename R>                                                 \
+    struct op_impl<op_##id, op_l, B, L, R> {                                                      \
+        static char const *name() { return "__" #id "__"; }                                       \
+        static auto execute(const L &l, const R &r) -> decltype(expr) { return (expr); }          \
+        static B execute_cast(const L &l, const R &r) { return B(expr); }                         \
+    };                                                                                            \
+    template <typename B, typename L, typename R>                                                 \
+    struct op_impl<op_##id, op_r, B, L, R> {                                                      \
+        static char const *name() { return "__" #rid "__"; }                                      \
+        static auto execute(const R &r, const L &l) -> decltype(expr) { return (expr); }          \
+        static B execute_cast(const R &r, const L &l) { return B(expr); }                         \
+    };                                                                                            \
+    inline op_<op_##id, op_l, self_t, self_t> op(const self_t &, const self_t &) {                \
+        return op_<op_##id, op_l, self_t, self_t>();                                              \
+    }                                                                                             \
+    template <typename T>                                                                         \
+    op_<op_##id, op_l, self_t, T> op(const self_t &, const T &) {                                 \
+        return op_<op_##id, op_l, self_t, T>();                                                   \
+    }                                                                                             \
+    template <typename T>                                                                         \
+    op_<op_##id, op_r, T, self_t> op(const T &, const self_t &) {                                 \
+        return op_<op_##id, op_r, T, self_t>();                                                   \
+    }
+
+#define PYBIND11_INPLACE_OPERATOR(id, op, expr)                                                   \
+    template <typename B, typename L, typename R>                                                 \
+    struct op_impl<op_##id, op_l, B, L, R> {                                                      \
+        static char const *name() { return "__" #id "__"; }                                       \
+        static auto execute(L &l, const R &r) -> decltype(expr) { return expr; }                  \
+        static B execute_cast(L &l, const R &r) { return B(expr); }                               \
+    };                                                                                            \
+    template <typename T>                                                                         \
+    op_<op_##id, op_l, self_t, T> op(const self_t &, const T &) {                                 \
+        return op_<op_##id, op_l, self_t, T>();                                                   \
+    }
+
+#define PYBIND11_UNARY_OPERATOR(id, op, expr)                                                     \
+    template <typename B, typename L>                                                             \
+    struct op_impl<op_##id, op_u, B, L, undefined_t> {                                            \
+        static char const *name() { return "__" #id "__"; }                                       \
+        static auto execute(const L &l) -> decltype(expr) { return expr; }                        \
+        static B execute_cast(const L &l) { return B(expr); }                                     \
+    };                                                                                            \
+    inline op_<op_##id, op_u, self_t, undefined_t> op(const self_t &) {                           \
+        return op_<op_##id, op_u, self_t, undefined_t>();                                         \
+    }
+
+PYBIND11_BINARY_OPERATOR(sub, rsub, operator-, l - r)
+PYBIND11_BINARY_OPERATOR(add, radd, operator+, l + r)
+PYBIND11_BINARY_OPERATOR(mul, rmul, operator*, l *r)
+PYBIND11_BINARY_OPERATOR(truediv, rtruediv, operator/, l / r)
+PYBIND11_BINARY_OPERATOR(mod, rmod, operator%, l % r)
+PYBIND11_BINARY_OPERATOR(lshift, rlshift, operator<<, l << r)
+PYBIND11_BINARY_OPERATOR(rshift, rrshift, operator>>, l >> r)
+PYBIND11_BINARY_OPERATOR(and, rand, operator&, l &r)
+PYBIND11_BINARY_OPERATOR(xor, rxor, operator^, l ^ r)
+PYBIND11_BINARY_OPERATOR(eq, eq, operator==, l == r)
+PYBIND11_BINARY_OPERATOR(ne, ne, operator!=, l != r)
+PYBIND11_BINARY_OPERATOR(or, ror, operator|, l | r)
+PYBIND11_BINARY_OPERATOR(gt, lt, operator>, l > r)
+PYBIND11_BINARY_OPERATOR(ge, le, operator>=, l >= r)
+PYBIND11_BINARY_OPERATOR(lt, gt, operator<, l < r)
+PYBIND11_BINARY_OPERATOR(le, ge, operator<=, l <= r)
+// PYBIND11_BINARY_OPERATOR(pow,       rpow,         pow,          std::pow(l,  r))
+PYBIND11_INPLACE_OPERATOR(iadd, operator+=, l += r)
+PYBIND11_INPLACE_OPERATOR(isub, operator-=, l -= r)
+PYBIND11_INPLACE_OPERATOR(imul, operator*=, l *= r)
+PYBIND11_INPLACE_OPERATOR(itruediv, operator/=, l /= r)
+PYBIND11_INPLACE_OPERATOR(imod, operator%=, l %= r)
+PYBIND11_INPLACE_OPERATOR(ilshift, operator<<=, l <<= r)
+PYBIND11_INPLACE_OPERATOR(irshift, operator>>=, l >>= r)
+PYBIND11_INPLACE_OPERATOR(iand, operator&=, l &= r)
+PYBIND11_INPLACE_OPERATOR(ixor, operator^=, l ^= r)
+PYBIND11_INPLACE_OPERATOR(ior, operator|=, l |= r)
+PYBIND11_UNARY_OPERATOR(neg, operator-, -l)
+PYBIND11_UNARY_OPERATOR(pos, operator+, +l)
 // WARNING: This usage of `abs` should only be done for existing STL overloads.
 // Adding overloads directly in to the `std::` namespace is advised against:
 // https://en.cppreference.com/w/cpp/language/extending_std
-PYBIND11_UNARY_OPERATOR(abs,        abs,          std::abs(l))
-PYBIND11_UNARY_OPERATOR(hash,       hash,         std::hash<L>()(l))
-PYBIND11_UNARY_OPERATOR(invert,     operator~,    (~l))
-PYBIND11_UNARY_OPERATOR(bool,       operator!,    !!l)
-PYBIND11_UNARY_OPERATOR(int,        int_,         (int) l)
-PYBIND11_UNARY_OPERATOR(float,      float_,       (double) l)
+PYBIND11_UNARY_OPERATOR(abs, abs, std::abs(l))
+PYBIND11_UNARY_OPERATOR(hash, hash, std::hash<L>()(l))
+PYBIND11_UNARY_OPERATOR(invert, operator~, (~l))
+PYBIND11_UNARY_OPERATOR(bool, operator!, !!l)
+PYBIND11_UNARY_OPERATOR(int, int_, (int) l)
+PYBIND11_UNARY_OPERATOR(float, float_, (double) l)
 
 #undef PYBIND11_BINARY_OPERATOR
 #undef PYBIND11_INPLACE_OPERATOR
diff --git a/include/pybind11/options.h b/include/pybind11/options.h
index d74db1c68d..1950c52f52 100644
--- a/include/pybind11/options.h
+++ b/include/pybind11/options.h
@@ -15,43 +15,54 @@ PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 
 class options {
 public:
-
     // Default RAII constructor, which leaves settings as they currently are.
     options() : previous_state(global_state()) {}
 
     // Class is non-copyable.
-    options(const options&) = delete;
-    options& operator=(const options&) = delete;
+    options(const options &) = delete;
+    options &operator=(const options &) = delete;
 
     // Destructor, which restores settings that were in effect before.
-    ~options() {
-        global_state() = previous_state;
-    }
+    ~options() { global_state() = previous_state; }
 
     // Setter methods (affect the global state):
 
-    options& disable_user_defined_docstrings() & { global_state().show_user_defined_docstrings = false; return *this; }
+    options &disable_user_defined_docstrings() & {
+        global_state().show_user_defined_docstrings = false;
+        return *this;
+    }
 
-    options& enable_user_defined_docstrings() & { global_state().show_user_defined_docstrings = true; return *this; }
+    options &enable_user_defined_docstrings() & {
+        global_state().show_user_defined_docstrings = true;
+        return *this;
+    }
 
-    options& disable_function_signatures() & { global_state().show_function_signatures = false; return *this; }
+    options &disable_function_signatures() & {
+        global_state().show_function_signatures = false;
+        return *this;
+    }
 
-    options& enable_function_signatures() & { global_state().show_function_signatures = true; return *this; }
+    options &enable_function_signatures() & {
+        global_state().show_function_signatures = true;
+        return *this;
+    }
 
     // Getter methods (return the global state):
 
-    static bool show_user_defined_docstrings() { return global_state().show_user_defined_docstrings; }
+    static bool show_user_defined_docstrings() {
+        return global_state().show_user_defined_docstrings;
+    }
 
     static bool show_function_signatures() { return global_state().show_function_signatures; }
 
     // This type is not meant to be allocated on the heap.
-    void* operator new(size_t) = delete;
+    void *operator new(size_t) = delete;
 
 private:
-
     struct state {
-        bool show_user_defined_docstrings = true;  //< Include user-supplied texts in docstrings.
-        bool show_function_signatures = true;      //< Include auto-generated function signatures in docstrings.
+        bool show_user_defined_docstrings = true; //< Include user-supplied texts in docstrings.
+        bool show_function_signatures
+            = true; //< Include auto-generated function signatures in docstrings.
     };
 
     static state &global_state() {
diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h
index 7aa93bb5aa..ab8c71fca7 100644
--- a/include/pybind11/pybind11.h
+++ b/include/pybind11/pybind11.h
@@ -10,30 +10,29 @@
 
 #pragma once
 
+#include "detail/class.h"
+#include "detail/init.h"
 #include "attr.h"
 #include "gil.h"
 #include "options.h"
-#include "detail/class.h"
-#include "detail/init.h"
 
 #include <cstdlib>
+#include <cstring>
 #include <memory>
 #include <new>
-#include <vector>
 #include <string>
 #include <utility>
-
-#include <cstring>
+#include <vector>
 
 #if defined(__cpp_lib_launder) && !(defined(_MSC_VER) && (_MSC_VER < 1914))
-#  define PYBIND11_STD_LAUNDER std::launder
-#  define PYBIND11_HAS_STD_LAUNDER 1
+#    define PYBIND11_STD_LAUNDER std::launder
+#    define PYBIND11_HAS_STD_LAUNDER 1
 #else
-#  define PYBIND11_STD_LAUNDER
-#  define PYBIND11_HAS_STD_LAUNDER 0
+#    define PYBIND11_STD_LAUNDER
+#    define PYBIND11_HAS_STD_LAUNDER 0
 #endif
 #if defined(__GNUG__) && !defined(__clang__)
-#  include <cxxabi.h>
+#    include <cxxabi.h>
 #endif
 
 /* https://stackoverflow.com/questions/46798456/handling-gccs-noexcept-type-warning
@@ -56,7 +55,7 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 // Return true if one of the translators completed without raising an exception
 // itself. Return of false indicates that if there are other translators
 // available, they should be tried.
-inline bool apply_exception_translators(std::forward_list<ExceptionTranslator>& translators) {
+inline bool apply_exception_translators(std::forward_list<ExceptionTranslator> &translators) {
     auto last_exception = std::current_exception();
 
     for (auto &translator : translators) {
@@ -83,30 +82,33 @@ class cpp_function : public function {
 public:
     cpp_function() = default;
     // NOLINTNEXTLINE(google-explicit-constructor)
-    cpp_function(std::nullptr_t) { }
+    cpp_function(std::nullptr_t) {}
 
     /// Construct a cpp_function from a vanilla function pointer
     template <typename Return, typename... Args, typename... Extra>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    cpp_function(Return (*f)(Args...), const Extra&... extra) {
+    cpp_function(Return (*f)(Args...), const Extra &...extra) {
         initialize(f, f, extra...);
     }
 
     /// Construct a cpp_function from a lambda function (possibly with internal state)
-    template <typename Func, typename... Extra,
+    template <typename Func,
+              typename... Extra,
               typename = detail::enable_if_t<detail::is_lambda<Func>::value>>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    cpp_function(Func &&f, const Extra&... extra) {
-        initialize(std::forward<Func>(f),
-                   (detail::function_signature_t<Func> *) nullptr, extra...);
+    cpp_function(Func &&f, const Extra &...extra) {
+        initialize(
+            std::forward<Func>(f), (detail::function_signature_t<Func> *) nullptr, extra...);
     }
 
     /// Construct a cpp_function from a class method (non-const, no ref-qualifier)
     template <typename Return, typename Class, typename... Arg, typename... Extra>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    cpp_function(Return (Class::*f)(Arg...), const Extra&... extra) {
-        initialize([f](Class *c, Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
-                   (Return (*) (Class *, Arg...)) nullptr, extra...);
+    cpp_function(Return (Class::*f)(Arg...), const Extra &...extra) {
+        initialize(
+            [f](Class *c, Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
+            (Return(*)(Class *, Arg...)) nullptr,
+            extra...);
     }
 
     /// Construct a cpp_function from a class method (non-const, lvalue ref-qualifier)
@@ -114,17 +116,21 @@ class cpp_function : public function {
     /// but with an added `&`.
     template <typename Return, typename Class, typename... Arg, typename... Extra>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    cpp_function(Return (Class::*f)(Arg...)&, const Extra&... extra) {
-        initialize([f](Class *c, Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
-                   (Return (*) (Class *, Arg...)) nullptr, extra...);
+    cpp_function(Return (Class::*f)(Arg...) &, const Extra &...extra) {
+        initialize(
+            [f](Class *c, Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
+            (Return(*)(Class *, Arg...)) nullptr,
+            extra...);
     }
 
     /// Construct a cpp_function from a class method (const, no ref-qualifier)
     template <typename Return, typename Class, typename... Arg, typename... Extra>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    cpp_function(Return (Class::*f)(Arg...) const, const Extra&... extra) {
-        initialize([f](const Class *c, Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
-                   (Return (*)(const Class *, Arg ...)) nullptr, extra...);
+    cpp_function(Return (Class::*f)(Arg...) const, const Extra &...extra) {
+        initialize([f](const Class *c,
+                       Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
+                   (Return(*)(const Class *, Arg...)) nullptr,
+                   extra...);
     }
 
     /// Construct a cpp_function from a class method (const, lvalue ref-qualifier)
@@ -132,9 +138,11 @@ class cpp_function : public function {
     /// but with an added `&`.
     template <typename Return, typename Class, typename... Arg, typename... Extra>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    cpp_function(Return (Class::*f)(Arg...) const&, const Extra&... extra) {
-        initialize([f](const Class *c, Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
-                   (Return (*)(const Class *, Arg ...)) nullptr, extra...);
+    cpp_function(Return (Class::*f)(Arg...) const &, const Extra &...extra) {
+        initialize([f](const Class *c,
+                       Arg... args) -> Return { return (c->*f)(std::forward<Arg>(args)...); },
+                   (Return(*)(const Class *, Arg...)) nullptr,
+                   extra...);
     }
 
     /// Return the function name
@@ -144,9 +152,10 @@ class cpp_function : public function {
     struct InitializingFunctionRecordDeleter {
         // `destruct(function_record, false)`: `initialize_generic` copies strings and
         // takes care of cleaning up in case of exceptions. So pass `false` to `free_strings`.
-        void operator()(detail::function_record * rec) { destruct(rec, false); }
+        void operator()(detail::function_record *rec) { destruct(rec, false); }
     };
-    using unique_function_record = std::unique_ptr<detail::function_record, InitializingFunctionRecordDeleter>;
+    using unique_function_record
+        = std::unique_ptr<detail::function_record, InitializingFunctionRecordDeleter>;
 
     /// Space optimization: don't inline this frequently instantiated fragment
     PYBIND11_NOINLINE unique_function_record make_function_record() {
@@ -155,14 +164,17 @@ class cpp_function : public function {
 
     /// Special internal constructor for functors, lambda functions, etc.
     template <typename Func, typename Return, typename... Args, typename... Extra>
-    void initialize(Func &&f, Return (*)(Args...), const Extra&... extra) {
+    void initialize(Func &&f, Return (*)(Args...), const Extra &...extra) {
         using namespace detail;
-        struct capture { remove_reference_t<Func> f; };
+        struct capture {
+            remove_reference_t<Func> f;
+        };
 
-        /* Store the function including any extra state it might have (e.g. a lambda capture object) */
+        /* Store the function including any extra state it might have (e.g. a lambda capture
+         * object) */
         // The unique_ptr makes sure nothing is leaked in case of an exception.
         auto unique_rec = make_function_record();
-        auto rec = unique_rec.get();
+        auto *rec = unique_rec.get();
 
         /* Store the capture object directly in the function record if there is enough space */
         if (PYBIND11_SILENCE_MSVC_C4127(sizeof(capture) <= sizeof(rec->data))) {
@@ -170,16 +182,16 @@ class cpp_function : public function {
                enough space to use the placement new operator. However, the
                'if' statement above ensures that this is the case. */
 #if defined(__GNUG__) && __GNUC__ >= 6 && !defined(__clang__) && !defined(__INTEL_COMPILER)
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wplacement-new"
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wplacement-new"
 #endif
-            new ((capture *) &rec->data) capture { std::forward<Func>(f) };
+            new ((capture *) &rec->data) capture{std::forward<Func>(f)};
 #if defined(__GNUG__) && __GNUC__ >= 6 && !defined(__clang__) && !defined(__INTEL_COMPILER)
-#  pragma GCC diagnostic pop
+#    pragma GCC diagnostic pop
 #endif
 #if defined(__GNUG__) && !PYBIND11_HAS_STD_LAUNDER && !defined(__INTEL_COMPILER)
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wstrict-aliasing"
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wstrict-aliasing"
 #endif
             // UB without std::launder, but without breaking ABI and/or
             // a significant refactoring it's "impossible" to solve.
@@ -190,21 +202,22 @@ class cpp_function : public function {
                     data->~capture();
                 };
 #if defined(__GNUG__) && !PYBIND11_HAS_STD_LAUNDER && !defined(__INTEL_COMPILER)
-#  pragma GCC diagnostic pop
+#    pragma GCC diagnostic pop
 #endif
         } else {
-            rec->data[0] = new capture { std::forward<Func>(f) };
+            rec->data[0] = new capture{std::forward<Func>(f)};
             rec->free_data = [](function_record *r) { delete ((capture *) r->data[0]); };
         }
 
         /* Type casters for the function arguments and return value */
         using cast_in = argument_loader<Args...>;
-        using cast_out = make_caster<
-            conditional_t<std::is_void<Return>::value, void_type, Return>
-        >;
+        using cast_out
+            = make_caster<conditional_t<std::is_void<Return>::value, void_type, Return>>;
 
-        static_assert(expected_num_args<Extra...>(sizeof...(Args), cast_in::args_pos >= 0, cast_in::has_kwargs),
-                      "The number of argument annotations does not match the number of function arguments");
+        static_assert(
+            expected_num_args<Extra...>(
+                sizeof...(Args), cast_in::args_pos >= 0, cast_in::has_kwargs),
+            "The number of argument annotations does not match the number of function arguments");
 
         /* Dispatch code which converts function arguments and performs the actual function call */
         rec->impl = [](function_call &call) -> handle {
@@ -218,19 +231,22 @@ class cpp_function : public function {
             process_attributes<Extra...>::precall(call);
 
             /* Get a pointer to the capture object */
-            auto data = (sizeof(capture) <= sizeof(call.func.data)
-                         ? &call.func.data : call.func.data[0]);
+            const auto *data = (sizeof(capture) <= sizeof(call.func.data) ? &call.func.data
+                                                                          : call.func.data[0]);
             auto *cap = const_cast<capture *>(reinterpret_cast<const capture *>(data));
 
             /* Override policy for rvalues -- usually to enforce rvp::move on an rvalue */
-            return_value_policy policy = return_value_policy_override<Return>::policy(call.func.policy);
+            return_value_policy policy
+                = return_value_policy_override<Return>::policy(call.func.policy);
 
             /* Function scope guard -- defaults to the compile-to-nothing `void_type` */
             using Guard = extract_guard_t<Extra...>;
 
             /* Perform the function call */
-            handle result = cast_out::cast(
-                std::move(args_converter).template call<Return, Guard>(cap->f), policy, call.parent);
+            handle result
+                = cast_out::cast(std::move(args_converter).template call<Return, Guard>(cap->f),
+                                 policy,
+                                 call.parent);
 
             /* Invoke call policy post-call hook */
             process_attributes<Extra...>::postcall(call, result);
@@ -238,9 +254,11 @@ class cpp_function : public function {
             return result;
         };
 
-        rec->nargs_pos = cast_in::args_pos >= 0
-            ? static_cast<std::uint16_t>(cast_in::args_pos)
-            : sizeof...(Args) - cast_in::has_kwargs; // Will get reduced more if we have a kw_only
+        rec->nargs_pos
+            = cast_in::args_pos >= 0
+                  ? static_cast<std::uint16_t>(cast_in::args_pos)
+                  : sizeof...(Args)
+                        - cast_in::has_kwargs; // Will get reduced more if we have a kw_only
         rec->has_args = cast_in::args_pos >= 0;
         rec->has_kwargs = cast_in::has_kwargs;
 
@@ -251,18 +269,26 @@ class cpp_function : public function {
             constexpr bool has_kw_only_args = any_of<std::is_same<kw_only, Extra>...>::value,
                            has_pos_only_args = any_of<std::is_same<pos_only, Extra>...>::value,
                            has_arg_annotations = any_of<is_keyword<Extra>...>::value;
-            static_assert(has_arg_annotations || !has_kw_only_args, "py::kw_only requires the use of argument annotations");
-            static_assert(has_arg_annotations || !has_pos_only_args, "py::pos_only requires the use of argument annotations (for docstrings and aligning the annotations to the argument)");
-
-            static_assert(constexpr_sum(is_kw_only<Extra>::value...) <= 1, "py::kw_only may be specified only once");
-            static_assert(constexpr_sum(is_pos_only<Extra>::value...) <= 1, "py::pos_only may be specified only once");
+            static_assert(has_arg_annotations || !has_kw_only_args,
+                          "py::kw_only requires the use of argument annotations");
+            static_assert(has_arg_annotations || !has_pos_only_args,
+                          "py::pos_only requires the use of argument annotations (for docstrings "
+                          "and aligning the annotations to the argument)");
+
+            static_assert(constexpr_sum(is_kw_only<Extra>::value...) <= 1,
+                          "py::kw_only may be specified only once");
+            static_assert(constexpr_sum(is_pos_only<Extra>::value...) <= 1,
+                          "py::pos_only may be specified only once");
             constexpr auto kw_only_pos = constexpr_first<is_kw_only, Extra...>();
             constexpr auto pos_only_pos = constexpr_first<is_pos_only, Extra...>();
-            static_assert(!(has_kw_only_args && has_pos_only_args) || pos_only_pos < kw_only_pos, "py::pos_only must come before py::kw_only");
+            static_assert(!(has_kw_only_args && has_pos_only_args) || pos_only_pos < kw_only_pos,
+                          "py::pos_only must come before py::kw_only");
         }
 
-        /* Generate a readable signature describing the function's arguments and return value types */
-        static constexpr auto signature = const_name("(") + cast_in::arg_names + const_name(") -> ") + cast_out::name;
+        /* Generate a readable signature describing the function's arguments and return value types
+         */
+        static constexpr auto signature
+            = const_name("(") + cast_in::arg_names + const_name(") -> ") + cast_out::name;
         PYBIND11_DESCR_CONSTEXPR auto types = decltype(signature)::types();
 
         /* Register the function with Python from generic (non-templated) code */
@@ -271,54 +297,59 @@ class cpp_function : public function {
 
         /* Stash some additional information used by an important optimization in 'functional.h' */
         using FunctionType = Return (*)(Args...);
-        constexpr bool is_function_ptr =
-            std::is_convertible<Func, FunctionType>::value &&
-            sizeof(capture) == sizeof(void *);
+        constexpr bool is_function_ptr
+            = std::is_convertible<Func, FunctionType>::value && sizeof(capture) == sizeof(void *);
         if (is_function_ptr) {
             rec->is_stateless = true;
-            rec->data[1] = const_cast<void *>(reinterpret_cast<const void *>(&typeid(FunctionType)));
+            rec->data[1]
+                = const_cast<void *>(reinterpret_cast<const void *>(&typeid(FunctionType)));
         }
     }
 
-    // Utility class that keeps track of all duplicated strings, and cleans them up in its destructor,
-    // unless they are released. Basically a RAII-solution to deal with exceptions along the way.
+    // Utility class that keeps track of all duplicated strings, and cleans them up in its
+    // destructor, unless they are released. Basically a RAII-solution to deal with exceptions
+    // along the way.
     class strdup_guard {
     public:
         ~strdup_guard() {
-            for (auto s : strings)
+            for (auto *s : strings)
                 std::free(s);
         }
         char *operator()(const char *s) {
-            auto t = PYBIND11_COMPAT_STRDUP(s);
+            auto *t = PYBIND11_COMPAT_STRDUP(s);
             strings.push_back(t);
             return t;
         }
-        void release() {
-            strings.clear();
-        }
+        void release() { strings.clear(); }
+
     private:
         std::vector<char *> strings;
     };
 
     /// Register a function call with Python (generic non-templated code goes here)
-    void initialize_generic(unique_function_record &&unique_rec, const char *text,
-                            const std::type_info *const *types, size_t args) {
+    void initialize_generic(unique_function_record &&unique_rec,
+                            const char *text,
+                            const std::type_info *const *types,
+                            size_t args) {
         // Do NOT receive `unique_rec` by value. If this function fails to move out the unique_ptr,
-        // we do not want this to destuct the pointer. `initialize` (the caller) still relies on the
-        // pointee being alive after this call. Only move out if a `capsule` is going to keep it alive.
-        auto rec = unique_rec.get();
+        // we do not want this to destuct the pointer. `initialize` (the caller) still relies on
+        // the pointee being alive after this call. Only move out if a `capsule` is going to keep
+        // it alive.
+        auto *rec = unique_rec.get();
 
         // Keep track of strdup'ed strings, and clean them up as long as the function's capsule
         // has not taken ownership yet (when `unique_rec.release()` is called).
-        // Note: This cannot easily be fixed by a `unique_ptr` with custom deleter, because the strings
-        // are only referenced before strdup'ing. So only *after* the following block could `destruct`
-        // safely be called, but even then, `repr` could still throw in the middle of copying all strings.
+        // Note: This cannot easily be fixed by a `unique_ptr` with custom deleter, because the
+        // strings are only referenced before strdup'ing. So only *after* the following block could
+        // `destruct` safely be called, but even then, `repr` could still throw in the middle of
+        // copying all strings.
         strdup_guard guarded_strdup;
 
         /* Create copies of all referenced C-style strings */
         rec->name = guarded_strdup(rec->name ? rec->name : "");
-        if (rec->doc) rec->doc = guarded_strdup(rec->doc);
-        for (auto &a: rec->args) {
+        if (rec->doc)
+            rec->doc = guarded_strdup(rec->doc);
+        for (auto &a : rec->args) {
             if (a.name)
                 a.name = guarded_strdup(a.name);
             if (a.descr)
@@ -332,15 +363,19 @@ class cpp_function : public function {
 
 #if !defined(NDEBUG) && !defined(PYBIND11_DISABLE_NEW_STYLE_INIT_WARNING)
         if (rec->is_constructor && !rec->is_new_style_constructor) {
-            const auto class_name = detail::get_fully_qualified_tp_name((PyTypeObject *) rec->scope.ptr());
+            const auto class_name
+                = detail::get_fully_qualified_tp_name((PyTypeObject *) rec->scope.ptr());
             const auto func_name = std::string(rec->name);
-            PyErr_WarnEx(
-                PyExc_FutureWarning,
-                ("pybind11-bound class '" + class_name + "' is using an old-style "
-                 "placement-new '" + func_name + "' which has been deprecated. See "
-                 "the upgrade guide in pybind11's docs. This message is only visible "
-                 "when compiled in debug mode.").c_str(), 0
-            );
+            PyErr_WarnEx(PyExc_FutureWarning,
+                         ("pybind11-bound class '" + class_name
+                          + "' is using an old-style "
+                            "placement-new '"
+                          + func_name
+                          + "' which has been deprecated. See "
+                            "the upgrade guide in pybind11's docs. This message is only visible "
+                            "when compiled in debug mode.")
+                             .c_str(),
+                         0);
         }
 #endif
 
@@ -348,7 +383,7 @@ class cpp_function : public function {
         std::string signature;
         size_t type_index = 0, arg_index = 0;
         bool is_starred = false;
-        for (auto *pc = text; *pc != '\0'; ++pc) {
+        for (const auto *pc = text; *pc != '\0'; ++pc) {
             const auto c = *pc;
 
             if (c == '{') {
@@ -384,17 +419,17 @@ class cpp_function : public function {
                 const std::type_info *t = types[type_index++];
                 if (!t)
                     pybind11_fail("Internal error while parsing type signature (1)");
-                if (auto tinfo = detail::get_type_info(*t)) {
+                if (auto *tinfo = detail::get_type_info(*t)) {
                     handle th((PyObject *) tinfo->type);
-                    signature +=
-                        th.attr("__module__").cast<std::string>() + "." +
-                        th.attr("__qualname__").cast<std::string>(); // Python 3.3+, but we backport it to earlier versions
+                    signature += th.attr("__module__").cast<std::string>() + "."
+                                 + th.attr("__qualname__")
+                                       .cast<std::string>(); // Python 3.3+, but we backport it to
+                                                             // earlier versions
                 } else if (rec->is_new_style_constructor && arg_index == 0) {
                     // A new-style `__init__` takes `self` as `value_and_holder`.
                     // Rewrite it to the proper class type.
-                    signature +=
-                        rec->scope.attr("__module__").cast<std::string>() + "." +
-                        rec->scope.attr("__qualname__").cast<std::string>();
+                    signature += rec->scope.attr("__module__").cast<std::string>() + "."
+                                 + rec->scope.attr("__qualname__").cast<std::string>();
                 } else {
                     std::string tname(t->name());
                     detail::clean_type_id(tname);
@@ -428,17 +463,19 @@ class cpp_function : public function {
         if (rec->sibling) {
             if (PyCFunction_Check(rec->sibling.ptr())) {
                 auto *self = PyCFunction_GET_SELF(rec->sibling.ptr());
-                capsule rec_capsule = isinstance<capsule>(self) ? reinterpret_borrow<capsule>(self) : capsule(self);
+                capsule rec_capsule = isinstance<capsule>(self) ? reinterpret_borrow<capsule>(self)
+                                                                : capsule(self);
                 chain = (detail::function_record *) rec_capsule;
                 /* Never append a method to an overload chain of a parent class;
                    instead, hide the parent's overloads in this case */
                 if (!chain->scope.is(rec->scope))
                     chain = nullptr;
             }
-            // Don't trigger for things like the default __init__, which are wrapper_descriptors that we are intentionally replacing
+            // Don't trigger for things like the default __init__, which are wrapper_descriptors
+            // that we are intentionally replacing
             else if (!rec->sibling.is_none() && rec->name[0] != '_')
-                pybind11_fail("Cannot overload existing non-function object \"" + std::string(rec->name) +
-                        "\" with a function of the same name");
+                pybind11_fail("Cannot overload existing non-function object \""
+                              + std::string(rec->name) + "\" with a function of the same name");
         }
 
         if (!chain) {
@@ -450,9 +487,8 @@ class cpp_function : public function {
                 = reinterpret_cast<PyCFunction>(reinterpret_cast<void (*)()>(dispatcher));
             rec->def->ml_flags = METH_VARARGS | METH_KEYWORDS;
 
-            capsule rec_capsule(unique_rec.release(), [](void *ptr) {
-                destruct((detail::function_record *) ptr);
-            });
+            capsule rec_capsule(unique_rec.release(),
+                                [](void *ptr) { destruct((detail::function_record *) ptr); });
             guarded_strdup.release();
 
             object scope_module;
@@ -472,13 +508,16 @@ class cpp_function : public function {
             m_ptr = rec->sibling.ptr();
             inc_ref();
             if (chain->is_method != rec->is_method)
-                pybind11_fail("overloading a method with both static and instance methods is not supported; "
-                    #if defined(NDEBUG)
-                        "compile in debug mode for more details"
-                    #else
-                        "error while attempting to bind " + std::string(rec->is_method ? "instance" : "static") + " method " +
-                        std::string(pybind11::str(rec->scope.attr("__name__"))) + "." + std::string(rec->name) + signature
-                    #endif
+                pybind11_fail(
+                    "overloading a method with both static and instance methods is not supported; "
+#if defined(NDEBUG)
+                    "compile in debug mode for more details"
+#else
+                    "error while attempting to bind "
+                    + std::string(rec->is_method ? "instance" : "static") + " method "
+                    + std::string(pybind11::str(rec->scope.attr("__name__"))) + "."
+                    + std::string(rec->name) + signature
+#endif
                 );
 
             if (rec->prepend) {
@@ -487,7 +526,8 @@ class cpp_function : public function {
                 // chain.
                 chain_start = rec;
                 rec->next = chain;
-                auto rec_capsule = reinterpret_borrow<capsule>(((PyCFunctionObject *) m_ptr)->m_self);
+                auto rec_capsule
+                    = reinterpret_borrow<capsule>(((PyCFunctionObject *) m_ptr)->m_self);
                 rec_capsule.set_pointer(unique_rec.release());
                 guarded_strdup.release();
             } else {
@@ -512,9 +552,10 @@ class cpp_function : public function {
         }
         // Then specific overload signatures
         bool first_user_def = true;
-        for (auto it = chain_start; it != nullptr; it = it->next) {
+        for (auto *it = chain_start; it != nullptr; it = it->next) {
             if (options::show_function_signatures()) {
-                if (index > 0) signatures += "\n";
+                if (index > 0)
+                    signatures += "\n";
                 if (chain)
                     signatures += std::to_string(++index) + ". ";
                 signatures += rec->name;
@@ -522,15 +563,19 @@ class cpp_function : public function {
                 signatures += "\n";
             }
             if (it->doc && it->doc[0] != '\0' && options::show_user_defined_docstrings()) {
-                // If we're appending another docstring, and aren't printing function signatures, we
-                // need to append a newline first:
+                // If we're appending another docstring, and aren't printing function signatures,
+                // we need to append a newline first:
                 if (!options::show_function_signatures()) {
-                    if (first_user_def) first_user_def = false;
-                    else signatures += "\n";
+                    if (first_user_def)
+                        first_user_def = false;
+                    else
+                        signatures += "\n";
                 }
-                if (options::show_function_signatures()) signatures += "\n";
+                if (options::show_function_signatures())
+                    signatures += "\n";
                 signatures += it->doc;
-                if (options::show_function_signatures()) signatures += "\n";
+                if (options::show_function_signatures())
+                    signatures += "\n";
             }
         }
 
@@ -544,18 +589,19 @@ class cpp_function : public function {
         if (rec->is_method) {
             m_ptr = PYBIND11_INSTANCE_METHOD_NEW(m_ptr, rec->scope.ptr());
             if (!m_ptr)
-                pybind11_fail("cpp_function::cpp_function(): Could not allocate instance method object");
+                pybind11_fail(
+                    "cpp_function::cpp_function(): Could not allocate instance method object");
             Py_DECREF(func);
         }
     }
 
     /// When a cpp_function is GCed, release any memory allocated by pybind11
     static void destruct(detail::function_record *rec, bool free_strings = true) {
-        // If on Python 3.9, check the interpreter "MICRO" (patch) version.
-        // If this is running on 3.9.0, we have to work around a bug.
-        #if !defined(PYPY_VERSION) && PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION == 9
-            static bool is_zero = Py_GetVersion()[4] == '0';
-        #endif
+// If on Python 3.9, check the interpreter "MICRO" (patch) version.
+// If this is running on 3.9.0, we have to work around a bug.
+#if !defined(PYPY_VERSION) && PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION == 9
+        static bool is_zero = Py_GetVersion()[4] == '0';
+#endif
 
         while (rec) {
             detail::function_record *next = rec->next;
@@ -568,31 +614,30 @@ class cpp_function : public function {
                 std::free((char *) rec->name);
                 std::free((char *) rec->doc);
                 std::free((char *) rec->signature);
-                for (auto &arg: rec->args) {
+                for (auto &arg : rec->args) {
                     std::free(const_cast<char *>(arg.name));
                     std::free(const_cast<char *>(arg.descr));
                 }
             }
-            for (auto &arg: rec->args)
+            for (auto &arg : rec->args)
                 arg.value.dec_ref();
             if (rec->def) {
                 std::free(const_cast<char *>(rec->def->ml_doc));
-                // Python 3.9.0 decref's these in the wrong order; rec->def
-                // If loaded on 3.9.0, let these leak (use Python 3.9.1 at runtime to fix)
-                // See https://github.com/python/cpython/pull/22670
-                #if !defined(PYPY_VERSION) && PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION == 9
-                    if (!is_zero)
-                        delete rec->def;
-                #else
+// Python 3.9.0 decref's these in the wrong order; rec->def
+// If loaded on 3.9.0, let these leak (use Python 3.9.1 at runtime to fix)
+// See https://github.com/python/cpython/pull/22670
+#if !defined(PYPY_VERSION) && PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION == 9
+                if (!is_zero)
                     delete rec->def;
-                #endif
+#else
+                delete rec->def;
+#endif
             }
             delete rec;
             rec = next;
         }
     }
 
-
     /// Main dispatch logic for calls to functions bound using pybind11
     static PyObject *dispatcher(PyObject *self, PyObject *args_in, PyObject *kwargs_in) {
         using namespace detail;
@@ -601,7 +646,8 @@ class cpp_function : public function {
         const function_record *overloads = (function_record *) PyCapsule_GetPointer(self, nullptr),
                               *it = overloads;
 
-        /* Need to know how many arguments + keyword arguments there are to pick the right overload */
+        /* Need to know how many arguments + keyword arguments there are to pick the right overload
+         */
         const auto n_args_in = (size_t) PyTuple_GET_SIZE(args_in);
 
         handle parent = n_args_in > 0 ? PyTuple_GET_ITEM(args_in, 0) : nullptr,
@@ -609,13 +655,16 @@ class cpp_function : public function {
 
         auto self_value_and_holder = value_and_holder();
         if (overloads->is_constructor) {
-            if (!parent || !PyObject_TypeCheck(parent.ptr(), (PyTypeObject *) overloads->scope.ptr())) {
-                PyErr_SetString(PyExc_TypeError, "__init__(self, ...) called with invalid or missing `self` argument");
+            if (!parent
+                || !PyObject_TypeCheck(parent.ptr(), (PyTypeObject *) overloads->scope.ptr())) {
+                PyErr_SetString(
+                    PyExc_TypeError,
+                    "__init__(self, ...) called with invalid or missing `self` argument");
                 return nullptr;
             }
 
-            const auto tinfo = get_type_info((PyTypeObject *) overloads->scope.ptr());
-            const auto pi = reinterpret_cast<instance *>(parent.ptr());
+            auto *const tinfo = get_type_info((PyTypeObject *) overloads->scope.ptr());
+            auto *const pi = reinterpret_cast<instance *>(parent.ptr());
             self_value_and_holder = pi->get_value_and_holder(tinfo, true);
 
             // If this value is already registered it must mean __init__ is invoked multiple times;
@@ -640,36 +689,40 @@ class cpp_function : public function {
                    1. Copy all positional arguments we were given, also checking to make sure that
                       named positional arguments weren't *also* specified via kwarg.
                    2. If we weren't given enough, try to make up the omitted ones by checking
-                      whether they were provided by a kwarg matching the `py::arg("name")` name.  If
+                      whether they were provided by a kwarg matching the `py::arg("name")` name. If
                       so, use it (and remove it from kwargs); if not, see if the function binding
                       provided a default that we can use.
-                   3. Ensure that either all keyword arguments were "consumed", or that the function
-                      takes a kwargs argument to accept unconsumed kwargs.
+                   3. Ensure that either all keyword arguments were "consumed", or that the
+                   function takes a kwargs argument to accept unconsumed kwargs.
                    4. Any positional arguments still left get put into a tuple (for args), and any
                       leftover kwargs get put into a dict.
                    5. Pack everything into a vector; if we have py::args or py::kwargs, they are an
                       extra tuple or dict at the end of the positional arguments.
                    6. Call the function call dispatcher (function_record::impl)
 
-                   If one of these fail, move on to the next overload and keep trying until we get a
-                   result other than PYBIND11_TRY_NEXT_OVERLOAD.
+                   If one of these fail, move on to the next overload and keep trying until we get
+                   a result other than PYBIND11_TRY_NEXT_OVERLOAD.
                  */
 
                 const function_record &func = *it;
-                size_t num_args = func.nargs;    // Number of positional arguments that we need
-                if (func.has_args) --num_args;   // (but don't count py::args
-                if (func.has_kwargs) --num_args; //  or py::kwargs)
+                size_t num_args = func.nargs; // Number of positional arguments that we need
+                if (func.has_args)
+                    --num_args; // (but don't count py::args
+                if (func.has_kwargs)
+                    --num_args; //  or py::kwargs)
                 size_t pos_args = func.nargs_pos;
 
                 if (!func.has_args && n_args_in > pos_args)
                     continue; // Too many positional arguments for this overload
 
                 if (n_args_in < pos_args && func.args.size() < pos_args)
-                    continue; // Not enough positional arguments given, and not enough defaults to fill in the blanks
+                    continue; // Not enough positional arguments given, and not enough defaults to
+                              // fill in the blanks
 
                 function_call call(func, parent);
 
-                size_t args_to_copy = (std::min)(pos_args, n_args_in); // Protect std::min with parentheses
+                size_t args_to_copy
+                    = (std::min)(pos_args, n_args_in); // Protect std::min with parentheses
                 size_t args_copied = 0;
 
                 // 0. Inject new-style `self` argument
@@ -688,8 +741,10 @@ class cpp_function : public function {
                 // 1. Copy any position arguments given.
                 bool bad_arg = false;
                 for (; args_copied < args_to_copy; ++args_copied) {
-                    const argument_record *arg_rec = args_copied < func.args.size() ? &func.args[args_copied] : nullptr;
-                    if (kwargs_in && arg_rec && arg_rec->name && dict_getitemstring(kwargs_in, arg_rec->name)) {
+                    const argument_record *arg_rec
+                        = args_copied < func.args.size() ? &func.args[args_copied] : nullptr;
+                    if (kwargs_in && arg_rec && arg_rec->name
+                        && dict_getitemstring(kwargs_in, arg_rec->name)) {
                         bad_arg = true;
                         break;
                     }
@@ -761,19 +816,20 @@ class cpp_function : public function {
                         }
 
                         if (value) {
-                            // If we're at the py::args index then first insert a stub for it to be replaced later
+                            // If we're at the py::args index then first insert a stub for it to be
+                            // replaced later
                             if (func.has_args && call.args.size() == func.nargs_pos)
                                 call.args.push_back(none());
 
                             call.args.push_back(value);
                             call.args_convert.push_back(arg_rec.convert);
-                        }
-                        else
+                        } else
                             break;
                     }
 
                     if (args_copied < num_args)
-                        continue; // Not enough arguments, defaults, or kwargs to fill the positional arguments
+                        continue; // Not enough arguments, defaults, or kwargs to fill the
+                                  // positional arguments
                 }
 
                 // 3. Check everything was consumed (unless we have a kwargs arg)
@@ -813,12 +869,13 @@ class cpp_function : public function {
                     call.kwargs_ref = std::move(kwargs);
                 }
 
-                // 5. Put everything in a vector.  Not technically step 5, we've been building it
-                // in `call.args` all along.
-                #if !defined(NDEBUG)
+// 5. Put everything in a vector.  Not technically step 5, we've been building it
+// in `call.args` all along.
+#if !defined(NDEBUG)
                 if (call.args.size() != func.nargs || call.args_convert.size() != func.nargs)
-                    pybind11_fail("Internal error: function call dispatcher inserted wrong number of arguments!");
-                #endif
+                    pybind11_fail("Internal error: function call dispatcher inserted wrong number "
+                                  "of arguments!");
+#endif
 
                 std::vector<bool> second_pass_convert;
                 if (overloaded) {
@@ -857,7 +914,8 @@ class cpp_function : public function {
             }
 
             if (overloaded && !second_pass.empty() && result.ptr() == PYBIND11_TRY_NEXT_OVERLOAD) {
-                // The no-conversion pass finished without success, try again with conversion allowed
+                // The no-conversion pass finished without success, try again with conversion
+                // allowed
                 for (auto &call : second_pass) {
                     try {
                         loader_life_support guard{};
@@ -879,7 +937,7 @@ class cpp_function : public function {
             e.restore();
             return nullptr;
 #ifdef __GLIBCXX__
-        } catch ( abi::__forced_unwind& ) {
+        } catch (abi::__forced_unwind &) {
             throw;
 #endif
         } catch (...) {
@@ -896,9 +954,11 @@ class cpp_function : public function {
                 - catch the exception and call PyErr_SetString or PyErr_SetObject
                   to set a standard (or custom) Python exception, or
                 - do nothing and let the exception fall through to the next translator, or
-                - delegate translation to the next translator by throwing a new type of exception. */
+                - delegate translation to the next translator by throwing a new type of exception.
+             */
 
-            auto &local_exception_translators = get_local_internals().registered_exception_translators;
+            auto &local_exception_translators
+                = get_local_internals().registered_exception_translators;
             if (detail::apply_exception_translators(local_exception_translators)) {
                 return nullptr;
             }
@@ -907,7 +967,8 @@ class cpp_function : public function {
                 return nullptr;
             }
 
-            PyErr_SetString(PyExc_SystemError, "Exception escaped from default exception translator!");
+            PyErr_SetString(PyExc_SystemError,
+                            "Exception escaped from default exception translator!");
             return nullptr;
         }
 
@@ -925,17 +986,18 @@ class cpp_function : public function {
             if (overloads->is_operator)
                 return handle(Py_NotImplemented).inc_ref().ptr();
 
-            std::string msg = std::string(overloads->name) + "(): incompatible " +
-                std::string(overloads->is_constructor ? "constructor" : "function") +
-                " arguments. The following argument types are supported:\n";
+            std::string msg = std::string(overloads->name) + "(): incompatible "
+                              + std::string(overloads->is_constructor ? "constructor" : "function")
+                              + " arguments. The following argument types are supported:\n";
 
             int ctr = 0;
             for (const function_record *it2 = overloads; it2 != nullptr; it2 = it2->next) {
-                msg += "    "+ std::to_string(++ctr) + ". ";
+                msg += "    " + std::to_string(++ctr) + ". ";
 
                 bool wrote_sig = false;
                 if (overloads->is_constructor) {
-                    // For a constructor, rewrite `(self: Object, arg0, ...) -> NoneType` as `Object(arg0, ...)`
+                    // For a constructor, rewrite `(self: Object, arg0, ...) -> NoneType` as
+                    // `Object(arg0, ...)`
                     std::string sig = it2->signature;
                     size_t start = sig.find('(') + 7; // skip "(self: "
                     if (start < sig.size()) {
@@ -943,7 +1005,8 @@ class cpp_function : public function {
                         size_t end = sig.find(", "), next = end + 2;
                         size_t ret = sig.rfind(" -> ");
                         // Or the ), if there is no comma:
-                        if (end >= sig.size()) next = end = sig.find(')');
+                        if (end >= sig.size())
+                            next = end = sig.find(')');
                         if (start < end && next < sig.size()) {
                             msg.append(sig, start, end - start);
                             msg += '(';
@@ -952,7 +1015,8 @@ class cpp_function : public function {
                         }
                     }
                 }
-                if (!wrote_sig) msg += it2->signature;
+                if (!wrote_sig)
+                    msg += it2->signature;
 
                 msg += "\n";
             }
@@ -960,27 +1024,32 @@ class cpp_function : public function {
             auto args_ = reinterpret_borrow<tuple>(args_in);
             bool some_args = false;
             for (size_t ti = overloads->is_constructor ? 1 : 0; ti < args_.size(); ++ti) {
-                if (!some_args) some_args = true;
-                else msg += ", ";
+                if (!some_args)
+                    some_args = true;
+                else
+                    msg += ", ";
                 try {
                     msg += pybind11::repr(args_[ti]);
-                } catch (const error_already_set&) {
+                } catch (const error_already_set &) {
                     msg += "<repr raised Error>";
                 }
             }
             if (kwargs_in) {
                 auto kwargs = reinterpret_borrow<dict>(kwargs_in);
                 if (!kwargs.empty()) {
-                    if (some_args) msg += "; ";
+                    if (some_args)
+                        msg += "; ";
                     msg += "kwargs: ";
                     bool first = true;
                     for (auto kwarg : kwargs) {
-                        if (first) first = false;
-                        else msg += ", ";
+                        if (first)
+                            first = false;
+                        else
+                            msg += ", ";
                         msg += pybind11::str("{}=").format(kwarg.first);
                         try {
                             msg += pybind11::repr(kwarg.second);
-                        } catch (const error_already_set&) {
+                        } catch (const error_already_set &) {
                             msg += "<repr raised Error>";
                         }
                     }
@@ -1022,7 +1091,6 @@ class cpp_function : public function {
     }
 };
 
-
 /// Wrapper for Python extension modules
 class module_ : public object {
 public:
@@ -1044,11 +1112,15 @@ class module_ : public object {
         details on the ``Extra&& ... extra`` argument, see section :ref:`extras`.
     \endrst */
     template <typename Func, typename... Extra>
-    module_ &def(const char *name_, Func &&f, const Extra& ... extra) {
-        cpp_function func(std::forward<Func>(f), name(name_), scope(*this),
-                          sibling(getattr(*this, name_, none())), extra...);
+    module_ &def(const char *name_, Func &&f, const Extra &...extra) {
+        cpp_function func(std::forward<Func>(f),
+                          name(name_),
+                          scope(*this),
+                          sibling(getattr(*this, name_, none())),
+                          extra...);
         // NB: allow overwriting here because cpp_function sets up a chain with the intention of
-        // overwriting (and has already checked internally that it isn't overwriting non-functions).
+        // overwriting (and has already checked internally that it isn't overwriting
+        // non-functions).
         add_object(name_, func, true /* overwrite */);
         return *this;
     }
@@ -1064,8 +1136,8 @@ class module_ : public object {
             py::module_ m3 = m2.def_submodule("subsub", "A submodule of 'example.sub'");
     \endrst */
     module_ def_submodule(const char *name, const char *doc = nullptr) {
-        std::string full_name = std::string(PyModule_GetName(m_ptr))
-            + std::string(".") + std::string(name);
+        std::string full_name
+            = std::string(PyModule_GetName(m_ptr)) + std::string(".") + std::string(name);
         auto result = reinterpret_borrow<module_>(PyImport_AddModule(full_name.c_str()));
         if (doc && options::show_user_defined_docstrings())
             result.attr("__doc__") = pybind11::str(doc);
@@ -1093,13 +1165,14 @@ class module_ : public object {
         Adds an object to the module using the given name.  Throws if an object with the given name
         already exists.
 
-        ``overwrite`` should almost always be false: attempting to overwrite objects that pybind11 has
-        established will, in most cases, break things.
+        ``overwrite`` should almost always be false: attempting to overwrite objects that pybind11
+        has established will, in most cases, break things.
     \endrst */
     PYBIND11_NOINLINE void add_object(const char *name, handle obj, bool overwrite = false) {
         if (!overwrite && hasattr(*this, name))
-            pybind11_fail("Error during initialization: multiple incompatible definitions with name \"" +
-                    std::string(name) + "\"");
+            pybind11_fail(
+                "Error during initialization: multiple incompatible definitions with name \""
+                + std::string(name) + "\"");
 
         PyModule_AddObject(ptr(), name, obj.inc_ref().ptr() /* steals a reference */);
     }
@@ -1119,29 +1192,31 @@ class module_ : public object {
     static module_ create_extension_module(const char *name, const char *doc, module_def *def) {
 #if PY_MAJOR_VERSION >= 3
         // module_def is PyModuleDef
-        def = new (def) PyModuleDef {  // Placement new (not an allocation).
-            /* m_base */     PyModuleDef_HEAD_INIT,
-            /* m_name */     name,
-            /* m_doc */      options::show_user_defined_docstrings() ? doc : nullptr,
-            /* m_size */     -1,
-            /* m_methods */  nullptr,
-            /* m_slots */    nullptr,
-            /* m_traverse */ nullptr,
-            /* m_clear */    nullptr,
-            /* m_free */     nullptr
-        };
-        auto m = PyModule_Create(def);
+        def = new (def)
+            PyModuleDef{// Placement new (not an allocation).
+                        /* m_base */ PyModuleDef_HEAD_INIT,
+                        /* m_name */ name,
+                        /* m_doc */ options::show_user_defined_docstrings() ? doc : nullptr,
+                        /* m_size */ -1,
+                        /* m_methods */ nullptr,
+                        /* m_slots */ nullptr,
+                        /* m_traverse */ nullptr,
+                        /* m_clear */ nullptr,
+                        /* m_free */ nullptr};
+        auto *m = PyModule_Create(def);
 #else
         // Ignore module_def *def; only necessary for Python 3
         (void) def;
-        auto m = Py_InitModule3(name, nullptr, options::show_user_defined_docstrings() ? doc : nullptr);
+        auto m = Py_InitModule3(
+            name, nullptr, options::show_user_defined_docstrings() ? doc : nullptr);
 #endif
         if (m == nullptr) {
             if (PyErr_Occurred())
                 throw error_already_set();
             pybind11_fail("Internal error in module_::create_extension_module()");
         }
-        // TODO: Should be reinterpret_steal for Python 3, but Python also steals it again when returned from PyInit_...
+        // TODO: Should be reinterpret_steal for Python 3, but Python also steals it again when
+        // returned from PyInit_...
         //       For Python 2, reinterpret_borrow is correct.
         return reinterpret_borrow<module_>(m);
     }
@@ -1161,10 +1236,10 @@ inline dict globals() {
 }
 
 #if PY_VERSION_HEX >= 0x03030000
-template <typename... Args,
-          typename = detail::enable_if_t<args_are_all_keyword_or_ds<Args...>()>>
-PYBIND11_DEPRECATED("make_simple_namespace should be replaced with py::module_::import(\"types\").attr(\"SimpleNamespace\") ")
-object make_simple_namespace(Args&&... args_) {
+template <typename... Args, typename = detail::enable_if_t<args_are_all_keyword_or_ds<Args...>()>>
+PYBIND11_DEPRECATED("make_simple_namespace should be replaced with "
+                    "py::module_::import(\"types\").attr(\"SimpleNamespace\") ")
+object make_simple_namespace(Args &&...args_) {
     return module_::import("types").attr("SimpleNamespace")(std::forward<Args>(args_)...);
 }
 #endif
@@ -1176,14 +1251,15 @@ class generic_type : public object {
     PYBIND11_OBJECT_DEFAULT(generic_type, object, PyType_Check)
 protected:
     void initialize(const type_record &rec) {
-        if (rec.scope && hasattr(rec.scope, "__dict__") && rec.scope.attr("__dict__").contains(rec.name))
-            pybind11_fail("generic_type: cannot initialize type \"" + std::string(rec.name) +
-                          "\": an object with that name is already defined");
+        if (rec.scope && hasattr(rec.scope, "__dict__")
+            && rec.scope.attr("__dict__").contains(rec.name))
+            pybind11_fail("generic_type: cannot initialize type \"" + std::string(rec.name)
+                          + "\": an object with that name is already defined");
 
         if ((rec.module_local ? get_local_type_info(*rec.type) : get_global_type_info(*rec.type))
             != nullptr)
-            pybind11_fail("generic_type: type \"" + std::string(rec.name) +
-                          "\" is already registered!");
+            pybind11_fail("generic_type: type \"" + std::string(rec.name)
+                          + "\" is already registered!");
 
         m_ptr = make_new_python_type(rec);
 
@@ -1209,13 +1285,12 @@ class generic_type : public object {
             get_local_internals().registered_types_cpp[tindex] = tinfo;
         else
             internals.registered_types_cpp[tindex] = tinfo;
-        internals.registered_types_py[(PyTypeObject *) m_ptr] = { tinfo };
+        internals.registered_types_py[(PyTypeObject *) m_ptr] = {tinfo};
 
         if (rec.bases.size() > 1 || rec.multiple_inheritance) {
             mark_parents_nonsimple(tinfo->type);
             tinfo->simple_ancestors = false;
-        }
-        else if (rec.bases.size() == 1) {
+        } else if (rec.bases.size() == 1) {
             auto *parent_tinfo = get_type_info((PyTypeObject *) rec.bases[0].ptr());
             assert(parent_tinfo != nullptr);
             bool parent_simple_ancestors = parent_tinfo->simple_ancestors;
@@ -1235,25 +1310,23 @@ class generic_type : public object {
     void mark_parents_nonsimple(PyTypeObject *value) {
         auto t = reinterpret_borrow<tuple>(value->tp_bases);
         for (handle h : t) {
-            auto tinfo2 = get_type_info((PyTypeObject *) h.ptr());
+            auto *tinfo2 = get_type_info((PyTypeObject *) h.ptr());
             if (tinfo2)
                 tinfo2->simple_type = false;
             mark_parents_nonsimple((PyTypeObject *) h.ptr());
         }
     }
 
-    void install_buffer_funcs(
-            buffer_info *(*get_buffer)(PyObject *, void *),
-            void *get_buffer_data) {
-        auto *type = (PyHeapTypeObject*) m_ptr;
-        auto tinfo = detail::get_type_info(&type->ht_type);
+    void install_buffer_funcs(buffer_info *(*get_buffer)(PyObject *, void *),
+                              void *get_buffer_data) {
+        auto *type = (PyHeapTypeObject *) m_ptr;
+        auto *tinfo = detail::get_type_info(&type->ht_type);
 
         if (!type->ht_type.tp_as_buffer)
-            pybind11_fail(
-                "To be able to register buffer protocol support for the type '" +
-                get_fully_qualified_tp_name(tinfo->type) +
-                "' the associated class<>(..) invocation must "
-                "include the pybind11::buffer_protocol() annotation!");
+            pybind11_fail("To be able to register buffer protocol support for the type '"
+                          + get_fully_qualified_tp_name(tinfo->type)
+                          + "' the associated class<>(..) invocation must "
+                            "include the pybind11::buffer_protocol() annotation!");
 
         tinfo->get_buffer = get_buffer;
         tinfo->get_buffer_data = get_buffer_data;
@@ -1261,58 +1334,76 @@ class generic_type : public object {
 
     // rec_func must be set for either fget or fset.
     void def_property_static_impl(const char *name,
-                                  handle fget, handle fset,
+                                  handle fget,
+                                  handle fset,
                                   detail::function_record *rec_func) {
         const auto is_static = (rec_func != nullptr) && !(rec_func->is_method && rec_func->scope);
         const auto has_doc = (rec_func != nullptr) && (rec_func->doc != nullptr)
                              && pybind11::options::show_user_defined_docstrings();
-        auto property = handle((PyObject *) (is_static ? get_internals().static_property_type
-                                                       : &PyProperty_Type));
+        auto property = handle(
+            (PyObject *) (is_static ? get_internals().static_property_type : &PyProperty_Type));
         attr(name) = property(fget.ptr() ? fget : none(),
                               fset.ptr() ? fset : none(),
-                              /*deleter*/none(),
+                              /*deleter*/ none(),
                               pybind11::str(has_doc ? rec_func->doc : ""));
     }
 };
 
 /// Set the pointer to operator new if it exists. The cast is needed because it can be overloaded.
-template <typename T, typename = void_t<decltype(static_cast<void *(*)(size_t)>(T::operator new))>>
-void set_operator_new(type_record *r) { r->operator_new = &T::operator new; }
-
-template <typename> void set_operator_new(...) { }
+template <typename T,
+          typename = void_t<decltype(static_cast<void *(*) (size_t)>(T::operator new))>>
+void set_operator_new(type_record *r) {
+    r->operator_new = &T::operator new;
+}
 
-template <typename T, typename SFINAE = void> struct has_operator_delete : std::false_type { };
-template <typename T> struct has_operator_delete<T, void_t<decltype(static_cast<void (*)(void *)>(T::operator delete))>>
-    : std::true_type { };
-template <typename T, typename SFINAE = void> struct has_operator_delete_size : std::false_type { };
-template <typename T> struct has_operator_delete_size<T, void_t<decltype(static_cast<void (*)(void *, size_t)>(T::operator delete))>>
-    : std::true_type { };
+template <typename>
+void set_operator_new(...) {}
+
+template <typename T, typename SFINAE = void>
+struct has_operator_delete : std::false_type {};
+template <typename T>
+struct has_operator_delete<T, void_t<decltype(static_cast<void (*)(void *)>(T::operator delete))>>
+    : std::true_type {};
+template <typename T, typename SFINAE = void>
+struct has_operator_delete_size : std::false_type {};
+template <typename T>
+struct has_operator_delete_size<
+    T,
+    void_t<decltype(static_cast<void (*)(void *, size_t)>(T::operator delete))>> : std::true_type {
+};
 /// Call class-specific delete if it exists or global otherwise. Can also be an overload set.
 template <typename T, enable_if_t<has_operator_delete<T>::value, int> = 0>
-void call_operator_delete(T *p, size_t, size_t) { T::operator delete(p); }
-template <typename T, enable_if_t<!has_operator_delete<T>::value && has_operator_delete_size<T>::value, int> = 0>
-void call_operator_delete(T *p, size_t s, size_t) { T::operator delete(p, s); }
+void call_operator_delete(T *p, size_t, size_t) {
+    T::operator delete(p);
+}
+template <
+    typename T,
+    enable_if_t<!has_operator_delete<T>::value && has_operator_delete_size<T>::value, int> = 0>
+void call_operator_delete(T *p, size_t s, size_t) {
+    T::operator delete(p, s);
+}
 
 inline void call_operator_delete(void *p, size_t s, size_t a) {
-    (void)s; (void)a;
-    #if defined(__cpp_aligned_new) && (!defined(_MSC_VER) || _MSC_VER >= 1912)
-        if (a > __STDCPP_DEFAULT_NEW_ALIGNMENT__) {
-            #ifdef __cpp_sized_deallocation
-                ::operator delete(p, s, std::align_val_t(a));
-            #else
-                ::operator delete(p, std::align_val_t(a));
-            #endif
-            return;
-        }
-    #endif
-    #ifdef __cpp_sized_deallocation
-        ::operator delete(p, s);
-    #else
-        ::operator delete(p);
-    #endif
+    (void) s;
+    (void) a;
+#if defined(__cpp_aligned_new) && (!defined(_MSC_VER) || _MSC_VER >= 1912)
+    if (a > __STDCPP_DEFAULT_NEW_ALIGNMENT__) {
+#    ifdef __cpp_sized_deallocation
+        ::operator delete(p, s, std::align_val_t(a));
+#    else
+        ::operator delete(p, std::align_val_t(a));
+#    endif
+        return;
+    }
+#endif
+#ifdef __cpp_sized_deallocation
+    ::operator delete(p, s);
+#else
+    ::operator delete(p);
+#endif
 }
 
-inline void add_class_method(object& cls, const char *name_, const cpp_function &cf) {
+inline void add_class_method(object &cls, const char *name_, const cpp_function &cf) {
     cls.attr(cf.name()) = cf;
     if (std::strcmp(name_, "__eq__") == 0 && !cls.attr("__dict__").contains("__hash__")) {
         cls.attr("__hash__") = none();
@@ -1324,30 +1415,37 @@ PYBIND11_NAMESPACE_END(detail)
 /// Given a pointer to a member function, cast it to its `Derived` version.
 /// Forward everything else unchanged.
 template <typename /*Derived*/, typename F>
-auto method_adaptor(F &&f) -> decltype(std::forward<F>(f)) { return std::forward<F>(f); }
+auto method_adaptor(F &&f) -> decltype(std::forward<F>(f)) {
+    return std::forward<F>(f);
+}
 
 template <typename Derived, typename Return, typename Class, typename... Args>
 auto method_adaptor(Return (Class::*pmf)(Args...)) -> Return (Derived::*)(Args...) {
-    static_assert(detail::is_accessible_base_of<Class, Derived>::value,
+    static_assert(
+        detail::is_accessible_base_of<Class, Derived>::value,
         "Cannot bind an inaccessible base class method; use a lambda definition instead");
     return pmf;
 }
 
 template <typename Derived, typename Return, typename Class, typename... Args>
 auto method_adaptor(Return (Class::*pmf)(Args...) const) -> Return (Derived::*)(Args...) const {
-    static_assert(detail::is_accessible_base_of<Class, Derived>::value,
+    static_assert(
+        detail::is_accessible_base_of<Class, Derived>::value,
         "Cannot bind an inaccessible base class method; use a lambda definition instead");
     return pmf;
 }
 
 template <typename type_, typename... options>
 class class_ : public detail::generic_type {
-    template <typename T> using is_holder = detail::is_holder_type<type_, T>;
-    template <typename T> using is_subtype = detail::is_strict_base_of<type_, T>;
-    template <typename T> using is_base = detail::is_strict_base_of<T, type_>;
+    template <typename T>
+    using is_holder = detail::is_holder_type<type_, T>;
+    template <typename T>
+    using is_subtype = detail::is_strict_base_of<type_, T>;
+    template <typename T>
+    using is_base = detail::is_strict_base_of<T, type_>;
     // struct instead of using here to help MSVC:
-    template <typename T> struct is_valid_class_option :
-        detail::any_of<is_holder<T>, is_subtype<T>, is_base<T>> {};
+    template <typename T>
+    struct is_valid_class_option : detail::any_of<is_holder<T>, is_subtype<T>, is_base<T>> {};
 
 public:
     using type = type_;
@@ -1356,23 +1454,24 @@ class class_ : public detail::generic_type {
     using holder_type = detail::exactly_one_t<is_holder, std::unique_ptr<type>, options...>;
 
     static_assert(detail::all_of<is_valid_class_option<options>...>::value,
-            "Unknown/invalid class_ template parameters provided");
+                  "Unknown/invalid class_ template parameters provided");
 
     static_assert(!has_alias || std::is_polymorphic<type>::value,
-            "Cannot use an alias class with a non-polymorphic type");
+                  "Cannot use an alias class with a non-polymorphic type");
 
     PYBIND11_OBJECT(class_, generic_type, PyType_Check)
 
     template <typename... Extra>
-    class_(handle scope, const char *name, const Extra &... extra) {
+    class_(handle scope, const char *name, const Extra &...extra) {
         using namespace detail;
 
         // MI can only be specified via class_ template options, not constructor parameters
         static_assert(
             none_of<is_pyobject<Extra>...>::value || // no base class arguments, or:
-            (   constexpr_sum(is_pyobject<Extra>::value...) == 1 && // Exactly one base
-                constexpr_sum(is_base<options>::value...)   == 0 && // no template option bases
-                none_of<std::is_same<multiple_inheritance, Extra>...>::value), // no multiple_inheritance attr
+                (constexpr_sum(is_pyobject<Extra>::value...) == 1 && // Exactly one base
+                 constexpr_sum(is_base<options>::value...) == 0 &&   // no template option bases
+                 none_of<std::is_same<multiple_inheritance,
+                                      Extra>...>::value), // no multiple_inheritance attr
             "Error: multiple inheritance bases must be specified via class_ template options");
 
         type_record record;
@@ -1380,7 +1479,7 @@ class class_ : public detail::generic_type {
         record.name = name;
         record.type = &typeid(type);
         record.type_size = sizeof(conditional_t<has_alias, type_alias, type>);
-        record.type_align = alignof(conditional_t<has_alias, type_alias, type>&);
+        record.type_align = alignof(conditional_t<has_alias, type_alias, type> &);
         record.holder_size = sizeof(holder_type);
         record.init_instance = init_instance;
         record.dealloc = dealloc;
@@ -1397,8 +1496,10 @@ class class_ : public detail::generic_type {
         generic_type::initialize(record);
 
         if (has_alias) {
-            auto &instances = record.module_local ? get_local_internals().registered_types_cpp : get_internals().registered_types_cpp;
-            instances[std::type_index(typeid(type_alias))] = instances[std::type_index(typeid(type))];
+            auto &instances = record.module_local ? get_local_internals().registered_types_cpp
+                                                  : get_internals().registered_types_cpp;
+            instances[std::type_index(typeid(type_alias))]
+                = instances[std::type_index(typeid(type))];
         }
     }
 
@@ -1410,54 +1511,60 @@ class class_ : public detail::generic_type {
     }
 
     template <typename Base, detail::enable_if_t<!is_base<Base>::value, int> = 0>
-    static void add_base(detail::type_record &) { }
+    static void add_base(detail::type_record &) {}
 
     template <typename Func, typename... Extra>
-    class_ &def(const char *name_, Func&& f, const Extra&... extra) {
-        cpp_function cf(method_adaptor<type>(std::forward<Func>(f)), name(name_), is_method(*this),
-                        sibling(getattr(*this, name_, none())), extra...);
+    class_ &def(const char *name_, Func &&f, const Extra &...extra) {
+        cpp_function cf(method_adaptor<type>(std::forward<Func>(f)),
+                        name(name_),
+                        is_method(*this),
+                        sibling(getattr(*this, name_, none())),
+                        extra...);
         add_class_method(*this, name_, cf);
         return *this;
     }
 
-    template <typename Func, typename... Extra> class_ &
-    def_static(const char *name_, Func &&f, const Extra&... extra) {
+    template <typename Func, typename... Extra>
+    class_ &def_static(const char *name_, Func &&f, const Extra &...extra) {
         static_assert(!std::is_member_function_pointer<Func>::value,
-                "def_static(...) called with a non-static member function pointer");
-        cpp_function cf(std::forward<Func>(f), name(name_), scope(*this),
-                        sibling(getattr(*this, name_, none())), extra...);
+                      "def_static(...) called with a non-static member function pointer");
+        cpp_function cf(std::forward<Func>(f),
+                        name(name_),
+                        scope(*this),
+                        sibling(getattr(*this, name_, none())),
+                        extra...);
         attr(cf.name()) = staticmethod(cf);
         return *this;
     }
 
     template <detail::op_id id, detail::op_type ot, typename L, typename R, typename... Extra>
-    class_ &def(const detail::op_<id, ot, L, R> &op, const Extra&... extra) {
+    class_ &def(const detail::op_<id, ot, L, R> &op, const Extra &...extra) {
         op.execute(*this, extra...);
         return *this;
     }
 
     template <detail::op_id id, detail::op_type ot, typename L, typename R, typename... Extra>
-    class_ & def_cast(const detail::op_<id, ot, L, R> &op, const Extra&... extra) {
+    class_ &def_cast(const detail::op_<id, ot, L, R> &op, const Extra &...extra) {
         op.execute_cast(*this, extra...);
         return *this;
     }
 
     template <typename... Args, typename... Extra>
-    class_ &def(const detail::initimpl::constructor<Args...> &init, const Extra&... extra) {
+    class_ &def(const detail::initimpl::constructor<Args...> &init, const Extra &...extra) {
         PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(init);
         init.execute(*this, extra...);
         return *this;
     }
 
     template <typename... Args, typename... Extra>
-    class_ &def(const detail::initimpl::alias_constructor<Args...> &init, const Extra&... extra) {
+    class_ &def(const detail::initimpl::alias_constructor<Args...> &init, const Extra &...extra) {
         PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(init);
         init.execute(*this, extra...);
         return *this;
     }
 
     template <typename... Args, typename... Extra>
-    class_ &def(detail::initimpl::factory<Args...> &&init, const Extra&... extra) {
+    class_ &def(detail::initimpl::factory<Args...> &&init, const Extra &...extra) {
         std::move(init).execute(*this, extra...);
         return *this;
     }
@@ -1469,51 +1576,58 @@ class class_ : public detail::generic_type {
     }
 
     template <typename Func>
-    class_& def_buffer(Func &&func) {
-        struct capture { Func func; };
-        auto *ptr = new capture { std::forward<Func>(func) };
-        install_buffer_funcs([](PyObject *obj, void *ptr) -> buffer_info* {
-            detail::make_caster<type> caster;
-            if (!caster.load(obj, false))
-                return nullptr;
-            return new buffer_info(((capture *) ptr)->func(caster));
-        }, ptr);
+    class_ &def_buffer(Func &&func) {
+        struct capture {
+            Func func;
+        };
+        auto *ptr = new capture{std::forward<Func>(func)};
+        install_buffer_funcs(
+            [](PyObject *obj, void *ptr) -> buffer_info * {
+                detail::make_caster<type> caster;
+                if (!caster.load(obj, false))
+                    return nullptr;
+                return new buffer_info(((capture *) ptr)->func(caster));
+            },
+            ptr);
         weakref(m_ptr, cpp_function([ptr](handle wr) {
-            delete ptr;
-            wr.dec_ref();
-        })).release();
+                    delete ptr;
+                    wr.dec_ref();
+                }))
+            .release();
         return *this;
     }
 
     template <typename Return, typename Class, typename... Args>
     class_ &def_buffer(Return (Class::*func)(Args...)) {
-        return def_buffer([func] (type &obj) { return (obj.*func)(); });
+        return def_buffer([func](type &obj) { return (obj.*func)(); });
     }
 
     template <typename Return, typename Class, typename... Args>
     class_ &def_buffer(Return (Class::*func)(Args...) const) {
-        return def_buffer([func] (const type &obj) { return (obj.*func)(); });
+        return def_buffer([func](const type &obj) { return (obj.*func)(); });
     }
 
     template <typename C, typename D, typename... Extra>
-    class_ &def_readwrite(const char *name, D C::*pm, const Extra&... extra) {
-        static_assert(std::is_same<C, type>::value || std::is_base_of<C, type>::value, "def_readwrite() requires a class member (or base class member)");
-        cpp_function fget([pm](const type &c) -> const D &{ return c.*pm; }, is_method(*this)),
-                     fset([pm](type &c, const D &value) { c.*pm = value; }, is_method(*this));
+    class_ &def_readwrite(const char *name, D C::*pm, const Extra &...extra) {
+        static_assert(std::is_same<C, type>::value || std::is_base_of<C, type>::value,
+                      "def_readwrite() requires a class member (or base class member)");
+        cpp_function fget([pm](const type &c) -> const D & { return c.*pm; }, is_method(*this)),
+            fset([pm](type &c, const D &value) { c.*pm = value; }, is_method(*this));
         def_property(name, fget, fset, return_value_policy::reference_internal, extra...);
         return *this;
     }
 
     template <typename C, typename D, typename... Extra>
-    class_ &def_readonly(const char *name, const D C::*pm, const Extra& ...extra) {
-        static_assert(std::is_same<C, type>::value || std::is_base_of<C, type>::value, "def_readonly() requires a class member (or base class member)");
-        cpp_function fget([pm](const type &c) -> const D &{ return c.*pm; }, is_method(*this));
+    class_ &def_readonly(const char *name, const D C::*pm, const Extra &...extra) {
+        static_assert(std::is_same<C, type>::value || std::is_base_of<C, type>::value,
+                      "def_readonly() requires a class member (or base class member)");
+        cpp_function fget([pm](const type &c) -> const D & { return c.*pm; }, is_method(*this));
         def_property_readonly(name, fget, return_value_policy::reference_internal, extra...);
         return *this;
     }
 
     template <typename D, typename... Extra>
-    class_ &def_readwrite_static(const char *name, D *pm, const Extra& ...extra) {
+    class_ &def_readwrite_static(const char *name, D *pm, const Extra &...extra) {
         cpp_function fget([pm](const object &) -> const D & { return *pm; }, scope(*this)),
             fset([pm](const object &, const D &value) { *pm = value; }, scope(*this));
         def_property_static(name, fget, fset, return_value_policy::reference, extra...);
@@ -1521,7 +1635,7 @@ class class_ : public detail::generic_type {
     }
 
     template <typename D, typename... Extra>
-    class_ &def_readonly_static(const char *name, const D *pm, const Extra& ...extra) {
+    class_ &def_readonly_static(const char *name, const D *pm, const Extra &...extra) {
         cpp_function fget([pm](const object &) -> const D & { return *pm; }, scope(*this));
         def_property_readonly_static(name, fget, return_value_policy::reference, extra...);
         return *this;
@@ -1529,66 +1643,91 @@ class class_ : public detail::generic_type {
 
     /// Uses return_value_policy::reference_internal by default
     template <typename Getter, typename... Extra>
-    class_ &def_property_readonly(const char *name, const Getter &fget, const Extra& ...extra) {
-        return def_property_readonly(name, cpp_function(method_adaptor<type>(fget)),
-                                     return_value_policy::reference_internal, extra...);
+    class_ &def_property_readonly(const char *name, const Getter &fget, const Extra &...extra) {
+        return def_property_readonly(name,
+                                     cpp_function(method_adaptor<type>(fget)),
+                                     return_value_policy::reference_internal,
+                                     extra...);
     }
 
     /// Uses cpp_function's return_value_policy by default
     template <typename... Extra>
-    class_ &def_property_readonly(const char *name, const cpp_function &fget, const Extra& ...extra) {
+    class_ &
+    def_property_readonly(const char *name, const cpp_function &fget, const Extra &...extra) {
         return def_property(name, fget, nullptr, extra...);
     }
 
     /// Uses return_value_policy::reference by default
     template <typename Getter, typename... Extra>
-    class_ &def_property_readonly_static(const char *name, const Getter &fget, const Extra& ...extra) {
-        return def_property_readonly_static(name, cpp_function(fget), return_value_policy::reference, extra...);
+    class_ &
+    def_property_readonly_static(const char *name, const Getter &fget, const Extra &...extra) {
+        return def_property_readonly_static(
+            name, cpp_function(fget), return_value_policy::reference, extra...);
     }
 
     /// Uses cpp_function's return_value_policy by default
     template <typename... Extra>
-    class_ &def_property_readonly_static(const char *name, const cpp_function &fget, const Extra& ...extra) {
+    class_ &def_property_readonly_static(const char *name,
+                                         const cpp_function &fget,
+                                         const Extra &...extra) {
         return def_property_static(name, fget, nullptr, extra...);
     }
 
     /// Uses return_value_policy::reference_internal by default
     template <typename Getter, typename Setter, typename... Extra>
-    class_ &def_property(const char *name, const Getter &fget, const Setter &fset, const Extra& ...extra) {
+    class_ &
+    def_property(const char *name, const Getter &fget, const Setter &fset, const Extra &...extra) {
         return def_property(name, fget, cpp_function(method_adaptor<type>(fset)), extra...);
     }
     template <typename Getter, typename... Extra>
-    class_ &def_property(const char *name, const Getter &fget, const cpp_function &fset, const Extra& ...extra) {
-        return def_property(name, cpp_function(method_adaptor<type>(fget)), fset,
-                            return_value_policy::reference_internal, extra...);
+    class_ &def_property(const char *name,
+                         const Getter &fget,
+                         const cpp_function &fset,
+                         const Extra &...extra) {
+        return def_property(name,
+                            cpp_function(method_adaptor<type>(fget)),
+                            fset,
+                            return_value_policy::reference_internal,
+                            extra...);
     }
 
     /// Uses cpp_function's return_value_policy by default
     template <typename... Extra>
-    class_ &def_property(const char *name, const cpp_function &fget, const cpp_function &fset, const Extra& ...extra) {
+    class_ &def_property(const char *name,
+                         const cpp_function &fget,
+                         const cpp_function &fset,
+                         const Extra &...extra) {
         return def_property_static(name, fget, fset, is_method(*this), extra...);
     }
 
     /// Uses return_value_policy::reference by default
     template <typename Getter, typename... Extra>
-    class_ &def_property_static(const char *name, const Getter &fget, const cpp_function &fset, const Extra& ...extra) {
-        return def_property_static(name, cpp_function(fget), fset, return_value_policy::reference, extra...);
+    class_ &def_property_static(const char *name,
+                                const Getter &fget,
+                                const cpp_function &fset,
+                                const Extra &...extra) {
+        return def_property_static(
+            name, cpp_function(fget), fset, return_value_policy::reference, extra...);
     }
 
     /// Uses cpp_function's return_value_policy by default
     template <typename... Extra>
-    class_ &def_property_static(const char *name, const cpp_function &fget, const cpp_function &fset, const Extra& ...extra) {
-        static_assert( 0 == detail::constexpr_sum(std::is_base_of<arg, Extra>::value...),
+    class_ &def_property_static(const char *name,
+                                const cpp_function &fget,
+                                const cpp_function &fset,
+                                const Extra &...extra) {
+        static_assert(0 == detail::constexpr_sum(std::is_base_of<arg, Extra>::value...),
                       "Argument annotations are not allowed for properties");
         auto rec_fget = get_function_record(fget), rec_fset = get_function_record(fset);
         auto *rec_active = rec_fget;
         if (rec_fget) {
-           char *doc_prev = rec_fget->doc; /* 'extra' field may include a property-specific documentation string */
-           detail::process_attributes<Extra...>::init(extra..., rec_fget);
-           if (rec_fget->doc && rec_fget->doc != doc_prev) {
-              std::free(doc_prev);
-              rec_fget->doc = PYBIND11_COMPAT_STRDUP(rec_fget->doc);
-           }
+            char *doc_prev = rec_fget->doc; /* 'extra' field may include a property-specific
+                                               documentation string */
+            detail::process_attributes<Extra...>::init(extra..., rec_fget);
+            if (rec_fget->doc && rec_fget->doc != doc_prev) {
+                std::free(doc_prev);
+                rec_fget->doc = PYBIND11_COMPAT_STRDUP(rec_fget->doc);
+            }
         }
         if (rec_fset) {
             char *doc_prev = rec_fset->doc;
@@ -1597,7 +1736,8 @@ class class_ : public detail::generic_type {
                 std::free(doc_prev);
                 rec_fset->doc = PYBIND11_COMPAT_STRDUP(rec_fset->doc);
             }
-            if (! rec_active) rec_active = rec_fset;
+            if (!rec_active)
+                rec_active = rec_fset;
         }
         def_property_static_impl(name, fget, fset, rec_active);
         return *this;
@@ -1606,11 +1746,13 @@ class class_ : public detail::generic_type {
 private:
     /// Initialize holder object, variant 1: object derives from enable_shared_from_this
     template <typename T>
-    static void init_holder(detail::instance *inst, detail::value_and_holder &v_h,
-            const holder_type * /* unused */, const std::enable_shared_from_this<T> * /* dummy */) {
+    static void init_holder(detail::instance *inst,
+                            detail::value_and_holder &v_h,
+                            const holder_type * /* unused */,
+                            const std::enable_shared_from_this<T> * /* dummy */) {
 
         auto sh = std::dynamic_pointer_cast<typename holder_type::element_type>(
-                detail::try_get_shared_from_this(v_h.value_ptr<type>()));
+            detail::try_get_shared_from_this(v_h.value_ptr<type>()));
         if (sh) {
             new (std::addressof(v_h.holder<holder_type>())) holder_type(std::move(sh));
             v_h.set_holder_constructed();
@@ -1623,18 +1765,25 @@ class class_ : public detail::generic_type {
     }
 
     static void init_holder_from_existing(const detail::value_and_holder &v_h,
-            const holder_type *holder_ptr, std::true_type /*is_copy_constructible*/) {
-        new (std::addressof(v_h.holder<holder_type>())) holder_type(*reinterpret_cast<const holder_type *>(holder_ptr));
+                                          const holder_type *holder_ptr,
+                                          std::true_type /*is_copy_constructible*/) {
+        new (std::addressof(v_h.holder<holder_type>()))
+            holder_type(*reinterpret_cast<const holder_type *>(holder_ptr));
     }
 
     static void init_holder_from_existing(const detail::value_and_holder &v_h,
-            const holder_type *holder_ptr, std::false_type /*is_copy_constructible*/) {
-        new (std::addressof(v_h.holder<holder_type>())) holder_type(std::move(*const_cast<holder_type *>(holder_ptr)));
-    }
-
-    /// Initialize holder object, variant 2: try to construct from existing holder object, if possible
-    static void init_holder(detail::instance *inst, detail::value_and_holder &v_h,
-            const holder_type *holder_ptr, const void * /* dummy -- not enable_shared_from_this<T>) */) {
+                                          const holder_type *holder_ptr,
+                                          std::false_type /*is_copy_constructible*/) {
+        new (std::addressof(v_h.holder<holder_type>()))
+            holder_type(std::move(*const_cast<holder_type *>(holder_ptr)));
+    }
+
+    /// Initialize holder object, variant 2: try to construct from existing holder object, if
+    /// possible
+    static void init_holder(detail::instance *inst,
+                            detail::value_and_holder &v_h,
+                            const holder_type *holder_ptr,
+                            const void * /* dummy -- not enable_shared_from_this<T>) */) {
         if (holder_ptr) {
             init_holder_from_existing(v_h, holder_ptr, std::is_copy_constructible<holder_type>());
             v_h.set_holder_constructed();
@@ -1645,8 +1794,8 @@ class class_ : public detail::generic_type {
     }
 
     /// Performs instance initialization including constructing a holder and registering the known
-    /// instance.  Should be called as soon as the `type` value_ptr is set for an instance.  Takes an
-    /// optional pointer to an existing holder to use; if not specified and the instance is
+    /// instance.  Should be called as soon as the `type` value_ptr is set for an instance.  Takes
+    /// an optional pointer to an existing holder to use; if not specified and the instance is
     /// `.owned`, a new holder will be constructed to manage the value pointer.
     static void init_instance(detail::instance *inst, const void *holder_ptr) {
         auto v_h = inst->get_value_and_holder(detail::get_type_info(typeid(type)));
@@ -1669,35 +1818,42 @@ class class_ : public detail::generic_type {
         if (v_h.holder_constructed()) {
             v_h.holder<holder_type>().~holder_type();
             v_h.set_holder_constructed(false);
-        }
-        else {
-            detail::call_operator_delete(v_h.value_ptr<type>(),
-                v_h.type->type_size,
-                v_h.type->type_align
-            );
+        } else {
+            detail::call_operator_delete(
+                v_h.value_ptr<type>(), v_h.type->type_size, v_h.type->type_align);
         }
         v_h.value_ptr() = nullptr;
     }
 
     static detail::function_record *get_function_record(handle h) {
         h = detail::get_function(h);
-        return h ? (detail::function_record *) reinterpret_borrow<capsule>(PyCFunction_GET_SELF(h.ptr()))
+        return h ? (detail::function_record *) reinterpret_borrow<capsule>(
+                   PyCFunction_GET_SELF(h.ptr()))
                  : nullptr;
     }
 };
 
 /// Binds an existing constructor taking arguments Args...
-template <typename... Args> detail::initimpl::constructor<Args...> init() { return {}; }
+template <typename... Args>
+detail::initimpl::constructor<Args...> init() {
+    return {};
+}
 /// Like `init<Args...>()`, but the instance is always constructed through the alias class (even
 /// when not inheriting on the Python side).
-template <typename... Args> detail::initimpl::alias_constructor<Args...> init_alias() { return {}; }
+template <typename... Args>
+detail::initimpl::alias_constructor<Args...> init_alias() {
+    return {};
+}
 
 /// Binds a factory function as a constructor
 template <typename Func, typename Ret = detail::initimpl::factory<Func>>
-Ret init(Func &&f) { return {std::forward<Func>(f)}; }
+Ret init(Func &&f) {
+    return {std::forward<Func>(f)};
+}
 
-/// Dual-argument factory function: the first function is called when no alias is needed, the second
-/// when an alias is needed (i.e. due to python-side inheritance).  Arguments must be identical.
+/// Dual-argument factory function: the first function is called when no alias is needed, the
+/// second when an alias is needed (i.e. due to python-side inheritance).  Arguments must be
+/// identical.
 template <typename CFunc, typename AFunc, typename Ret = detail::initimpl::factory<CFunc, AFunc>>
 Ret init(CFunc &&c, AFunc &&a) {
     return {std::forward<CFunc>(c), std::forward<AFunc>(a)};
@@ -1722,7 +1878,7 @@ inline str enum_name(handle arg) {
 }
 
 struct enum_base {
-    enum_base(const handle &base, const handle &parent) : m_base(base), m_parent(parent) { }
+    enum_base(const handle &base, const handle &parent) : m_base(base), m_parent(parent) {}
 
     PYBIND11_NOINLINE void init(bool is_arithmetic, bool is_convertible) {
         m_base.attr("__entries") = dict();
@@ -1744,35 +1900,44 @@ struct enum_base {
             [](handle arg) -> str {
                 object type_name = type::handle_of(arg).attr("__name__");
                 return pybind11::str("{}.{}").format(type_name, enum_name(arg));
-            }, name("name"), is_method(m_base)
-        );
+            },
+            name("name"),
+            is_method(m_base));
 
-        m_base.attr("__doc__") = static_property(cpp_function(
-            [](handle arg) -> std::string {
-                std::string docstring;
-                dict entries = arg.attr("__entries");
-                if (((PyTypeObject *) arg.ptr())->tp_doc)
-                    docstring += std::string(((PyTypeObject *) arg.ptr())->tp_doc) + "\n\n";
-                docstring += "Members:";
-                for (auto kv : entries) {
-                    auto key = std::string(pybind11::str(kv.first));
-                    auto comment = kv.second[int_(1)];
-                    docstring += "\n\n  " + key;
-                    if (!comment.is_none())
-                        docstring += " : " + (std::string) pybind11::str(comment);
-                }
-                return docstring;
-            }, name("__doc__")
-        ), none(), none(), "");
+        m_base.attr("__doc__") = static_property(
+            cpp_function(
+                [](handle arg) -> std::string {
+                    std::string docstring;
+                    dict entries = arg.attr("__entries");
+                    if (((PyTypeObject *) arg.ptr())->tp_doc)
+                        docstring += std::string(((PyTypeObject *) arg.ptr())->tp_doc) + "\n\n";
+                    docstring += "Members:";
+                    for (auto kv : entries) {
+                        auto key = std::string(pybind11::str(kv.first));
+                        auto comment = kv.second[int_(1)];
+                        docstring += "\n\n  " + key;
+                        if (!comment.is_none())
+                            docstring += " : " + (std::string) pybind11::str(comment);
+                    }
+                    return docstring;
+                },
+                name("__doc__")),
+            none(),
+            none(),
+            "");
 
         m_base.attr("__members__") = static_property(cpp_function(
-            [](handle arg) -> dict {
-                dict entries = arg.attr("__entries"), m;
-                for (auto kv : entries)
-                    m[kv.first] = kv.second[int_(0)];
-                return m;
-            }, name("__members__")), none(), none(), ""
-        );
+                                                         [](handle arg) -> dict {
+                                                             dict entries = arg.attr("__entries"),
+                                                                  m;
+                                                             for (auto kv : entries)
+                                                                 m[kv.first] = kv.second[int_(0)];
+                                                             return m;
+                                                         },
+                                                         name("__members__")),
+                                                     none(),
+                                                     none(),
+                                                     "");
 
 #define PYBIND11_ENUM_OP_STRICT(op, expr, strict_behavior)                                        \
     m_base.attr(op) = cpp_function(                                                               \
@@ -1806,42 +1971,42 @@ struct enum_base {
         arg("other"))
 
         if (is_convertible) {
-            PYBIND11_ENUM_OP_CONV_LHS("__eq__", !b.is_none() &&  a.equal(b));
-            PYBIND11_ENUM_OP_CONV_LHS("__ne__",  b.is_none() || !a.equal(b));
+            PYBIND11_ENUM_OP_CONV_LHS("__eq__", !b.is_none() && a.equal(b));
+            PYBIND11_ENUM_OP_CONV_LHS("__ne__", b.is_none() || !a.equal(b));
 
             if (is_arithmetic) {
-                PYBIND11_ENUM_OP_CONV("__lt__",   a <  b);
-                PYBIND11_ENUM_OP_CONV("__gt__",   a >  b);
-                PYBIND11_ENUM_OP_CONV("__le__",   a <= b);
-                PYBIND11_ENUM_OP_CONV("__ge__",   a >= b);
-                PYBIND11_ENUM_OP_CONV("__and__",  a &  b);
-                PYBIND11_ENUM_OP_CONV("__rand__", a &  b);
-                PYBIND11_ENUM_OP_CONV("__or__",   a |  b);
-                PYBIND11_ENUM_OP_CONV("__ror__",  a |  b);
-                PYBIND11_ENUM_OP_CONV("__xor__",  a ^  b);
-                PYBIND11_ENUM_OP_CONV("__rxor__", a ^  b);
+                PYBIND11_ENUM_OP_CONV("__lt__", a < b);
+                PYBIND11_ENUM_OP_CONV("__gt__", a > b);
+                PYBIND11_ENUM_OP_CONV("__le__", a <= b);
+                PYBIND11_ENUM_OP_CONV("__ge__", a >= b);
+                PYBIND11_ENUM_OP_CONV("__and__", a & b);
+                PYBIND11_ENUM_OP_CONV("__rand__", a & b);
+                PYBIND11_ENUM_OP_CONV("__or__", a | b);
+                PYBIND11_ENUM_OP_CONV("__ror__", a | b);
+                PYBIND11_ENUM_OP_CONV("__xor__", a ^ b);
+                PYBIND11_ENUM_OP_CONV("__rxor__", a ^ b);
                 m_base.attr("__invert__")
                     = cpp_function([](const object &arg) { return ~(int_(arg)); },
                                    name("__invert__"),
                                    is_method(m_base));
             }
         } else {
-            PYBIND11_ENUM_OP_STRICT("__eq__",  int_(a).equal(int_(b)), return false);
+            PYBIND11_ENUM_OP_STRICT("__eq__", int_(a).equal(int_(b)), return false);
             PYBIND11_ENUM_OP_STRICT("__ne__", !int_(a).equal(int_(b)), return true);
 
             if (is_arithmetic) {
-                #define PYBIND11_THROW throw type_error("Expected an enumeration of matching type!");
-                PYBIND11_ENUM_OP_STRICT("__lt__", int_(a) <  int_(b), PYBIND11_THROW);
-                PYBIND11_ENUM_OP_STRICT("__gt__", int_(a) >  int_(b), PYBIND11_THROW);
+#define PYBIND11_THROW throw type_error("Expected an enumeration of matching type!");
+                PYBIND11_ENUM_OP_STRICT("__lt__", int_(a) < int_(b), PYBIND11_THROW);
+                PYBIND11_ENUM_OP_STRICT("__gt__", int_(a) > int_(b), PYBIND11_THROW);
                 PYBIND11_ENUM_OP_STRICT("__le__", int_(a) <= int_(b), PYBIND11_THROW);
                 PYBIND11_ENUM_OP_STRICT("__ge__", int_(a) >= int_(b), PYBIND11_THROW);
-                #undef PYBIND11_THROW
+#undef PYBIND11_THROW
             }
         }
 
-        #undef PYBIND11_ENUM_OP_CONV_LHS
-        #undef PYBIND11_ENUM_OP_CONV
-        #undef PYBIND11_ENUM_OP_STRICT
+#undef PYBIND11_ENUM_OP_CONV_LHS
+#undef PYBIND11_ENUM_OP_CONV
+#undef PYBIND11_ENUM_OP_STRICT
 
         m_base.attr("__getstate__") = cpp_function(
             [](const object &arg) { return int_(arg); }, name("__getstate__"), is_method(m_base));
@@ -1850,12 +2015,13 @@ struct enum_base {
             [](const object &arg) { return int_(arg); }, name("__hash__"), is_method(m_base));
     }
 
-    PYBIND11_NOINLINE void value(char const* name_, object value, const char *doc = nullptr) {
+    PYBIND11_NOINLINE void value(char const *name_, object value, const char *doc = nullptr) {
         dict entries = m_base.attr("__entries");
         str name(name_);
         if (entries.contains(name)) {
             std::string type_name = (std::string) str(m_base.attr("__name__"));
-            throw value_error(type_name + ": element \"" + std::string(name_) + "\" already exists!");
+            throw value_error(type_name + ": element \"" + std::string(name_)
+                              + "\" already exists!");
         }
 
         entries[name] = std::make_pair(value, doc);
@@ -1872,38 +2038,66 @@ struct enum_base {
     handle m_parent;
 };
 
-template <bool is_signed, size_t length> struct equivalent_integer {};
-template <> struct equivalent_integer<true,  1> { using type = int8_t;   };
-template <> struct equivalent_integer<false, 1> { using type = uint8_t;  };
-template <> struct equivalent_integer<true,  2> { using type = int16_t;  };
-template <> struct equivalent_integer<false, 2> { using type = uint16_t; };
-template <> struct equivalent_integer<true,  4> { using type = int32_t;  };
-template <> struct equivalent_integer<false, 4> { using type = uint32_t; };
-template <> struct equivalent_integer<true,  8> { using type = int64_t;  };
-template <> struct equivalent_integer<false, 8> { using type = uint64_t; };
+template <bool is_signed, size_t length>
+struct equivalent_integer {};
+template <>
+struct equivalent_integer<true, 1> {
+    using type = int8_t;
+};
+template <>
+struct equivalent_integer<false, 1> {
+    using type = uint8_t;
+};
+template <>
+struct equivalent_integer<true, 2> {
+    using type = int16_t;
+};
+template <>
+struct equivalent_integer<false, 2> {
+    using type = uint16_t;
+};
+template <>
+struct equivalent_integer<true, 4> {
+    using type = int32_t;
+};
+template <>
+struct equivalent_integer<false, 4> {
+    using type = uint32_t;
+};
+template <>
+struct equivalent_integer<true, 8> {
+    using type = int64_t;
+};
+template <>
+struct equivalent_integer<false, 8> {
+    using type = uint64_t;
+};
 
 template <typename IntLike>
-using equivalent_integer_t = typename equivalent_integer<std::is_signed<IntLike>::value, sizeof(IntLike)>::type;
+using equivalent_integer_t =
+    typename equivalent_integer<std::is_signed<IntLike>::value, sizeof(IntLike)>::type;
 
 PYBIND11_NAMESPACE_END(detail)
 
 /// Binds C++ enumerations and enumeration classes to Python
-template <typename Type> class enum_ : public class_<Type> {
+template <typename Type>
+class enum_ : public class_<Type> {
 public:
     using Base = class_<Type>;
-    using Base::def;
     using Base::attr;
+    using Base::def;
     using Base::def_property_readonly;
     using Base::def_property_readonly_static;
     using Underlying = typename std::underlying_type<Type>::type;
     // Scalar is the integer representation of underlying type
-    using Scalar = detail::conditional_t<detail::any_of<
-        detail::is_std_char_type<Underlying>, std::is_same<Underlying, bool>
-    >::value, detail::equivalent_integer_t<Underlying>, Underlying>;
+    using Scalar = detail::conditional_t<detail::any_of<detail::is_std_char_type<Underlying>,
+                                                        std::is_same<Underlying, bool>>::value,
+                                         detail::equivalent_integer_t<Underlying>,
+                                         Underlying>;
 
     template <typename... Extra>
-    enum_(const handle &scope, const char *name, const Extra&... extra)
-      : class_<Type>(scope, name, extra...), m_base(*this, scope) {
+    enum_(const handle &scope, const char *name, const Extra &...extra)
+        : class_<Type>(scope, name, extra...), m_base(*this, scope) {
         constexpr bool is_arithmetic = detail::any_of<std::is_same<arithmetic, Extra>...>::value;
         constexpr bool is_convertible = std::is_convertible<Type, Underlying>::value;
         m_base.init(is_arithmetic, is_convertible);
@@ -1911,29 +2105,32 @@ template <typename Type> class enum_ : public class_<Type> {
         def(init([](Scalar i) { return static_cast<Type>(i); }), arg("value"));
         def_property_readonly("value", [](Type value) { return (Scalar) value; });
         def("__int__", [](Type value) { return (Scalar) value; });
-        #if PY_MAJOR_VERSION < 3
-            def("__long__", [](Type value) { return (Scalar) value; });
-        #endif
-        #if PY_MAJOR_VERSION > 3 || (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 8)
-            def("__index__", [](Type value) { return (Scalar) value; });
-        #endif
+#if PY_MAJOR_VERSION < 3
+        def("__long__", [](Type value) { return (Scalar) value; });
+#endif
+#if PY_MAJOR_VERSION > 3 || (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 8)
+        def("__index__", [](Type value) { return (Scalar) value; });
+#endif
 
         attr("__setstate__") = cpp_function(
             [](detail::value_and_holder &v_h, Scalar arg) {
-                detail::initimpl::setstate<Base>(v_h, static_cast<Type>(arg),
-                        Py_TYPE(v_h.inst) != v_h.type->type); },
+                detail::initimpl::setstate<Base>(
+                    v_h, static_cast<Type>(arg), Py_TYPE(v_h.inst) != v_h.type->type);
+            },
             detail::is_new_style_constructor(),
-            pybind11::name("__setstate__"), is_method(*this), arg("state"));
+            pybind11::name("__setstate__"),
+            is_method(*this),
+            arg("state"));
     }
 
     /// Export enumeration entries into the parent scope
-    enum_& export_values() {
+    enum_ &export_values() {
         m_base.export_values();
         return *this;
     }
 
     /// Add an enumeration entry
-    enum_& value(char const* name, Type value, const char *doc = nullptr) {
+    enum_ &value(char const *name, Type value, const char *doc = nullptr) {
         m_base.value(name, pybind11::cast(value, return_value_policy::copy), doc);
         return *this;
     }
@@ -1944,7 +2141,6 @@ template <typename Type> class enum_ : public class_<Type> {
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 
-
 PYBIND11_NOINLINE void keep_alive_impl(handle nurse, handle patient) {
     if (!nurse || !patient)
         pybind11_fail("Could not activate keep_alive!");
@@ -1957,13 +2153,14 @@ PYBIND11_NOINLINE void keep_alive_impl(handle nurse, handle patient) {
         /* It's a pybind-registered type, so we can store the patient in the
          * internal list. */
         add_patient(nurse.ptr(), patient.ptr());
-    }
-    else {
+    } else {
         /* Fall back to clever approach based on weak references taken from
          * Boost.Python. This is not used for pybind-registered types because
          * the objects can be destroyed out-of-order in a GC pass. */
-        cpp_function disable_lifesupport(
-            [patient](handle weakref) { patient.dec_ref(); weakref.dec_ref(); });
+        cpp_function disable_lifesupport([patient](handle weakref) {
+            patient.dec_ref();
+            weakref.dec_ref();
+        });
 
         weakref wr(nurse, disable_lifesupport);
 
@@ -1972,7 +2169,8 @@ PYBIND11_NOINLINE void keep_alive_impl(handle nurse, handle patient) {
     }
 }
 
-PYBIND11_NOINLINE void keep_alive_impl(size_t Nurse, size_t Patient, function_call &call, handle ret) {
+PYBIND11_NOINLINE void
+keep_alive_impl(size_t Nurse, size_t Patient, function_call &call, handle ret) {
     auto get_arg = [&](size_t n) {
         if (n == 0)
             return ret;
@@ -1986,30 +2184,33 @@ PYBIND11_NOINLINE void keep_alive_impl(size_t Nurse, size_t Patient, function_ca
     keep_alive_impl(get_arg(Nurse), get_arg(Patient));
 }
 
-inline std::pair<decltype(internals::registered_types_py)::iterator, bool> all_type_info_get_cache(PyTypeObject *type) {
-    auto res = get_internals().registered_types_py
+inline std::pair<decltype(internals::registered_types_py)::iterator, bool>
+all_type_info_get_cache(PyTypeObject *type) {
+    auto res = get_internals()
+                   .registered_types_py
 #ifdef __cpp_lib_unordered_map_try_emplace
-        .try_emplace(type);
+                   .try_emplace(type);
 #else
-        .emplace(type, std::vector<detail::type_info *>());
+                   .emplace(type, std::vector<detail::type_info *>());
 #endif
     if (res.second) {
         // New cache entry created; set up a weak reference to automatically remove it if the type
         // gets destroyed:
         weakref((PyObject *) type, cpp_function([type](handle wr) {
-            get_internals().registered_types_py.erase(type);
+                    get_internals().registered_types_py.erase(type);
 
-            // TODO consolidate the erasure code in pybind11_meta_dealloc() in class.h
-            auto &cache = get_internals().inactive_override_cache;
-            for (auto it = cache.begin(), last = cache.end(); it != last; ) {
-                if (it->first == reinterpret_cast<PyObject *>(type))
-                    it = cache.erase(it);
-                else
-                    ++it;
-            }
+                    // TODO consolidate the erasure code in pybind11_meta_dealloc() in class.h
+                    auto &cache = get_internals().inactive_override_cache;
+                    for (auto it = cache.begin(), last = cache.end(); it != last;) {
+                        if (it->first == reinterpret_cast<PyObject *>(type))
+                            it = cache.erase(it);
+                        else
+                            ++it;
+                    }
 
-            wr.dec_ref();
-        })).release();
+                    wr.dec_ref();
+                }))
+            .release();
     }
 
     return res;
@@ -2018,7 +2219,12 @@ inline std::pair<decltype(internals::registered_types_py)::iterator, bool> all_t
 /* There are a large number of apparently unused template arguments because
  * each combination requires a separate py::class_ registration.
  */
-template <typename Access, return_value_policy Policy, typename Iterator, typename Sentinel, typename ValueType, typename... Extra>
+template <typename Access,
+          return_value_policy Policy,
+          typename Iterator,
+          typename Sentinel,
+          typename ValueType,
+          typename... Extra>
 struct iterator_state {
     Iterator it;
     Sentinel end;
@@ -2033,12 +2239,10 @@ template <typename Iterator, typename SFINAE = decltype(*std::declval<Iterator &
 struct iterator_access {
     using result_type = decltype(*std::declval<Iterator &>());
     // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
-    result_type operator()(Iterator &it) const {
-        return *it;
-    }
+    result_type operator()(Iterator &it) const { return *it; }
 };
 
-template <typename Iterator, typename SFINAE = decltype((*std::declval<Iterator &>()).first) >
+template <typename Iterator, typename SFINAE = decltype((*std::declval<Iterator &>()).first)>
 class iterator_key_access {
 private:
     using pair_type = decltype(*std::declval<Iterator &>());
@@ -2053,14 +2257,11 @@ class iterator_key_access {
      * (it's not used in the first branch because going via decltype and back
      * through declval does not perfectly preserve references).
      */
-    using result_type = conditional_t<
-        std::is_reference<decltype(*std::declval<Iterator &>())>::value,
-        decltype(((*std::declval<Iterator &>()).first)),
-        decltype(std::declval<pair_type>().first)
-    >;
-    result_type operator()(Iterator &it) const {
-        return (*it).first;
-    }
+    using result_type
+        = conditional_t<std::is_reference<decltype(*std::declval<Iterator &>())>::value,
+                        decltype(((*std::declval<Iterator &>()).first)),
+                        decltype(std::declval<pair_type>().first)>;
+    result_type operator()(Iterator &it) const { return (*it).first; }
 };
 
 template <typename Iterator, typename SFINAE = decltype((*std::declval<Iterator &>()).second)>
@@ -2069,14 +2270,11 @@ class iterator_value_access {
     using pair_type = decltype(*std::declval<Iterator &>());
 
 public:
-    using result_type = conditional_t<
-        std::is_reference<decltype(*std::declval<Iterator &>())>::value,
-        decltype(((*std::declval<Iterator &>()).second)),
-        decltype(std::declval<pair_type>().second)
-    >;
-    result_type operator()(Iterator &it) const {
-        return (*it).second;
-    }
+    using result_type
+        = conditional_t<std::is_reference<decltype(*std::declval<Iterator &>())>::value,
+                        decltype(((*std::declval<Iterator &>()).second)),
+                        decltype(std::declval<pair_type>().second)>;
+    result_type operator()(Iterator &it) const { return (*it).second; }
 };
 
 template <typename Access,
@@ -2085,25 +2283,29 @@ template <typename Access,
           typename Sentinel,
           typename ValueType,
           typename... Extra>
-iterator make_iterator_impl(Iterator first, Sentinel last, Extra &&... extra) {
+iterator make_iterator_impl(Iterator first, Sentinel last, Extra &&...extra) {
     using state = detail::iterator_state<Access, Policy, Iterator, Sentinel, ValueType, Extra...>;
     // TODO: state captures only the types of Extra, not the values
 
     if (!detail::get_type_info(typeid(state), false)) {
         class_<state>(handle(), "iterator", pybind11::module_local())
-            .def("__iter__", [](state &s) -> state& { return s; })
-            .def("__next__", [](state &s) -> ValueType {
-                if (!s.first_or_done)
-                    ++s.it;
-                else
-                    s.first_or_done = false;
-                if (s.it == s.end) {
-                    s.first_or_done = true;
-                    throw stop_iteration();
-                }
-                return Access()(s.it);
-            // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
-            }, std::forward<Extra>(extra)..., Policy);
+            .def("__iter__", [](state &s) -> state & { return s; })
+            .def(
+                "__next__",
+                [](state &s) -> ValueType {
+                    if (!s.first_or_done)
+                        ++s.it;
+                    else
+                        s.first_or_done = false;
+                    if (s.it == s.end) {
+                        s.first_or_done = true;
+                        throw stop_iteration();
+                    }
+                    return Access()(s.it);
+                    // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
+                },
+                std::forward<Extra>(extra)...,
+                Policy);
     }
 
     return cast(state{first, last, true});
@@ -2117,14 +2319,13 @@ template <return_value_policy Policy = return_value_policy::reference_internal,
           typename Sentinel,
           typename ValueType = typename detail::iterator_access<Iterator>::result_type,
           typename... Extra>
-iterator make_iterator(Iterator first, Sentinel last, Extra &&... extra) {
-    return detail::make_iterator_impl<
-        detail::iterator_access<Iterator>,
-        Policy,
-        Iterator,
-        Sentinel,
-        ValueType,
-        Extra...>(first, last, std::forward<Extra>(extra)...);
+iterator make_iterator(Iterator first, Sentinel last, Extra &&...extra) {
+    return detail::make_iterator_impl<detail::iterator_access<Iterator>,
+                                      Policy,
+                                      Iterator,
+                                      Sentinel,
+                                      ValueType,
+                                      Extra...>(first, last, std::forward<Extra>(extra)...);
 }
 
 /// Makes a python iterator over the keys (`.first`) of a iterator over pairs from a
@@ -2135,13 +2336,12 @@ template <return_value_policy Policy = return_value_policy::reference_internal,
           typename KeyType = typename detail::iterator_key_access<Iterator>::result_type,
           typename... Extra>
 iterator make_key_iterator(Iterator first, Sentinel last, Extra &&...extra) {
-    return detail::make_iterator_impl<
-        detail::iterator_key_access<Iterator>,
-        Policy,
-        Iterator,
-        Sentinel,
-        KeyType,
-        Extra...>(first, last, std::forward<Extra>(extra)...);
+    return detail::make_iterator_impl<detail::iterator_key_access<Iterator>,
+                                      Policy,
+                                      Iterator,
+                                      Sentinel,
+                                      KeyType,
+                                      Extra...>(first, last, std::forward<Extra>(extra)...);
 }
 
 /// Makes a python iterator over the values (`.second`) of a iterator over pairs from a
@@ -2152,36 +2352,43 @@ template <return_value_policy Policy = return_value_policy::reference_internal,
           typename ValueType = typename detail::iterator_value_access<Iterator>::result_type,
           typename... Extra>
 iterator make_value_iterator(Iterator first, Sentinel last, Extra &&...extra) {
-    return detail::make_iterator_impl<
-        detail::iterator_value_access<Iterator>,
-        Policy, Iterator,
-        Sentinel,
-        ValueType,
-        Extra...>(first, last, std::forward<Extra>(extra)...);
+    return detail::make_iterator_impl<detail::iterator_value_access<Iterator>,
+                                      Policy,
+                                      Iterator,
+                                      Sentinel,
+                                      ValueType,
+                                      Extra...>(first, last, std::forward<Extra>(extra)...);
 }
 
 /// Makes an iterator over values of an stl container or other container supporting
 /// `std::begin()`/`std::end()`
 template <return_value_policy Policy = return_value_policy::reference_internal,
-          typename Type, typename... Extra> iterator make_iterator(Type &value, Extra&&... extra) {
+          typename Type,
+          typename... Extra>
+iterator make_iterator(Type &value, Extra &&...extra) {
     return make_iterator<Policy>(std::begin(value), std::end(value), extra...);
 }
 
 /// Makes an iterator over the keys (`.first`) of a stl map-like container supporting
 /// `std::begin()`/`std::end()`
 template <return_value_policy Policy = return_value_policy::reference_internal,
-          typename Type, typename... Extra> iterator make_key_iterator(Type &value, Extra&&... extra) {
+          typename Type,
+          typename... Extra>
+iterator make_key_iterator(Type &value, Extra &&...extra) {
     return make_key_iterator<Policy>(std::begin(value), std::end(value), extra...);
 }
 
 /// Makes an iterator over the values (`.second`) of a stl map-like container supporting
 /// `std::begin()`/`std::end()`
 template <return_value_policy Policy = return_value_policy::reference_internal,
-          typename Type, typename... Extra> iterator make_value_iterator(Type &value, Extra&&... extra) {
+          typename Type,
+          typename... Extra>
+iterator make_value_iterator(Type &value, Extra &&...extra) {
     return make_value_iterator<Policy>(std::begin(value), std::end(value), extra...);
 }
 
-template <typename InputType, typename OutputType> void implicitly_convertible() {
+template <typename InputType, typename OutputType>
+void implicitly_convertible() {
     struct set_flag {
         bool &flag;
         explicit set_flag(bool &flag_) : flag(flag_) { flag_ = true; }
@@ -2202,25 +2409,23 @@ template <typename InputType, typename OutputType> void implicitly_convertible()
         return result;
     };
 
-    if (auto tinfo = detail::get_type_info(typeid(OutputType)))
+    if (auto *tinfo = detail::get_type_info(typeid(OutputType)))
         tinfo->implicit_conversions.push_back(implicit_caster);
     else
         pybind11_fail("implicitly_convertible: Unable to find type " + type_id<OutputType>());
 }
 
-
 inline void register_exception_translator(ExceptionTranslator &&translator) {
     detail::get_internals().registered_exception_translators.push_front(
         std::forward<ExceptionTranslator>(translator));
 }
 
-
 /**
-  * Add a new module-local exception translator. Locally registered functions
-  * will be tried before any globally registered exception translators, which
-  * will only be invoked if the module-local handlers do not deal with
-  * the exception.
-  */
+ * Add a new module-local exception translator. Locally registered functions
+ * will be tried before any globally registered exception translators, which
+ * will only be invoked if the module-local handlers do not deal with
+ * the exception.
+ */
 inline void register_local_exception_translator(ExceptionTranslator &&translator) {
     detail::get_local_internals().registered_exception_translators.push_front(
         std::forward<ExceptionTranslator>(translator));
@@ -2238,19 +2443,18 @@ class exception : public object {
 public:
     exception() = default;
     exception(handle scope, const char *name, handle base = PyExc_Exception) {
-        std::string full_name = scope.attr("__name__").cast<std::string>() +
-                                std::string(".") + name;
+        std::string full_name
+            = scope.attr("__name__").cast<std::string>() + std::string(".") + name;
         m_ptr = PyErr_NewException(const_cast<char *>(full_name.c_str()), base.ptr(), NULL);
         if (hasattr(scope, "__dict__") && scope.attr("__dict__").contains(name))
             pybind11_fail("Error during initialization: multiple incompatible "
-                          "definitions with name \"" + std::string(name) + "\"");
+                          "definitions with name \""
+                          + std::string(name) + "\"");
         scope.attr(name) = *this;
     }
 
     // Sets the current python exception to this exception object with the given message
-    void operator()(const char *message) {
-        PyErr_SetString(m_ptr, message);
-    }
+    void operator()(const char *message) { PyErr_SetString(m_ptr, message); }
 };
 
 PYBIND11_NAMESPACE_BEGIN(detail)
@@ -2258,22 +2462,25 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 // register_exception approach below.  (It would be simpler to have the static local variable
 // directly in register_exception, but that makes clang <3.5 segfault - issue #1349).
 template <typename CppException>
-exception<CppException> &get_exception_object() { static exception<CppException> ex; return ex; }
+exception<CppException> &get_exception_object() {
+    static exception<CppException> ex;
+    return ex;
+}
 
 // Helper function for register_exception and register_local_exception
 template <typename CppException>
-exception<CppException> &register_exception_impl(handle scope,
-                                                const char *name,
-                                                handle base,
-                                                bool isLocal) {
+exception<CppException> &
+register_exception_impl(handle scope, const char *name, handle base, bool isLocal) {
     auto &ex = detail::get_exception_object<CppException>();
-    if (!ex) ex = exception<CppException>(scope, name, base);
+    if (!ex)
+        ex = exception<CppException>(scope, name, base);
 
-    auto register_func = isLocal ? &register_local_exception_translator
-                                 : &register_exception_translator;
+    auto register_func
+        = isLocal ? &register_local_exception_translator : &register_exception_translator;
 
     register_func([](std::exception_ptr p) {
-        if (!p) return;
+        if (!p)
+            return;
         try {
             std::rethrow_exception(p);
         } catch (const CppException &e) {
@@ -2292,9 +2499,8 @@ PYBIND11_NAMESPACE_END(detail)
  * exception object and translator directly.
  */
 template <typename CppException>
-exception<CppException> &register_exception(handle scope,
-                                            const char *name,
-                                            handle base = PyExc_Exception) {
+exception<CppException> &
+register_exception(handle scope, const char *name, handle base = PyExc_Exception) {
     return detail::register_exception_impl<CppException>(scope, name, base, false /* isLocal */);
 }
 
@@ -2307,9 +2513,8 @@ exception<CppException> &register_exception(handle scope,
  * exception object and translator directly.
  */
 template <typename CppException>
-exception<CppException> &register_local_exception(handle scope,
-                                                  const char *name,
-                                                  handle base = PyExc_Exception) {
+exception<CppException> &
+register_local_exception(handle scope, const char *name, handle base = PyExc_Exception) {
     return detail::register_exception_impl<CppException>(scope, name, base, true /* isLocal */);
 }
 
@@ -2363,7 +2568,8 @@ error_already_set::~error_already_set() {
 }
 
 PYBIND11_NAMESPACE_BEGIN(detail)
-inline function get_type_override(const void *this_ptr, const type_info *this_type, const char *name)  {
+inline function
+get_type_override(const void *this_ptr, const type_info *this_type, const char *name) {
     handle self = get_object_handle(this_ptr, this_type);
     if (!self)
         return function();
@@ -2387,17 +2593,16 @@ inline function get_type_override(const void *this_ptr, const type_info *this_ty
 #if !defined(PYPY_VERSION) && PY_VERSION_HEX < 0x030B0000
     // TODO: Remove PyPy workaround for Python 3.11.
     // Current API fails on 3.11 since co_varnames can be null.
-#if PY_VERSION_HEX >= 0x03090000
+#    if PY_VERSION_HEX >= 0x03090000
     PyFrameObject *frame = PyThreadState_GetFrame(PyThreadState_Get());
     if (frame != nullptr) {
         PyCodeObject *f_code = PyFrame_GetCode(frame);
         // f_code is guaranteed to not be NULL
         if ((std::string) str(f_code->co_name) == name && f_code->co_argcount > 0) {
-            PyObject* locals = PyEval_GetLocals();
+            PyObject *locals = PyEval_GetLocals();
             if (locals != nullptr && f_code->co_varnames != nullptr) {
-                PyObject *self_caller = dict_getitem(
-                    locals, PyTuple_GET_ITEM(f_code->co_varnames, 0)
-                );
+                PyObject *self_caller
+                    = dict_getitem(locals, PyTuple_GET_ITEM(f_code->co_varnames, 0));
                 if (self_caller == self.ptr()) {
                     Py_DECREF(f_code);
                     Py_DECREF(frame);
@@ -2408,34 +2613,38 @@ inline function get_type_override(const void *this_ptr, const type_info *this_ty
         Py_DECREF(f_code);
         Py_DECREF(frame);
     }
-#else
+#    else
     PyFrameObject *frame = PyThreadState_Get()->frame;
     if (frame != nullptr && (std::string) str(frame->f_code->co_name) == name
         && frame->f_code->co_argcount > 0) {
         PyFrame_FastToLocals(frame);
-        PyObject *self_caller = dict_getitem(
-            frame->f_locals, PyTuple_GET_ITEM(frame->f_code->co_varnames, 0));
+        PyObject *self_caller
+            = dict_getitem(frame->f_locals, PyTuple_GET_ITEM(frame->f_code->co_varnames, 0));
         if (self_caller == self.ptr())
             return function();
     }
-#endif
+#    endif
 
 #else
     /* PyPy currently doesn't provide a detailed cpyext emulation of
        frame objects, so we have to emulate this using Python. This
        is going to be slow..*/
-    dict d; d["self"] = self; d["name"] = pybind11::str(name);
-    PyObject *result = PyRun_String(
-        "import inspect\n"
-        "frame = inspect.currentframe()\n"
-        "if frame is not None:\n"
-        "    frame = frame.f_back\n"
-        "    if frame is not None and str(frame.f_code.co_name) == name and "
-        "frame.f_code.co_argcount > 0:\n"
-        "        self_caller = frame.f_locals[frame.f_code.co_varnames[0]]\n"
-        "        if self_caller == self:\n"
-        "            self = None\n",
-        Py_file_input, d.ptr(), d.ptr());
+    dict d;
+    d["self"] = self;
+    d["name"] = pybind11::str(name);
+    PyObject *result
+        = PyRun_String("import inspect\n"
+                       "frame = inspect.currentframe()\n"
+                       "if frame is not None:\n"
+                       "    frame = frame.f_back\n"
+                       "    if frame is not None and str(frame.f_code.co_name) == name and "
+                       "frame.f_code.co_argcount > 0:\n"
+                       "        self_caller = frame.f_locals[frame.f_code.co_varnames[0]]\n"
+                       "        if self_caller == self:\n"
+                       "            self = None\n",
+                       Py_file_input,
+                       d.ptr(),
+                       d.ptr());
     if (result == nullptr)
         throw error_already_set();
     if (d["self"].is_none())
@@ -2448,15 +2657,17 @@ inline function get_type_override(const void *this_ptr, const type_info *this_ty
 PYBIND11_NAMESPACE_END(detail)
 
 /** \rst
-  Try to retrieve a python method by the provided name from the instance pointed to by the this_ptr.
+  Try to retrieve a python method by the provided name from the instance pointed to by the
+  this_ptr.
 
-  :this_ptr: The pointer to the object the overridden method should be retrieved for. This should be
-             the first non-trampoline class encountered in the inheritance chain.
+  :this_ptr: The pointer to the object the overridden method should be retrieved for. This should
+             be the first non-trampoline class encountered in the inheritance chain.
   :name: The name of the overridden Python method to retrieve.
   :return: The Python method by this name from the object or an empty function wrapper.
  \endrst */
-template <class T> function get_override(const T *this_ptr, const char *name) {
-    auto tinfo = detail::get_type_info(typeid(T));
+template <class T>
+function get_override(const T *this_ptr, const char *name) {
+    auto *tinfo = detail::get_type_info(typeid(T));
     return tinfo ? detail::get_type_override(this_ptr, tinfo, name) : function();
 }
 
@@ -2476,9 +2687,10 @@ template <class T> function get_override(const T *this_ptr, const char *name) {
     } while (false)
 
 /** \rst
-    Macro to populate the virtual method in the trampoline class. This macro tries to look up a method named 'fn'
-    from the Python side, deals with the :ref:`gil` and necessary argument conversions to call this method and return
-    the appropriate type. See :ref:`overriding_virtuals` for more information. This macro should be used when the method
+    Macro to populate the virtual method in the trampoline class. This macro tries to look up a
+    method named 'fn' from the Python side, deals with the :ref:`gil` and necessary argument
+    conversions to call this method and return the appropriate type.
+    See :ref:`overriding_virtuals` for more information. This macro should be used when the method
     name in C is not the same as the method name in Python. For example with `__str__`.
 
     .. code-block:: cpp
@@ -2492,27 +2704,28 @@ template <class T> function get_override(const T *this_ptr, const char *name) {
         );
       }
 \endrst */
-#define PYBIND11_OVERRIDE_NAME(ret_type, cname, name, fn, ...) \
-    do { \
+#define PYBIND11_OVERRIDE_NAME(ret_type, cname, name, fn, ...)                                    \
+    do {                                                                                          \
         PYBIND11_OVERRIDE_IMPL(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), name, __VA_ARGS__); \
-        return cname::fn(__VA_ARGS__); \
+        return cname::fn(__VA_ARGS__);                                                            \
     } while (false)
 
 /** \rst
-    Macro for pure virtual functions, this function is identical to :c:macro:`PYBIND11_OVERRIDE_NAME`, except that it
-    throws if no override can be found.
+    Macro for pure virtual functions, this function is identical to
+    :c:macro:`PYBIND11_OVERRIDE_NAME`, except that it throws if no override can be found.
 \endrst */
-#define PYBIND11_OVERRIDE_PURE_NAME(ret_type, cname, name, fn, ...) \
-    do { \
+#define PYBIND11_OVERRIDE_PURE_NAME(ret_type, cname, name, fn, ...)                               \
+    do {                                                                                          \
         PYBIND11_OVERRIDE_IMPL(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), name, __VA_ARGS__); \
-        pybind11::pybind11_fail("Tried to call pure virtual function \"" PYBIND11_STRINGIFY(cname) "::" name "\""); \
+        pybind11::pybind11_fail(                                                                  \
+            "Tried to call pure virtual function \"" PYBIND11_STRINGIFY(cname) "::" name "\"");   \
     } while (false)
 
 /** \rst
-    Macro to populate the virtual method in the trampoline class. This macro tries to look up the method
-    from the Python side, deals with the :ref:`gil` and necessary argument conversions to call this method and return
-    the appropriate type. This macro should be used if the method name in C and in Python are identical.
-    See :ref:`overriding_virtuals` for more information.
+    Macro to populate the virtual method in the trampoline class. This macro tries to look up the
+    method from the Python side, deals with the :ref:`gil` and necessary argument conversions to
+    call this method and return the appropriate type. This macro should be used if the method name
+    in C and in Python are identical. See :ref:`overriding_virtuals` for more information.
 
     .. code-block:: cpp
 
@@ -2532,21 +2745,22 @@ template <class T> function get_override(const T *this_ptr, const char *name) {
           }
       };
 \endrst */
-#define PYBIND11_OVERRIDE(ret_type, cname, fn, ...) \
+#define PYBIND11_OVERRIDE(ret_type, cname, fn, ...)                                               \
     PYBIND11_OVERRIDE_NAME(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), #fn, fn, __VA_ARGS__)
 
 /** \rst
-    Macro for pure virtual functions, this function is identical to :c:macro:`PYBIND11_OVERRIDE`, except that it throws
-    if no override can be found.
+    Macro for pure virtual functions, this function is identical to :c:macro:`PYBIND11_OVERRIDE`,
+    except that it throws if no override can be found.
 \endrst */
-#define PYBIND11_OVERRIDE_PURE(ret_type, cname, fn, ...) \
-    PYBIND11_OVERRIDE_PURE_NAME(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), #fn, fn, __VA_ARGS__)
-
+#define PYBIND11_OVERRIDE_PURE(ret_type, cname, fn, ...)                                          \
+    PYBIND11_OVERRIDE_PURE_NAME(                                                                  \
+        PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), #fn, fn, __VA_ARGS__)
 
 // Deprecated versions
 
 PYBIND11_DEPRECATED("get_type_overload has been deprecated")
-inline function get_type_overload(const void *this_ptr, const detail::type_info *this_type, const char *name) {
+inline function
+get_type_overload(const void *this_ptr, const detail::type_info *this_type, const char *name) {
     return detail::get_type_override(this_ptr, this_type, name);
 }
 
@@ -2555,15 +2769,16 @@ inline function get_overload(const T *this_ptr, const char *name) {
     return get_override(this_ptr, name);
 }
 
-#define PYBIND11_OVERLOAD_INT(ret_type, cname, name, ...) \
+#define PYBIND11_OVERLOAD_INT(ret_type, cname, name, ...)                                         \
     PYBIND11_OVERRIDE_IMPL(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), name, __VA_ARGS__)
-#define PYBIND11_OVERLOAD_NAME(ret_type, cname, name, fn, ...) \
+#define PYBIND11_OVERLOAD_NAME(ret_type, cname, name, fn, ...)                                    \
     PYBIND11_OVERRIDE_NAME(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), name, fn, __VA_ARGS__)
-#define PYBIND11_OVERLOAD_PURE_NAME(ret_type, cname, name, fn, ...) \
-    PYBIND11_OVERRIDE_PURE_NAME(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), name, fn, __VA_ARGS__);
-#define PYBIND11_OVERLOAD(ret_type, cname, fn, ...) \
+#define PYBIND11_OVERLOAD_PURE_NAME(ret_type, cname, name, fn, ...)                               \
+    PYBIND11_OVERRIDE_PURE_NAME(                                                                  \
+        PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), name, fn, __VA_ARGS__);
+#define PYBIND11_OVERLOAD(ret_type, cname, fn, ...)                                               \
     PYBIND11_OVERRIDE(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), fn, __VA_ARGS__)
-#define PYBIND11_OVERLOAD_PURE(ret_type, cname, fn, ...) \
+#define PYBIND11_OVERLOAD_PURE(ret_type, cname, fn, ...)                                          \
     PYBIND11_OVERRIDE_PURE(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), fn, __VA_ARGS__);
 
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
diff --git a/include/pybind11/pytypes.h b/include/pybind11/pytypes.h
index 902fb1f07d..f9ab75eba9 100644
--- a/include/pybind11/pytypes.h
+++ b/include/pybind11/pytypes.h
@@ -11,38 +11,43 @@
 
 #include "detail/common.h"
 #include "buffer_info.h"
-#include <utility>
+
 #include <type_traits>
+#include <utility>
 
 #if defined(PYBIND11_HAS_OPTIONAL)
-#  include <optional>
+#    include <optional>
 #endif
 
 #ifdef PYBIND11_HAS_STRING_VIEW
-#  include <string_view>
+#    include <string_view>
 #endif
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 
 /* A few forward declarations */
-class handle; class object;
-class str; class iterator;
+class handle;
+class object;
+class str;
+class iterator;
 class type;
-struct arg; struct arg_v;
+struct arg;
+struct arg_v;
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 class args_proxy;
 bool isinstance_generic(handle obj, const std::type_info &tp);
 
 // Accessor forward declarations
-template <typename Policy> class accessor;
+template <typename Policy>
+class accessor;
 namespace accessor_policies {
-    struct obj_attr;
-    struct str_attr;
-    struct generic_item;
-    struct sequence_item;
-    struct list_item;
-    struct tuple_item;
+struct obj_attr;
+struct str_attr;
+struct generic_item;
+struct sequence_item;
+struct list_item;
+struct tuple_item;
 } // namespace accessor_policies
 using obj_attr_accessor = accessor<accessor_policies::obj_attr>;
 using str_attr_accessor = accessor<accessor_policies::str_attr>;
@@ -52,8 +57,9 @@ using list_accessor = accessor<accessor_policies::list_item>;
 using tuple_accessor = accessor<accessor_policies::tuple_item>;
 
 /// Tag and check to identify a class which implements the Python object API
-class pyobject_tag { };
-template <typename T> using is_pyobject = std::is_base_of<pyobject_tag, remove_reference_t<T>>;
+class pyobject_tag {};
+template <typename T>
+using is_pyobject = std::is_base_of<pyobject_tag, remove_reference_t<T>>;
 
 /** \rst
     A mixin class which adds common functions to `handle`, `object` and various accessors.
@@ -101,7 +107,8 @@ class object_api : public pyobject_tag {
     args_proxy operator*() const;
 
     /// Check if the given item is contained within this object, i.e. ``item in obj``.
-    template <typename T> bool contains(T &&item) const;
+    template <typename T>
+    bool contains(T &&item) const;
 
     /** \rst
         Assuming the Python object is a function or implements the ``__call__``
@@ -113,22 +120,24 @@ class object_api : public pyobject_tag {
         function will throw a `cast_error` exception. When the Python function
         call fails, a `error_already_set` exception is thrown.
     \endrst */
-    template <return_value_policy policy = return_value_policy::automatic_reference, typename... Args>
+    template <return_value_policy policy = return_value_policy::automatic_reference,
+              typename... Args>
     object operator()(Args &&...args) const;
-    template <return_value_policy policy = return_value_policy::automatic_reference, typename... Args>
+    template <return_value_policy policy = return_value_policy::automatic_reference,
+              typename... Args>
     PYBIND11_DEPRECATED("call(...) was deprecated in favor of operator()(...)")
-        object call(Args&&... args) const;
+    object call(Args &&...args) const;
 
     /// Equivalent to ``obj is other`` in Python.
-    bool is(object_api const& other) const { return derived().ptr() == other.derived().ptr(); }
+    bool is(object_api const &other) const { return derived().ptr() == other.derived().ptr(); }
     /// Equivalent to ``obj is None`` in Python.
     bool is_none() const { return derived().ptr() == Py_None; }
     /// Equivalent to obj == other in Python
-    bool equal(object_api const &other) const      { return rich_compare(other, Py_EQ); }
-    bool not_equal(object_api const &other) const  { return rich_compare(other, Py_NE); }
-    bool operator<(object_api const &other) const  { return rich_compare(other, Py_LT); }
+    bool equal(object_api const &other) const { return rich_compare(other, Py_EQ); }
+    bool not_equal(object_api const &other) const { return rich_compare(other, Py_NE); }
+    bool operator<(object_api const &other) const { return rich_compare(other, Py_LT); }
     bool operator<=(object_api const &other) const { return rich_compare(other, Py_LE); }
-    bool operator>(object_api const &other) const  { return rich_compare(other, Py_GT); }
+    bool operator>(object_api const &other) const { return rich_compare(other, Py_GT); }
     bool operator>=(object_api const &other) const { return rich_compare(other, Py_GE); }
 
     object operator-() const;
@@ -161,7 +170,8 @@ class object_api : public pyobject_tag {
     /// Return the object's current reference count
     int ref_count() const { return static_cast<int>(Py_REFCNT(derived().ptr())); }
 
-    // TODO PYBIND11_DEPRECATED("Call py::type::handle_of(h) or py::type::of(h) instead of h.get_type()")
+    // TODO PYBIND11_DEPRECATED("Call py::type::handle_of(h) or py::type::of(h) instead of
+    // h.get_type()")
     handle get_type() const;
 
 private:
@@ -187,7 +197,7 @@ class handle : public detail::object_api<handle> {
     handle() = default;
     /// Creates a ``handle`` from the given raw Python object pointer
     // NOLINTNEXTLINE(google-explicit-constructor)
-    handle(PyObject *ptr) : m_ptr(ptr) { } // Allow implicit conversion from PyObject*
+    handle(PyObject *ptr) : m_ptr(ptr) {} // Allow implicit conversion from PyObject*
 
     /// Return the underlying ``PyObject *`` pointer
     PyObject *ptr() const { return m_ptr; }
@@ -198,20 +208,27 @@ class handle : public detail::object_api<handle> {
         preferable to use the `object` class which derives from `handle` and calls
         this function automatically. Returns a reference to itself.
     \endrst */
-    const handle& inc_ref() const & { Py_XINCREF(m_ptr); return *this; }
+    const handle &inc_ref() const & {
+        Py_XINCREF(m_ptr);
+        return *this;
+    }
 
     /** \rst
         Manually decrease the reference count of the Python object. Usually, it is
         preferable to use the `object` class which derives from `handle` and calls
         this function automatically. Returns a reference to itself.
     \endrst */
-    const handle& dec_ref() const & { Py_XDECREF(m_ptr); return *this; }
+    const handle &dec_ref() const & {
+        Py_XDECREF(m_ptr);
+        return *this;
+    }
 
     /** \rst
         Attempt to cast the Python object into the given C++ type. A `cast_error`
         will be throw upon failure.
     \endrst */
-    template <typename T> T cast() const;
+    template <typename T>
+    T cast() const;
     /// Return ``true`` when the `handle` wraps a valid Python object
     explicit operator bool() const { return m_ptr != nullptr; }
     /** \rst
@@ -224,6 +241,7 @@ class handle : public detail::object_api<handle> {
     bool operator!=(const handle &h) const { return m_ptr != h.m_ptr; }
     PYBIND11_DEPRECATED("Use handle::operator bool() instead")
     bool check() const { return m_ptr != nullptr; }
+
 protected:
     PyObject *m_ptr = nullptr;
 };
@@ -242,11 +260,17 @@ class object : public handle {
 public:
     object() = default;
     PYBIND11_DEPRECATED("Use reinterpret_borrow<object>() or reinterpret_steal<object>()")
-    object(handle h, bool is_borrowed) : handle(h) { if (is_borrowed) inc_ref(); }
+    object(handle h, bool is_borrowed) : handle(h) {
+        if (is_borrowed)
+            inc_ref();
+    }
     /// Copy constructor; always increases the reference count
     object(const object &o) : handle(o) { inc_ref(); }
     /// Move constructor; steals the object from ``other`` and preserves its reference count
-    object(object &&other) noexcept { m_ptr = other.m_ptr; other.m_ptr = nullptr; }
+    object(object &&other) noexcept {
+        m_ptr = other.m_ptr;
+        other.m_ptr = nullptr;
+    }
     /// Destructor; automatically calls `handle::dec_ref()`
     ~object() { dec_ref(); }
 
@@ -256,12 +280,12 @@ class object : public handle {
         Python object.
     \endrst */
     handle release() {
-      PyObject *tmp = m_ptr;
-      m_ptr = nullptr;
-      return handle(tmp);
+        PyObject *tmp = m_ptr;
+        m_ptr = nullptr;
+        return handle(tmp);
     }
 
-    object& operator=(const object &other) {
+    object &operator=(const object &other) {
         other.inc_ref();
         // Use temporary variable to ensure `*this` remains valid while
         // `Py_XDECREF` executes, in case `*this` is accessible from Python.
@@ -271,7 +295,7 @@ class object : public handle {
         return *this;
     }
 
-    object& operator=(object &&other) noexcept {
+    object &operator=(object &&other) noexcept {
         if (this != &other) {
             handle temp(m_ptr);
             m_ptr = other.m_ptr;
@@ -282,24 +306,28 @@ class object : public handle {
     }
 
     // Calling cast() on an object lvalue just copies (via handle::cast)
-    template <typename T> T cast() const &;
+    template <typename T>
+    T cast() const &;
     // Calling on an object rvalue does a move, if needed and/or possible
-    template <typename T> T cast() &&;
+    template <typename T>
+    T cast() &&;
 
 protected:
     // Tags for choosing constructors from raw PyObject *
-    struct borrowed_t { };
-    struct stolen_t { };
+    struct borrowed_t {};
+    struct stolen_t {};
 
     /// @cond BROKEN
-    template <typename T> friend T reinterpret_borrow(handle);
-    template <typename T> friend T reinterpret_steal(handle);
+    template <typename T>
+    friend T reinterpret_borrow(handle);
+    template <typename T>
+    friend T reinterpret_steal(handle);
     /// @endcond
 
 public:
     // Only accessible from derived classes and the reinterpret_* functions
     object(handle h, borrowed_t) : handle(h) { inc_ref(); }
-    object(handle h, stolen_t) : handle(h) { }
+    object(handle h, stolen_t) : handle(h) {}
 };
 
 /** \rst
@@ -315,7 +343,10 @@ class object : public handle {
         // or
         py::tuple t = reinterpret_borrow<py::tuple>(p); // <-- `p` must be already be a `tuple`
 \endrst */
-template <typename T> T reinterpret_borrow(handle h) { return {h, object::borrowed_t{}}; }
+template <typename T>
+T reinterpret_borrow(handle h) {
+    return {h, object::borrowed_t{}};
+}
 
 /** \rst
     Like `reinterpret_borrow`, but steals the reference.
@@ -325,15 +356,20 @@ template <typename T> T reinterpret_borrow(handle h) { return {h, object::borrow
         PyObject *p = PyObject_Str(obj);
         py::str s = reinterpret_steal<py::str>(p); // <-- `p` must be already be a `str`
 \endrst */
-template <typename T> T reinterpret_steal(handle h) { return {h, object::stolen_t{}}; }
+template <typename T>
+T reinterpret_steal(handle h) {
+    return {h, object::stolen_t{}};
+}
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 std::string error_string();
 PYBIND11_NAMESPACE_END(detail)
 
 #if defined(_MSC_VER)
-#  pragma warning(push)
-#  pragma warning(disable: 4275 4251) // warning C4275: An exported class was derived from a class that wasn't exported. Can be ignored when derived from a STL class.
+#    pragma warning(push)
+#    pragma warning(disable : 4275 4251)
+//       warning C4275: An exported class was derived from a class that wasn't exported.
+//       Can be ignored when derived from a STL class.
 #endif
 /// Fetch and hold an error which was already set in Python.  An instance of this is typically
 /// thrown to propagate python-side errors back through C++ which can either be caught manually or
@@ -355,19 +391,22 @@ class PYBIND11_EXPORT_EXCEPTION error_already_set : public std::runtime_error {
     /// Give the currently-held error back to Python, if any.  If there is currently a Python error
     /// already set it is cleared first.  After this call, the current object no longer stores the
     /// error variables (but the `.what()` string is still available).
-    void restore() { PyErr_Restore(m_type.release().ptr(), m_value.release().ptr(), m_trace.release().ptr()); }
+    void restore() {
+        PyErr_Restore(m_type.release().ptr(), m_value.release().ptr(), m_trace.release().ptr());
+    }
 
-    /// If it is impossible to raise the currently-held error, such as in a destructor, we can write
-    /// it out using Python's unraisable hook (`sys.unraisablehook`). The error context should be
-    /// some object whose `repr()` helps identify the location of the error. Python already knows the
-    /// type and value of the error, so there is no need to repeat that. After this call, the current
-    /// object no longer stores the error variables, and neither does Python.
+    /// If it is impossible to raise the currently-held error, such as in a destructor, we can
+    /// write it out using Python's unraisable hook (`sys.unraisablehook`). The error context
+    /// should be some object whose `repr()` helps identify the location of the error. Python
+    /// already knows the type and value of the error, so there is no need to repeat that. After
+    /// this call, the current object no longer stores the error variables, and neither does
+    /// Python.
     void discard_as_unraisable(object err_context) {
         restore();
         PyErr_WriteUnraisable(err_context.ptr());
     }
-    /// An alternate version of `discard_as_unraisable()`, where a string provides information on the
-    /// location of the error. For example, `__func__` could be helpful.
+    /// An alternate version of `discard_as_unraisable()`, where a string provides information on
+    /// the location of the error. For example, `__func__` could be helpful.
     void discard_as_unraisable(const char *err_context) {
         discard_as_unraisable(reinterpret_steal<object>(PYBIND11_FROM_STRING(err_context)));
     }
@@ -383,15 +422,15 @@ class PYBIND11_EXPORT_EXCEPTION error_already_set : public std::runtime_error {
         return (PyErr_GivenExceptionMatches(m_type.ptr(), exc.ptr()) != 0);
     }
 
-    const object& type() const { return m_type; }
-    const object& value() const { return m_value; }
-    const object& trace() const { return m_trace; }
+    const object &type() const { return m_type; }
+    const object &value() const { return m_value; }
+    const object &trace() const { return m_trace; }
 
 private:
     object m_type, m_value, m_trace;
 };
 #if defined(_MSC_VER)
-#  pragma warning(pop)
+#    pragma warning(pop)
 #endif
 
 #if PY_VERSION_HEX >= 0x03030000
@@ -428,7 +467,7 @@ inline void raise_from(PyObject *type, const char *message) {
 /// from the error contained in error_already_set to indicate that the chosen error was
 /// caused by the original error. After this function is called error_already_set will
 /// no longer contain an error.
-inline void raise_from(error_already_set& err, PyObject *type, const char *message) {
+inline void raise_from(error_already_set &err, PyObject *type, const char *message) {
     err.restore();
     raise_from(type, message);
 }
@@ -446,13 +485,21 @@ inline void raise_from(error_already_set& err, PyObject *type, const char *messa
     `object` or a class which was exposed to Python as ``py::class_<T>``.
 \endrst */
 template <typename T, detail::enable_if_t<std::is_base_of<object, T>::value, int> = 0>
-bool isinstance(handle obj) { return T::check_(obj); }
+bool isinstance(handle obj) {
+    return T::check_(obj);
+}
 
 template <typename T, detail::enable_if_t<!std::is_base_of<object, T>::value, int> = 0>
-bool isinstance(handle obj) { return detail::isinstance_generic(obj, typeid(T)); }
+bool isinstance(handle obj) {
+    return detail::isinstance_generic(obj, typeid(T));
+}
 
-template <> inline bool isinstance<handle>(handle) = delete;
-template <> inline bool isinstance<object>(handle obj) { return obj.ptr() != nullptr; }
+template <>
+inline bool isinstance<handle>(handle) = delete;
+template <>
+inline bool isinstance<object>(handle obj) {
+    return obj.ptr() != nullptr;
+}
 
 /// \ingroup python_builtins
 /// Return true if ``obj`` is an instance of the ``type``.
@@ -474,22 +521,30 @@ inline bool hasattr(handle obj, const char *name) {
 }
 
 inline void delattr(handle obj, handle name) {
-    if (PyObject_DelAttr(obj.ptr(), name.ptr()) != 0) { throw error_already_set(); }
+    if (PyObject_DelAttr(obj.ptr(), name.ptr()) != 0) {
+        throw error_already_set();
+    }
 }
 
 inline void delattr(handle obj, const char *name) {
-    if (PyObject_DelAttrString(obj.ptr(), name) != 0) { throw error_already_set(); }
+    if (PyObject_DelAttrString(obj.ptr(), name) != 0) {
+        throw error_already_set();
+    }
 }
 
 inline object getattr(handle obj, handle name) {
     PyObject *result = PyObject_GetAttr(obj.ptr(), name.ptr());
-    if (!result) { throw error_already_set(); }
+    if (!result) {
+        throw error_already_set();
+    }
     return reinterpret_steal<object>(result);
 }
 
 inline object getattr(handle obj, const char *name) {
     PyObject *result = PyObject_GetAttrString(obj.ptr(), name);
-    if (!result) { throw error_already_set(); }
+    if (!result) {
+        throw error_already_set();
+    }
     return reinterpret_steal<object>(result);
 }
 
@@ -510,16 +565,22 @@ inline object getattr(handle obj, const char *name, handle default_) {
 }
 
 inline void setattr(handle obj, handle name, handle value) {
-    if (PyObject_SetAttr(obj.ptr(), name.ptr(), value.ptr()) != 0) { throw error_already_set(); }
+    if (PyObject_SetAttr(obj.ptr(), name.ptr(), value.ptr()) != 0) {
+        throw error_already_set();
+    }
 }
 
 inline void setattr(handle obj, const char *name, handle value) {
-    if (PyObject_SetAttrString(obj.ptr(), name, value.ptr()) != 0) { throw error_already_set(); }
+    if (PyObject_SetAttrString(obj.ptr(), name, value.ptr()) != 0) {
+        throw error_already_set();
+    }
 }
 
 inline ssize_t hash(handle obj) {
     auto h = PyObject_Hash(obj.ptr());
-    if (h == -1) { throw error_already_set(); }
+    if (h == -1) {
+        throw error_already_set();
+    }
     return h;
 }
 
@@ -533,7 +594,7 @@ inline handle get_function(handle value) {
             value = PyInstanceMethod_GET_FUNCTION(value.ptr());
         else
 #endif
-        if (PyMethod_Check(value.ptr()))
+            if (PyMethod_Check(value.ptr()))
             value = PyMethod_GET_FUNCTION(value.ptr());
     }
     return value;
@@ -543,8 +604,7 @@ inline handle get_function(handle value) {
 // aren't swallowed (see #2862)
 
 // copied from cpython _PyDict_GetItemStringWithError
-inline PyObject * dict_getitemstring(PyObject *v, const char *key)
-{
+inline PyObject *dict_getitemstring(PyObject *v, const char *key) {
 #if PY_MAJOR_VERSION >= 3
     PyObject *kv = nullptr, *rv = nullptr;
     kv = PyUnicode_FromString(key);
@@ -563,8 +623,7 @@ inline PyObject * dict_getitemstring(PyObject *v, const char *key)
 #endif
 }
 
-inline PyObject * dict_getitem(PyObject *v, PyObject *key)
-{
+inline PyObject *dict_getitem(PyObject *v, PyObject *key) {
 #if PY_MAJOR_VERSION >= 3
     PyObject *rv = PyDict_GetItemWithError(v, key);
     if (rv == NULL && PyErr_Occurred()) {
@@ -576,11 +635,13 @@ inline PyObject * dict_getitem(PyObject *v, PyObject *key)
 #endif
 }
 
-// Helper aliases/functions to support implicit casting of values given to python accessors/methods.
-// When given a pyobject, this simply returns the pyobject as-is; for other C++ type, the value goes
-// through pybind11::cast(obj) to convert it to an `object`.
+// Helper aliases/functions to support implicit casting of values given to python
+// accessors/methods. When given a pyobject, this simply returns the pyobject as-is; for other C++
+// type, the value goes through pybind11::cast(obj) to convert it to an `object`.
 template <typename T, enable_if_t<is_pyobject<T>::value, int> = 0>
-auto object_or_cast(T &&o) -> decltype(std::forward<T>(o)) { return std::forward<T>(o); }
+auto object_or_cast(T &&o) -> decltype(std::forward<T>(o)) {
+    return std::forward<T>(o);
+}
 // The following casting version is implemented in cast.h:
 template <typename T, enable_if_t<!is_pyobject<T>::value, int> = 0>
 object object_or_cast(T &&o);
@@ -588,50 +649,61 @@ object object_or_cast(T &&o);
 inline handle object_or_cast(PyObject *ptr) { return ptr; }
 
 #if defined(_MSC_VER) && _MSC_VER < 1920
-#  pragma warning(push)
-#  pragma warning(disable: 4522) // warning C4522: multiple assignment operators specified
+#    pragma warning(push)
+#    pragma warning(disable : 4522) // warning C4522: multiple assignment operators specified
 #endif
 template <typename Policy>
 class accessor : public object_api<accessor<Policy>> {
     using key_type = typename Policy::key_type;
 
 public:
-    accessor(handle obj, key_type key) : obj(obj), key(std::move(key)) { }
+    accessor(handle obj, key_type key) : obj(obj), key(std::move(key)) {}
     accessor(const accessor &) = default;
     accessor(accessor &&) noexcept = default;
 
-    // accessor overload required to override default assignment operator (templates are not allowed
-    // to replace default compiler-generated assignments).
+    // accessor overload required to override default assignment operator (templates are not
+    // allowed to replace default compiler-generated assignments).
     void operator=(const accessor &a) && { std::move(*this).operator=(handle(a)); }
     void operator=(const accessor &a) & { operator=(handle(a)); }
 
-    template <typename T> void operator=(T &&value) && {
+    template <typename T>
+    void operator=(T &&value) && {
         Policy::set(obj, key, object_or_cast(std::forward<T>(value)));
     }
-    template <typename T> void operator=(T &&value) & {
+    template <typename T>
+    void operator=(T &&value) & {
         get_cache() = reinterpret_borrow<object>(object_or_cast(std::forward<T>(value)));
     }
 
     template <typename T = Policy>
-    PYBIND11_DEPRECATED("Use of obj.attr(...) as bool is deprecated in favor of pybind11::hasattr(obj, ...)")
-    explicit operator enable_if_t<std::is_same<T, accessor_policies::str_attr>::value ||
-            std::is_same<T, accessor_policies::obj_attr>::value, bool>() const {
+    PYBIND11_DEPRECATED(
+        "Use of obj.attr(...) as bool is deprecated in favor of pybind11::hasattr(obj, ...)")
+    explicit
+    operator enable_if_t<std::is_same<T, accessor_policies::str_attr>::value
+                             || std::is_same<T, accessor_policies::obj_attr>::value,
+                         bool>() const {
         return hasattr(obj, key);
     }
     template <typename T = Policy>
     PYBIND11_DEPRECATED("Use of obj[key] as bool is deprecated in favor of obj.contains(key)")
-    explicit operator enable_if_t<std::is_same<T, accessor_policies::generic_item>::value, bool>() const {
+    explicit
+    operator enable_if_t<std::is_same<T, accessor_policies::generic_item>::value, bool>() const {
         return obj.contains(key);
     }
 
     // NOLINTNEXTLINE(google-explicit-constructor)
     operator object() const { return get_cache(); }
     PyObject *ptr() const { return get_cache().ptr(); }
-    template <typename T> T cast() const { return get_cache().template cast<T>(); }
+    template <typename T>
+    T cast() const {
+        return get_cache().template cast<T>();
+    }
 
 private:
     object &get_cache() const {
-        if (!cache) { cache = Policy::get(obj, key); }
+        if (!cache) {
+            cache = Policy::get(obj, key);
+        }
         return cache;
     }
 
@@ -641,7 +713,7 @@ class accessor : public object_api<accessor<Policy>> {
     mutable object cache;
 };
 #if defined(_MSC_VER) && _MSC_VER < 1920
-#  pragma warning(pop)
+#    pragma warning(pop)
 #endif
 
 PYBIND11_NAMESPACE_BEGIN(accessor_policies)
@@ -662,12 +734,16 @@ struct generic_item {
 
     static object get(handle obj, handle key) {
         PyObject *result = PyObject_GetItem(obj.ptr(), key.ptr());
-        if (!result) { throw error_already_set(); }
+        if (!result) {
+            throw error_already_set();
+        }
         return reinterpret_steal<object>(result);
     }
 
     static void set(handle obj, handle key, handle val) {
-        if (PyObject_SetItem(obj.ptr(), key.ptr(), val.ptr()) != 0) { throw error_already_set(); }
+        if (PyObject_SetItem(obj.ptr(), key.ptr(), val.ptr()) != 0) {
+            throw error_already_set();
+        }
     }
 };
 
@@ -677,7 +753,9 @@ struct sequence_item {
     template <typename IdxType, detail::enable_if_t<std::is_integral<IdxType>::value, int> = 0>
     static object get(handle obj, const IdxType &index) {
         PyObject *result = PySequence_GetItem(obj.ptr(), ssize_t_cast(index));
-        if (!result) { throw error_already_set(); }
+        if (!result) {
+            throw error_already_set();
+        }
         return reinterpret_steal<object>(result);
     }
 
@@ -696,7 +774,9 @@ struct list_item {
     template <typename IdxType, detail::enable_if_t<std::is_integral<IdxType>::value, int> = 0>
     static object get(handle obj, const IdxType &index) {
         PyObject *result = PyList_GetItem(obj.ptr(), ssize_t_cast(index));
-        if (!result) { throw error_already_set(); }
+        if (!result) {
+            throw error_already_set();
+        }
         return reinterpret_borrow<object>(result);
     }
 
@@ -715,7 +795,9 @@ struct tuple_item {
     template <typename IdxType, detail::enable_if_t<std::is_integral<IdxType>::value, int> = 0>
     static object get(handle obj, const IdxType &index) {
         PyObject *result = PyTuple_GetItem(obj.ptr(), ssize_t_cast(index));
-        if (!result) { throw error_already_set(); }
+        if (!result) {
+            throw error_already_set();
+        }
         return reinterpret_borrow<object>(result);
     }
 
@@ -742,7 +824,7 @@ class generic_iterator : public Policy {
     using pointer = typename Policy::pointer;
 
     generic_iterator() = default;
-    generic_iterator(handle seq, ssize_t index) : Policy(seq, index) { }
+    generic_iterator(handle seq, ssize_t index) : Policy(seq, index) {}
 
     // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
     reference operator*() const { return Policy::dereference(); }
@@ -750,22 +832,48 @@ class generic_iterator : public Policy {
     reference operator[](difference_type n) const { return *(*this + n); }
     pointer operator->() const { return **this; }
 
-    It &operator++() { Policy::increment(); return *this; }
-    It operator++(int) { auto copy = *this; Policy::increment(); return copy; }
-    It &operator--() { Policy::decrement(); return *this; }
-    It operator--(int) { auto copy = *this; Policy::decrement(); return copy; }
-    It &operator+=(difference_type n) { Policy::advance(n); return *this; }
-    It &operator-=(difference_type n) { Policy::advance(-n); return *this; }
+    It &operator++() {
+        Policy::increment();
+        return *this;
+    }
+    It operator++(int) {
+        auto copy = *this;
+        Policy::increment();
+        return copy;
+    }
+    It &operator--() {
+        Policy::decrement();
+        return *this;
+    }
+    It operator--(int) {
+        auto copy = *this;
+        Policy::decrement();
+        return copy;
+    }
+    It &operator+=(difference_type n) {
+        Policy::advance(n);
+        return *this;
+    }
+    It &operator-=(difference_type n) {
+        Policy::advance(-n);
+        return *this;
+    }
 
-    friend It operator+(const It &a, difference_type n) { auto copy = a; return copy += n; }
+    friend It operator+(const It &a, difference_type n) {
+        auto copy = a;
+        return copy += n;
+    }
     friend It operator+(difference_type n, const It &b) { return b + n; }
-    friend It operator-(const It &a, difference_type n) { auto copy = a; return copy -= n; }
+    friend It operator-(const It &a, difference_type n) {
+        auto copy = a;
+        return copy -= n;
+    }
     friend difference_type operator-(const It &a, const It &b) { return a.distance_to(b); }
 
     friend bool operator==(const It &a, const It &b) { return a.equal(b); }
     friend bool operator!=(const It &a, const It &b) { return !(a == b); }
-    friend bool operator< (const It &a, const It &b) { return b - a > 0; }
-    friend bool operator> (const It &a, const It &b) { return b < a; }
+    friend bool operator<(const It &a, const It &b) { return b - a > 0; }
+    friend bool operator>(const It &a, const It &b) { return b < a; }
     friend bool operator>=(const It &a, const It &b) { return !(a < b); }
     friend bool operator<=(const It &a, const It &b) { return !(a > b); }
 };
@@ -777,7 +885,7 @@ struct arrow_proxy {
     T value;
 
     // NOLINTNEXTLINE(google-explicit-constructor)
-    arrow_proxy(T &&value) noexcept : value(std::move(value)) { }
+    arrow_proxy(T &&value) noexcept : value(std::move(value)) {}
     T *operator->() const { return &value; }
 };
 
@@ -789,7 +897,7 @@ class sequence_fast_readonly {
     using reference = const handle; // PR #3263
     using pointer = arrow_proxy<const handle>;
 
-    sequence_fast_readonly(handle obj, ssize_t n) : ptr(PySequence_Fast_ITEMS(obj.ptr()) + n) { }
+    sequence_fast_readonly(handle obj, ssize_t n) : ptr(PySequence_Fast_ITEMS(obj.ptr()) + n) {}
 
     // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
     reference dereference() const { return *ptr; }
@@ -811,7 +919,7 @@ class sequence_slow_readwrite {
     using reference = sequence_accessor;
     using pointer = arrow_proxy<const sequence_accessor>;
 
-    sequence_slow_readwrite(handle obj, ssize_t index) : obj(obj), index(index) { }
+    sequence_slow_readwrite(handle obj, ssize_t index) : obj(obj), index(index) {}
 
     reference dereference() const { return {obj, static_cast<size_t>(index)}; }
     void increment() { ++index; }
@@ -877,33 +985,38 @@ inline bool PyNone_Check(PyObject *o) { return o == Py_None; }
 inline bool PyEllipsis_Check(PyObject *o) { return o == Py_Ellipsis; }
 
 #ifdef PYBIND11_STR_LEGACY_PERMISSIVE
-inline bool PyUnicode_Check_Permissive(PyObject *o) { return PyUnicode_Check(o) || PYBIND11_BYTES_CHECK(o); }
-#define PYBIND11_STR_CHECK_FUN detail::PyUnicode_Check_Permissive
+inline bool PyUnicode_Check_Permissive(PyObject *o) {
+    return PyUnicode_Check(o) || PYBIND11_BYTES_CHECK(o);
+}
+#    define PYBIND11_STR_CHECK_FUN detail::PyUnicode_Check_Permissive
 #else
-#define PYBIND11_STR_CHECK_FUN PyUnicode_Check
+#    define PYBIND11_STR_CHECK_FUN PyUnicode_Check
 #endif
 
 inline bool PyStaticMethod_Check(PyObject *o) { return o->ob_type == &PyStaticMethod_Type; }
 
 class kwargs_proxy : public handle {
 public:
-    explicit kwargs_proxy(handle h) : handle(h) { }
+    explicit kwargs_proxy(handle h) : handle(h) {}
 };
 
 class args_proxy : public handle {
 public:
-    explicit args_proxy(handle h) : handle(h) { }
+    explicit args_proxy(handle h) : handle(h) {}
     kwargs_proxy operator*() const { return kwargs_proxy(*this); }
 };
 
 /// Python argument categories (using PEP 448 terms)
-template <typename T> using is_keyword = std::is_base_of<arg, T>;
-template <typename T> using is_s_unpacking = std::is_same<args_proxy, T>; // * unpacking
-template <typename T> using is_ds_unpacking = std::is_same<kwargs_proxy, T>; // ** unpacking
-template <typename T> using is_positional = satisfies_none_of<T,
-    is_keyword, is_s_unpacking, is_ds_unpacking
->;
-template <typename T> using is_keyword_or_ds = satisfies_any_of<T, is_keyword, is_ds_unpacking>;
+template <typename T>
+using is_keyword = std::is_base_of<arg, T>;
+template <typename T>
+using is_s_unpacking = std::is_same<args_proxy, T>; // * unpacking
+template <typename T>
+using is_ds_unpacking = std::is_same<kwargs_proxy, T>; // ** unpacking
+template <typename T>
+using is_positional = satisfies_none_of<T, is_keyword, is_s_unpacking, is_ds_unpacking>;
+template <typename T>
+using is_keyword_or_ds = satisfies_any_of<T, is_keyword, is_ds_unpacking>;
 
 // Call argument collector forward declarations
 template <return_value_policy policy = return_value_policy::automatic_reference>
@@ -917,53 +1030,60 @@ PYBIND11_NAMESPACE_END(detail)
 //       inheriting ctors: `using Parent::Parent`. It's not an option right now because
 //       the `using` statement triggers the parent deprecation warning even if the ctor
 //       isn't even used.
-#define PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun) \
-    public: \
-        PYBIND11_DEPRECATED("Use reinterpret_borrow<"#Name">() or reinterpret_steal<"#Name">()") \
-        Name(handle h, bool is_borrowed) : Parent(is_borrowed ? Parent(h, borrowed_t{}) : Parent(h, stolen_t{})) { } \
-        Name(handle h, borrowed_t) : Parent(h, borrowed_t{}) { } \
-        Name(handle h, stolen_t) : Parent(h, stolen_t{}) { } \
-        PYBIND11_DEPRECATED("Use py::isinstance<py::python_type>(obj) instead") \
-        bool check() const { return m_ptr != nullptr && (CheckFun(m_ptr) != 0); } \
-        static bool check_(handle h) { return h.ptr() != nullptr && CheckFun(h.ptr()); } \
-        template <typename Policy_> \
-        /* NOLINTNEXTLINE(google-explicit-constructor) */ \
-        Name(const ::pybind11::detail::accessor<Policy_> &a) : Name(object(a)) { }
-
-#define PYBIND11_OBJECT_CVT(Name, Parent, CheckFun, ConvertFun) \
-    PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun) \
-    /* This is deliberately not 'explicit' to allow implicit conversion from object: */ \
-    /* NOLINTNEXTLINE(google-explicit-constructor) */ \
-    Name(const object &o) \
-    : Parent(check_(o) ? o.inc_ref().ptr() : ConvertFun(o.ptr()), stolen_t{}) \
-    { if (!m_ptr) throw error_already_set(); } \
-    /* NOLINTNEXTLINE(google-explicit-constructor) */ \
-    Name(object &&o) \
-    : Parent(check_(o) ? o.release().ptr() : ConvertFun(o.ptr()), stolen_t{}) \
-    { if (!m_ptr) throw error_already_set(); }
-
-#define PYBIND11_OBJECT_CVT_DEFAULT(Name, Parent, CheckFun, ConvertFun) \
-    PYBIND11_OBJECT_CVT(Name, Parent, CheckFun, ConvertFun) \
-    Name() : Parent() { }
-
-#define PYBIND11_OBJECT_CHECK_FAILED(Name, o_ptr) \
-    ::pybind11::type_error("Object of type '" + \
-                           ::pybind11::detail::get_fully_qualified_tp_name(Py_TYPE(o_ptr)) + \
-                           "' is not an instance of '" #Name "'")
-
-#define PYBIND11_OBJECT(Name, Parent, CheckFun) \
-    PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun) \
-    /* This is deliberately not 'explicit' to allow implicit conversion from object: */ \
-    /* NOLINTNEXTLINE(google-explicit-constructor) */ \
-    Name(const object &o) : Parent(o) \
-    { if (m_ptr && !check_(m_ptr)) throw PYBIND11_OBJECT_CHECK_FAILED(Name, m_ptr); } \
-    /* NOLINTNEXTLINE(google-explicit-constructor) */ \
-    Name(object &&o) : Parent(std::move(o)) \
-    { if (m_ptr && !check_(m_ptr)) throw PYBIND11_OBJECT_CHECK_FAILED(Name, m_ptr); }
-
-#define PYBIND11_OBJECT_DEFAULT(Name, Parent, CheckFun) \
-    PYBIND11_OBJECT(Name, Parent, CheckFun) \
-    Name() : Parent() { }
+#define PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun)                                            \
+public:                                                                                           \
+    PYBIND11_DEPRECATED("Use reinterpret_borrow<" #Name ">() or reinterpret_steal<" #Name ">()")  \
+    Name(handle h, bool is_borrowed)                                                              \
+        : Parent(is_borrowed ? Parent(h, borrowed_t{}) : Parent(h, stolen_t{})) {}                \
+    Name(handle h, borrowed_t) : Parent(h, borrowed_t{}) {}                                       \
+    Name(handle h, stolen_t) : Parent(h, stolen_t{}) {}                                           \
+    PYBIND11_DEPRECATED("Use py::isinstance<py::python_type>(obj) instead")                       \
+    bool check() const { return m_ptr != nullptr && (CheckFun(m_ptr) != 0); }                     \
+    static bool check_(handle h) { return h.ptr() != nullptr && CheckFun(h.ptr()); }              \
+    template <typename Policy_> /* NOLINTNEXTLINE(google-explicit-constructor) */                 \
+    Name(const ::pybind11::detail::accessor<Policy_> &a) : Name(object(a)) {}
+
+#define PYBIND11_OBJECT_CVT(Name, Parent, CheckFun, ConvertFun)                                   \
+    PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun)                                                \
+    /* This is deliberately not 'explicit' to allow implicit conversion from object: */           \
+    /* NOLINTNEXTLINE(google-explicit-constructor) */                                             \
+    Name(const object &o)                                                                         \
+        : Parent(check_(o) ? o.inc_ref().ptr() : ConvertFun(o.ptr()), stolen_t{}) {               \
+        if (!m_ptr)                                                                               \
+            throw error_already_set();                                                            \
+    }                                                                                             \
+    /* NOLINTNEXTLINE(google-explicit-constructor) */                                             \
+    Name(object &&o) : Parent(check_(o) ? o.release().ptr() : ConvertFun(o.ptr()), stolen_t{}) {  \
+        if (!m_ptr)                                                                               \
+            throw error_already_set();                                                            \
+    }
+
+#define PYBIND11_OBJECT_CVT_DEFAULT(Name, Parent, CheckFun, ConvertFun)                           \
+    PYBIND11_OBJECT_CVT(Name, Parent, CheckFun, ConvertFun)                                       \
+    Name() : Parent() {}
+
+#define PYBIND11_OBJECT_CHECK_FAILED(Name, o_ptr)                                                 \
+    ::pybind11::type_error("Object of type '"                                                     \
+                           + ::pybind11::detail::get_fully_qualified_tp_name(Py_TYPE(o_ptr))      \
+                           + "' is not an instance of '" #Name "'")
+
+#define PYBIND11_OBJECT(Name, Parent, CheckFun)                                                   \
+    PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun)                                                \
+    /* This is deliberately not 'explicit' to allow implicit conversion from object: */           \
+    /* NOLINTNEXTLINE(google-explicit-constructor) */                                             \
+    Name(const object &o) : Parent(o) {                                                           \
+        if (m_ptr && !check_(m_ptr))                                                              \
+            throw PYBIND11_OBJECT_CHECK_FAILED(Name, m_ptr);                                      \
+    }                                                                                             \
+    /* NOLINTNEXTLINE(google-explicit-constructor) */                                             \
+    Name(object &&o) : Parent(std::move(o)) {                                                     \
+        if (m_ptr && !check_(m_ptr))                                                              \
+            throw PYBIND11_OBJECT_CHECK_FAILED(Name, m_ptr);                                      \
+    }
+
+#define PYBIND11_OBJECT_DEFAULT(Name, Parent, CheckFun)                                           \
+    PYBIND11_OBJECT(Name, Parent, CheckFun)                                                       \
+    Name() : Parent() {}
 
 /// \addtogroup pytypes
 /// @{
@@ -986,7 +1106,7 @@ class iterator : public object {
 
     PYBIND11_OBJECT_DEFAULT(iterator, object, PyIter_Check)
 
-    iterator& operator++() {
+    iterator &operator++() {
         advance();
         return *this;
     }
@@ -1000,13 +1120,16 @@ class iterator : public object {
     // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
     reference operator*() const {
         if (m_ptr && !value.ptr()) {
-            auto& self = const_cast<iterator &>(*this);
+            auto &self = const_cast<iterator &>(*this);
             self.advance();
         }
         return value;
     }
 
-    pointer operator->() const { operator*(); return &value; }
+    pointer operator->() const {
+        operator*();
+        return &value;
+    }
 
     /** \rst
          The value which marks the end of the iteration. ``it == iterator::sentinel()``
@@ -1029,21 +1152,21 @@ class iterator : public object {
 private:
     void advance() {
         value = reinterpret_steal<object>(PyIter_Next(m_ptr));
-        if (PyErr_Occurred()) { throw error_already_set(); }
+        if (PyErr_Occurred()) {
+            throw error_already_set();
+        }
     }
 
 private:
     object value = {};
 };
 
-
-
 class type : public object {
 public:
     PYBIND11_OBJECT(type, object, PyType_Check)
 
     /// Return a type handle from a handle or an object
-    static handle handle_of(handle h) { return handle((PyObject*) Py_TYPE(h.ptr())); }
+    static handle handle_of(handle h) { return handle((PyObject *) Py_TYPE(h.ptr())); }
 
     /// Return a type object from a handle or an object
     static type of(handle h) { return type(type::handle_of(h), borrowed_t{}); }
@@ -1052,14 +1175,16 @@ class type : public object {
     /// Convert C++ type to handle if previously registered. Does not convert
     /// standard types, like int, float. etc. yet.
     /// See https://github.com/pybind/pybind11/issues/2486
-    template<typename T>
+    template <typename T>
     static handle handle_of();
 
     /// Convert C++ type to type if previously registered. Does not convert
     /// standard types, like int, float. etc. yet.
     /// See https://github.com/pybind/pybind11/issues/2486
-    template<typename T>
-    static type of() {return type(type::handle_of<T>(), borrowed_t{}); }
+    template <typename T>
+    static type of() {
+        return type(type::handle_of<T>(), borrowed_t{});
+    }
 };
 
 class iterable : public object {
@@ -1076,30 +1201,32 @@ class str : public object {
     template <typename SzType, detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
     str(const char *c, const SzType &n)
         : object(PyUnicode_FromStringAndSize(c, ssize_t_cast(n)), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate string object!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate string object!");
     }
 
-    // 'explicit' is explicitly omitted from the following constructors to allow implicit conversion to py::str from C++ string-like objects
+    // 'explicit' is explicitly omitted from the following constructors to allow implicit
+    // conversion to py::str from C++ string-like objects
     // NOLINTNEXTLINE(google-explicit-constructor)
-    str(const char *c = "")
-        : object(PyUnicode_FromString(c), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate string object!");
+    str(const char *c = "") : object(PyUnicode_FromString(c), stolen_t{}) {
+        if (!m_ptr)
+            pybind11_fail("Could not allocate string object!");
     }
 
     // NOLINTNEXTLINE(google-explicit-constructor)
-    str(const std::string &s) : str(s.data(), s.size()) { }
+    str(const std::string &s) : str(s.data(), s.size()) {}
 
 #ifdef PYBIND11_HAS_STRING_VIEW
     // enable_if is needed to avoid "ambiguous conversion" errors (see PR #3521).
     template <typename T, detail::enable_if_t<std::is_same<T, std::string_view>::value, int> = 0>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    str(T s) : str(s.data(), s.size()) { }
+    str(T s) : str(s.data(), s.size()) {}
 
-# ifdef PYBIND11_HAS_U8STRING
+#    ifdef PYBIND11_HAS_U8STRING
     // reinterpret_cast here is safe (C++20 guarantees char8_t has the same size/alignment as char)
     // NOLINTNEXTLINE(google-explicit-constructor)
-    str(std::u8string_view s) : str(reinterpret_cast<const char*>(s.data()), s.size()) { }
-# endif
+    str(std::u8string_view s) : str(reinterpret_cast<const char *>(s.data()), s.size()) {}
+#    endif
 
 #endif
 
@@ -1109,7 +1236,10 @@ class str : public object {
         Return a string representation of the object. This is analogous to
         the ``str()`` function in Python.
     \endrst */
-    explicit str(handle h) : object(raw_str(h.ptr()), stolen_t{}) { if (!m_ptr) throw error_already_set(); }
+    explicit str(handle h) : object(raw_str(h.ptr()), stolen_t{}) {
+        if (!m_ptr)
+            throw error_already_set();
+    }
 
     // NOLINTNEXTLINE(google-explicit-constructor)
     operator std::string() const {
@@ -1136,9 +1266,11 @@ class str : public object {
     static PyObject *raw_str(PyObject *op) {
         PyObject *str_value = PyObject_Str(op);
 #if PY_MAJOR_VERSION < 3
-        if (!str_value) throw error_already_set();
+        if (!str_value)
+            throw error_already_set();
         PyObject *unicode = PyUnicode_FromEncodedObject(str_value, "utf-8", nullptr);
-        Py_XDECREF(str_value); str_value = unicode;
+        Py_XDECREF(str_value);
+        str_value = unicode;
 #endif
         return str_value;
     }
@@ -1160,20 +1292,21 @@ class bytes : public object {
 
     // Allow implicit conversion:
     // NOLINTNEXTLINE(google-explicit-constructor)
-    bytes(const char *c = "")
-        : object(PYBIND11_BYTES_FROM_STRING(c), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate bytes object!");
+    bytes(const char *c = "") : object(PYBIND11_BYTES_FROM_STRING(c), stolen_t{}) {
+        if (!m_ptr)
+            pybind11_fail("Could not allocate bytes object!");
     }
 
     template <typename SzType, detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
     bytes(const char *c, const SzType &n)
         : object(PYBIND11_BYTES_FROM_STRING_AND_SIZE(c, ssize_t_cast(n)), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate bytes object!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate bytes object!");
     }
 
     // Allow implicit conversion:
     // NOLINTNEXTLINE(google-explicit-constructor)
-    bytes(const std::string &s) : bytes(s.data(), s.size()) { }
+    bytes(const std::string &s) : bytes(s.data(), s.size()) {}
 
     explicit bytes(const pybind11::str &s);
 
@@ -1190,7 +1323,7 @@ class bytes : public object {
     // enable_if is needed to avoid "ambiguous conversion" errors (see PR #3521).
     template <typename T, detail::enable_if_t<std::is_same<T, std::string_view>::value, int> = 0>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    bytes(T s) : bytes(s.data(), s.size()) { }
+    bytes(T s) : bytes(s.data(), s.size()) {}
 
     // Obtain a string view that views the current `bytes` buffer value.  Note that this is only
     // valid so long as the `bytes` instance remains alive and so generally should not outlive the
@@ -1204,7 +1337,6 @@ class bytes : public object {
         return {buffer, static_cast<size_t>(length)};
     }
 #endif
-
 };
 // Note: breathe >= 4.17.0 will fail to build docs if the below two constructors
 // are included in the doxygen group; close here and reopen after as a workaround
@@ -1227,7 +1359,7 @@ inline bytes::bytes(const pybind11::str &s) {
     m_ptr = obj.release().ptr();
 }
 
-inline str::str(const bytes& b) {
+inline str::str(const bytes &b) {
     char *buffer = nullptr;
     ssize_t length = 0;
     if (PYBIND11_BYTES_AS_STRING_AND_SIZE(b.ptr(), &buffer, &length))
@@ -1247,13 +1379,13 @@ class bytearray : public object {
     template <typename SzType, detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
     bytearray(const char *c, const SzType &n)
         : object(PyByteArray_FromStringAndSize(c, ssize_t_cast(n)), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate bytearray object!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate bytearray object!");
     }
 
-    bytearray()
-        : bytearray("", 0) {}
+    bytearray() : bytearray("", 0) {}
 
-    explicit bytearray(const std::string &s) : bytearray(s.data(), s.size()) { }
+    explicit bytearray(const std::string &s) : bytearray(s.data(), s.size()) {}
 
     size_t size() const { return static_cast<size_t>(PyByteArray_Size(m_ptr)); }
 
@@ -1272,22 +1404,22 @@ class bytearray : public object {
 class none : public object {
 public:
     PYBIND11_OBJECT(none, object, detail::PyNone_Check)
-    none() : object(Py_None, borrowed_t{}) { }
+    none() : object(Py_None, borrowed_t{}) {}
 };
 
 class ellipsis : public object {
 public:
     PYBIND11_OBJECT(ellipsis, object, detail::PyEllipsis_Check)
-    ellipsis() : object(Py_Ellipsis, borrowed_t{}) { }
+    ellipsis() : object(Py_Ellipsis, borrowed_t{}) {}
 };
 
 class bool_ : public object {
 public:
     PYBIND11_OBJECT_CVT(bool_, object, PyBool_Check, raw_bool)
-    bool_() : object(Py_False, borrowed_t{}) { }
+    bool_() : object(Py_False, borrowed_t{}) {}
     // Allow implicit conversion from and to `bool`:
     // NOLINTNEXTLINE(google-explicit-constructor)
-    bool_(bool value) : object(value ? Py_True : Py_False, borrowed_t{}) { }
+    bool_(bool value) : object(value ? Py_True : Py_False, borrowed_t{}) {}
     // NOLINTNEXTLINE(google-explicit-constructor)
     operator bool() const { return (m_ptr != nullptr) && PyLong_AsLong(m_ptr) != 0; }
 
@@ -1295,7 +1427,8 @@ class bool_ : public object {
     /// Return the truth value of an object -- always returns a new reference
     static PyObject *raw_bool(PyObject *op) {
         const auto value = PyObject_IsTrue(op);
-        if (value == -1) return nullptr;
+        if (value == -1)
+            return nullptr;
         return handle(value != 0 ? Py_True : Py_False).inc_ref().ptr();
     }
 };
@@ -1323,10 +1456,9 @@ PYBIND11_NAMESPACE_END(detail)
 class int_ : public object {
 public:
     PYBIND11_OBJECT_CVT(int_, object, PYBIND11_LONG_CHECK, PyNumber_Long)
-    int_() : object(PyLong_FromLong(0), stolen_t{}) { }
+    int_() : object(PyLong_FromLong(0), stolen_t{}) {}
     // Allow implicit conversion from C++ integral types:
-    template <typename T,
-              detail::enable_if_t<std::is_integral<T>::value, int> = 0>
+    template <typename T, detail::enable_if_t<std::is_integral<T>::value, int> = 0>
     // NOLINTNEXTLINE(google-explicit-constructor)
     int_(T value) {
         if (PYBIND11_SILENCE_MSVC_C4127(sizeof(T) <= sizeof(long))) {
@@ -1340,18 +1472,16 @@ class int_ : public object {
             else
                 m_ptr = PyLong_FromUnsignedLongLong((unsigned long long) value);
         }
-        if (!m_ptr) pybind11_fail("Could not allocate int object!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate int object!");
     }
 
-    template <typename T,
-              detail::enable_if_t<std::is_integral<T>::value, int> = 0>
+    template <typename T, detail::enable_if_t<std::is_integral<T>::value, int> = 0>
     // NOLINTNEXTLINE(google-explicit-constructor)
     operator T() const {
-        return std::is_unsigned<T>::value
-            ? detail::as_unsigned<T>(m_ptr)
-            : sizeof(T) <= sizeof(long)
-              ? (T) PyLong_AsLong(m_ptr)
-              : (T) PYBIND11_LONG_AS_LONGLONG(m_ptr);
+        return std::is_unsigned<T>::value  ? detail::as_unsigned<T>(m_ptr)
+               : sizeof(T) <= sizeof(long) ? (T) PyLong_AsLong(m_ptr)
+                                           : (T) PYBIND11_LONG_AS_LONGLONG(m_ptr);
     }
 };
 
@@ -1361,11 +1491,13 @@ class float_ : public object {
     // Allow implicit conversion from float/double:
     // NOLINTNEXTLINE(google-explicit-constructor)
     float_(float value) : object(PyFloat_FromDouble((double) value), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate float object!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate float object!");
     }
     // NOLINTNEXTLINE(google-explicit-constructor)
     float_(double value = .0) : object(PyFloat_FromDouble((double) value), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate float object!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate float object!");
     }
     // NOLINTNEXTLINE(google-explicit-constructor)
     operator float() const { return (float) PyFloat_AsDouble(m_ptr); }
@@ -1378,13 +1510,12 @@ class weakref : public object {
     PYBIND11_OBJECT_CVT_DEFAULT(weakref, object, PyWeakref_Check, raw_weakref)
     explicit weakref(handle obj, handle callback = {})
         : object(PyWeakref_NewRef(obj.ptr(), callback.ptr()), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate weak reference!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate weak reference!");
     }
 
 private:
-    static PyObject *raw_weakref(PyObject *o) {
-        return PyWeakref_NewRef(o, nullptr);
-    }
+    static PyObject *raw_weakref(PyObject *o) { return PyWeakref_NewRef(o, nullptr); }
 };
 
 class slice : public object {
@@ -1404,19 +1535,21 @@ class slice : public object {
         : slice(int_(start_), int_(stop_), int_(step_)) {}
 #endif
 
-    bool compute(size_t length, size_t *start, size_t *stop, size_t *step,
-                 size_t *slicelength) const {
+    bool
+    compute(size_t length, size_t *start, size_t *stop, size_t *step, size_t *slicelength) const {
         return PySlice_GetIndicesEx((PYBIND11_SLICE_OBJECT *) m_ptr,
-                                    (ssize_t) length, (ssize_t *) start,
-                                    (ssize_t *) stop, (ssize_t *) step,
-                                    (ssize_t *) slicelength) == 0;
+                                    (ssize_t) length,
+                                    (ssize_t *) start,
+                                    (ssize_t *) stop,
+                                    (ssize_t *) step,
+                                    (ssize_t *) slicelength)
+               == 0;
     }
-    bool compute(ssize_t length, ssize_t *start, ssize_t *stop, ssize_t *step,
-      ssize_t *slicelength) const {
-      return PySlice_GetIndicesEx((PYBIND11_SLICE_OBJECT *) m_ptr,
-          length, start,
-          stop, step,
-          slicelength) == 0;
+    bool compute(
+        ssize_t length, ssize_t *start, ssize_t *stop, ssize_t *step, ssize_t *slicelength) const {
+        return PySlice_GetIndicesEx(
+                   (PYBIND11_SLICE_OBJECT *) m_ptr, length, start, stop, step, slicelength)
+               == 0;
     }
 
 private:
@@ -1430,9 +1563,12 @@ class capsule : public object {
 public:
     PYBIND11_OBJECT_DEFAULT(capsule, object, PyCapsule_CheckExact)
     PYBIND11_DEPRECATED("Use reinterpret_borrow<capsule>() or reinterpret_steal<capsule>()")
-    capsule(PyObject *ptr, bool is_borrowed) : object(is_borrowed ? object(ptr, borrowed_t{}) : object(ptr, stolen_t{})) { }
+    capsule(PyObject *ptr, bool is_borrowed)
+        : object(is_borrowed ? object(ptr, borrowed_t{}) : object(ptr, stolen_t{})) {}
 
-    explicit capsule(const void *value, const char *name = nullptr, void (*destructor)(PyObject *) = nullptr)
+    explicit capsule(const void *value,
+                     const char *name = nullptr,
+                     void (*destructor)(PyObject *) = nullptr)
         : object(PyCapsule_New(const_cast<void *>(value), name, destructor), stolen_t{}) {
         if (!m_ptr)
             pybind11_fail("Could not allocate capsule object!");
@@ -1440,7 +1576,7 @@ class capsule : public object {
 
     PYBIND11_DEPRECATED("Please pass a destructor that takes a void pointer as input")
     capsule(const void *value, void (*destruct)(PyObject *))
-        : object(PyCapsule_New(const_cast<void*>(value), nullptr, destruct), stolen_t{}) {
+        : object(PyCapsule_New(const_cast<void *>(value), nullptr, destruct), stolen_t{}) {
         if (!m_ptr)
             pybind11_fail("Could not allocate capsule object!");
     }
@@ -1469,15 +1605,16 @@ class capsule : public object {
             pybind11_fail("Could not allocate capsule object!");
     }
 
+    template <typename T>
     // NOLINTNEXTLINE(google-explicit-constructor)
-    template <typename T> operator T *() const {
+    operator T *() const {
         return get_pointer<T>();
     }
 
     /// Get the pointer the capsule holds.
-    template<typename T = void>
-    T* get_pointer() const {
-        auto name = this->name();
+    template <typename T = void>
+    T *get_pointer() const {
+        const auto *name = this->name();
         T *result = static_cast<T *>(PyCapsule_GetPointer(m_ptr, name));
         if (!result) {
             PyErr_Clear();
@@ -1504,7 +1641,8 @@ class tuple : public object {
               detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
     // Some compilers generate link errors when using `const SzType &` here:
     explicit tuple(SzType size = 0) : object(PyTuple_New(ssize_t_cast(size)), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate tuple object!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate tuple object!");
     }
     size_t size() const { return (size_t) PyTuple_Size(m_ptr); }
     bool empty() const { return size() == 0; }
@@ -1518,29 +1656,31 @@ class tuple : public object {
 // fails to compile enable_if_t<all_of<is_keyword_or_ds<Args>...>::value> part below
 // (tested with ICC 2021.1 Beta 20200827).
 template <typename... Args>
-constexpr bool args_are_all_keyword_or_ds()
-{
-  return detail::all_of<detail::is_keyword_or_ds<Args>...>::value;
+constexpr bool args_are_all_keyword_or_ds() {
+    return detail::all_of<detail::is_keyword_or_ds<Args>...>::value;
 }
 
 class dict : public object {
 public:
     PYBIND11_OBJECT_CVT(dict, object, PyDict_Check, raw_dict)
     dict() : object(PyDict_New(), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate dict object!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate dict object!");
     }
     template <typename... Args,
               typename = detail::enable_if_t<args_are_all_keyword_or_ds<Args...>()>,
-              // MSVC workaround: it can't compile an out-of-line definition, so defer the collector
+              // MSVC workaround: it can't compile an out-of-line definition, so defer the
+              // collector
               typename collector = detail::deferred_t<detail::unpacking_collector<>, Args...>>
-    explicit dict(Args &&...args) : dict(collector(std::forward<Args>(args)...).kwargs()) { }
+    explicit dict(Args &&...args) : dict(collector(std::forward<Args>(args)...).kwargs()) {}
 
     size_t size() const { return (size_t) PyDict_Size(m_ptr); }
     bool empty() const { return size() == 0; }
     detail::dict_iterator begin() const { return {*this, 0}; }
     detail::dict_iterator end() const { return {}; }
     void clear() /* py-non-const */ { PyDict_Clear(ptr()); }
-    template <typename T> bool contains(T &&key) const {
+    template <typename T>
+    bool contains(T &&key) const {
         return PyDict_Contains(m_ptr, detail::object_or_cast(std::forward<T>(key)).ptr()) == 1;
     }
 
@@ -1576,7 +1716,8 @@ class list : public object {
               detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
     // Some compilers generate link errors when using `const SzType &` here:
     explicit list(SzType size = 0) : object(PyList_New(ssize_t_cast(size)), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate list object!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate list object!");
     }
     size_t size() const { return (size_t) PyList_Size(m_ptr); }
     bool empty() const { return size() == 0; }
@@ -1584,7 +1725,8 @@ class list : public object {
     detail::item_accessor operator[](handle h) const { return object::operator[](h); }
     detail::list_iterator begin() const { return {*this, 0}; }
     detail::list_iterator end() const { return {*this, PyList_GET_SIZE(m_ptr)}; }
-    template <typename T> void append(T &&val) /* py-non-const */ {
+    template <typename T>
+    void append(T &&val) /* py-non-const */ {
         PyList_Append(m_ptr, detail::object_or_cast(std::forward<T>(val)).ptr());
     }
     template <typename IdxType,
@@ -1596,22 +1738,29 @@ class list : public object {
     }
 };
 
-class args : public tuple { PYBIND11_OBJECT_DEFAULT(args, tuple, PyTuple_Check) };
-class kwargs : public dict { PYBIND11_OBJECT_DEFAULT(kwargs, dict, PyDict_Check)  };
+class args : public tuple {
+    PYBIND11_OBJECT_DEFAULT(args, tuple, PyTuple_Check)
+};
+class kwargs : public dict {
+    PYBIND11_OBJECT_DEFAULT(kwargs, dict, PyDict_Check)
+};
 
 class set : public object {
 public:
     PYBIND11_OBJECT_CVT(set, object, PySet_Check, PySet_New)
     set() : object(PySet_New(nullptr), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate set object!");
+        if (!m_ptr)
+            pybind11_fail("Could not allocate set object!");
     }
     size_t size() const { return (size_t) PySet_Size(m_ptr); }
     bool empty() const { return size() == 0; }
-    template <typename T> bool add(T &&val) /* py-non-const */ {
+    template <typename T>
+    bool add(T &&val) /* py-non-const */ {
         return PySet_Add(m_ptr, detail::object_or_cast(std::forward<T>(val)).ptr()) == 0;
     }
     void clear() /* py-non-const */ { PySet_Clear(m_ptr); }
-    template <typename T> bool contains(T &&val) const {
+    template <typename T>
+    bool contains(T &&val) const {
         return PySet_Contains(m_ptr, detail::object_or_cast(std::forward<T>(val)).ptr()) == 1;
     }
 };
@@ -1639,7 +1788,8 @@ class buffer : public object {
 
     buffer_info request(bool writable = false) const {
         int flags = PyBUF_STRIDES | PyBUF_FORMAT;
-        if (writable) flags |= PyBUF_WRITABLE;
+        if (writable)
+            flags |= PyBUF_WRITABLE;
         auto *view = new Py_buffer();
         if (PyObject_GetBuffer(m_ptr, view, flags) != 0) {
             delete view;
@@ -1662,13 +1812,12 @@ class memoryview : public object {
         For creating a ``memoryview`` from objects that support buffer protocol,
         use ``memoryview(const object& obj)`` instead of this constructor.
      \endrst */
-    explicit memoryview(const buffer_info& info) {
+    explicit memoryview(const buffer_info &info) {
         if (!info.view())
             pybind11_fail("Prohibited to create memoryview without Py_buffer");
         // Note: PyMemoryView_FromBuffer never increments obj reference.
-        m_ptr = (info.view()->obj) ?
-            PyMemoryView_FromObject(info.view()->obj) :
-            PyMemoryView_FromBuffer(info.view());
+        m_ptr = (info.view()->obj) ? PyMemoryView_FromObject(info.view()->obj)
+                                   : PyMemoryView_FromBuffer(info.view());
         if (!m_ptr)
             pybind11_fail("Unable to create memoryview from buffer descriptor");
     }
@@ -1696,34 +1845,40 @@ class memoryview : public object {
         :param readonly: Flag to indicate if the underlying storage may be
             written to.
      \endrst */
-    static memoryview from_buffer(
-        void *ptr, ssize_t itemsize, const char *format,
-        detail::any_container<ssize_t> shape,
-        detail::any_container<ssize_t> strides, bool readonly = false);
-
-    static memoryview from_buffer(
-        const void *ptr, ssize_t itemsize, const char *format,
-        detail::any_container<ssize_t> shape,
-        detail::any_container<ssize_t> strides) {
+    static memoryview from_buffer(void *ptr,
+                                  ssize_t itemsize,
+                                  const char *format,
+                                  detail::any_container<ssize_t> shape,
+                                  detail::any_container<ssize_t> strides,
+                                  bool readonly = false);
+
+    static memoryview from_buffer(const void *ptr,
+                                  ssize_t itemsize,
+                                  const char *format,
+                                  detail::any_container<ssize_t> shape,
+                                  detail::any_container<ssize_t> strides) {
         return memoryview::from_buffer(
             const_cast<void *>(ptr), itemsize, format, std::move(shape), std::move(strides), true);
     }
 
-    template<typename T>
-    static memoryview from_buffer(
-        T *ptr, detail::any_container<ssize_t> shape,
-        detail::any_container<ssize_t> strides, bool readonly = false) {
-        return memoryview::from_buffer(
-            reinterpret_cast<void*>(ptr), sizeof(T),
-            format_descriptor<T>::value, shape, strides, readonly);
+    template <typename T>
+    static memoryview from_buffer(T *ptr,
+                                  detail::any_container<ssize_t> shape,
+                                  detail::any_container<ssize_t> strides,
+                                  bool readonly = false) {
+        return memoryview::from_buffer(reinterpret_cast<void *>(ptr),
+                                       sizeof(T),
+                                       format_descriptor<T>::value,
+                                       shape,
+                                       strides,
+                                       readonly);
     }
 
-    template<typename T>
-    static memoryview from_buffer(
-        const T *ptr, detail::any_container<ssize_t> shape,
-        detail::any_container<ssize_t> strides) {
-        return memoryview::from_buffer(
-            const_cast<T*>(ptr), shape, strides, true);
+    template <typename T>
+    static memoryview from_buffer(const T *ptr,
+                                  detail::any_container<ssize_t> shape,
+                                  detail::any_container<ssize_t> strides) {
+        return memoryview::from_buffer(const_cast<T *>(ptr), shape, strides, true);
     }
 
 #if PY_MAJOR_VERSION >= 3
@@ -1738,35 +1893,35 @@ class memoryview : public object {
 
         See also: Python C API documentation for `PyMemoryView_FromBuffer`_.
 
-        .. _PyMemoryView_FromMemory: https://docs.python.org/c-api/memoryview.html#c.PyMemoryView_FromMemory
-     \endrst */
+        .. _PyMemoryView_FromMemory: https://docs.python.org/c-api/memoryview.html#c.PyMemoryView_FromMemory \endrst */
     static memoryview from_memory(void *mem, ssize_t size, bool readonly = false) {
-        PyObject* ptr = PyMemoryView_FromMemory(
-            reinterpret_cast<char*>(mem), size,
-            (readonly) ? PyBUF_READ : PyBUF_WRITE);
+        PyObject *ptr = PyMemoryView_FromMemory(
+            reinterpret_cast<char *>(mem), size, (readonly) ? PyBUF_READ : PyBUF_WRITE);
         if (!ptr)
             pybind11_fail("Could not allocate memoryview object!");
         return memoryview(object(ptr, stolen_t{}));
     }
 
     static memoryview from_memory(const void *mem, ssize_t size) {
-        return memoryview::from_memory(const_cast<void*>(mem), size, true);
+        return memoryview::from_memory(const_cast<void *>(mem), size, true);
     }
 
-#ifdef PYBIND11_HAS_STRING_VIEW
+#    ifdef PYBIND11_HAS_STRING_VIEW
     static memoryview from_memory(std::string_view mem) {
-        return from_memory(const_cast<char*>(mem.data()), static_cast<ssize_t>(mem.size()), true);
+        return from_memory(const_cast<char *>(mem.data()), static_cast<ssize_t>(mem.size()), true);
     }
-#endif
+#    endif
 
 #endif
 };
 
 /// @cond DUPLICATE
-inline memoryview memoryview::from_buffer(
-    void *ptr, ssize_t itemsize, const char* format,
-    detail::any_container<ssize_t> shape,
-    detail::any_container<ssize_t> strides, bool readonly) {
+inline memoryview memoryview::from_buffer(void *ptr,
+                                          ssize_t itemsize,
+                                          const char *format,
+                                          detail::any_container<ssize_t> shape,
+                                          detail::any_container<ssize_t> strides,
+                                          bool readonly) {
     size_t ndim = shape->size();
     if (ndim != strides->size())
         pybind11_fail("memoryview: shape length doesn't match strides length");
@@ -1779,13 +1934,13 @@ inline memoryview memoryview::from_buffer(
     view.len = size * itemsize;
     view.readonly = static_cast<int>(readonly);
     view.itemsize = itemsize;
-    view.format = const_cast<char*>(format);
+    view.format = const_cast<char *>(format);
     view.ndim = static_cast<int>(ndim);
     view.shape = shape->data();
     view.strides = strides->data();
     view.suboffsets = nullptr;
     view.internal = nullptr;
-    PyObject* obj = PyMemoryView_FromBuffer(&view);
+    PyObject *obj = PyMemoryView_FromBuffer(&view);
     if (!obj)
         throw error_already_set();
     return memoryview(object(obj, stolen_t{}));
@@ -1823,52 +1978,76 @@ inline size_t len_hint(handle h) {
 
 inline str repr(handle h) {
     PyObject *str_value = PyObject_Repr(h.ptr());
-    if (!str_value) throw error_already_set();
+    if (!str_value)
+        throw error_already_set();
 #if PY_MAJOR_VERSION < 3
     PyObject *unicode = PyUnicode_FromEncodedObject(str_value, "utf-8", nullptr);
-    Py_XDECREF(str_value); str_value = unicode;
-    if (!str_value) throw error_already_set();
+    Py_XDECREF(str_value);
+    str_value = unicode;
+    if (!str_value)
+        throw error_already_set();
 #endif
     return reinterpret_steal<str>(str_value);
 }
 
 inline iterator iter(handle obj) {
     PyObject *result = PyObject_GetIter(obj.ptr());
-    if (!result) { throw error_already_set(); }
+    if (!result) {
+        throw error_already_set();
+    }
     return reinterpret_steal<iterator>(result);
 }
 /// @} python_builtins
 
 PYBIND11_NAMESPACE_BEGIN(detail)
-template <typename D> iterator object_api<D>::begin() const { return iter(derived()); }
-template <typename D> iterator object_api<D>::end() const { return iterator::sentinel(); }
-template <typename D> item_accessor object_api<D>::operator[](handle key) const {
+template <typename D>
+iterator object_api<D>::begin() const {
+    return iter(derived());
+}
+template <typename D>
+iterator object_api<D>::end() const {
+    return iterator::sentinel();
+}
+template <typename D>
+item_accessor object_api<D>::operator[](handle key) const {
     return {derived(), reinterpret_borrow<object>(key)};
 }
-template <typename D> item_accessor object_api<D>::operator[](const char *key) const {
+template <typename D>
+item_accessor object_api<D>::operator[](const char *key) const {
     return {derived(), pybind11::str(key)};
 }
-template <typename D> obj_attr_accessor object_api<D>::attr(handle key) const {
+template <typename D>
+obj_attr_accessor object_api<D>::attr(handle key) const {
     return {derived(), reinterpret_borrow<object>(key)};
 }
-template <typename D> str_attr_accessor object_api<D>::attr(const char *key) const {
+template <typename D>
+str_attr_accessor object_api<D>::attr(const char *key) const {
     return {derived(), key};
 }
-template <typename D> args_proxy object_api<D>::operator*() const {
+template <typename D>
+args_proxy object_api<D>::operator*() const {
     return args_proxy(derived().ptr());
 }
-template <typename D> template <typename T> bool object_api<D>::contains(T &&item) const {
+template <typename D>
+template <typename T>
+bool object_api<D>::contains(T &&item) const {
     return attr("__contains__")(std::forward<T>(item)).template cast<bool>();
 }
 
 template <typename D>
-pybind11::str object_api<D>::str() const { return pybind11::str(derived()); }
+pybind11::str object_api<D>::str() const {
+    return pybind11::str(derived());
+}
 
 template <typename D>
-str_attr_accessor object_api<D>::doc() const { return attr("__doc__"); }
+str_attr_accessor object_api<D>::doc() const {
+    return attr("__doc__");
+}
 
 template <typename D>
-handle object_api<D>::get_type() const { return type::handle_of(derived()); }
+handle object_api<D>::get_type() const {
+    return type::handle_of(derived());
+}
 
 template <typename D>
 bool object_api<D>::rich_compare(object_api const &other, int value) const {
@@ -1878,43 +2057,43 @@ bool object_api<D>::rich_compare(object_api const &other, int value) const {
     return rv == 1;
 }
 
-#define PYBIND11_MATH_OPERATOR_UNARY(op, fn)                                   \
-    template <typename D> object object_api<D>::op() const {                   \
-        object result = reinterpret_steal<object>(fn(derived().ptr()));        \
-        if (!result.ptr())                                                     \
-            throw error_already_set();                                         \
-        return result;                                                         \
-    }
-
-#define PYBIND11_MATH_OPERATOR_BINARY(op, fn)                                  \
-    template <typename D>                                                      \
-    object object_api<D>::op(object_api const &other) const {                  \
-        object result = reinterpret_steal<object>(                             \
-            fn(derived().ptr(), other.derived().ptr()));                       \
-        if (!result.ptr())                                                     \
-            throw error_already_set();                                         \
-        return result;                                                         \
-    }
-
-PYBIND11_MATH_OPERATOR_UNARY (operator~,   PyNumber_Invert)
-PYBIND11_MATH_OPERATOR_UNARY (operator-,   PyNumber_Negative)
-PYBIND11_MATH_OPERATOR_BINARY(operator+,   PyNumber_Add)
-PYBIND11_MATH_OPERATOR_BINARY(operator+=,  PyNumber_InPlaceAdd)
-PYBIND11_MATH_OPERATOR_BINARY(operator-,   PyNumber_Subtract)
-PYBIND11_MATH_OPERATOR_BINARY(operator-=,  PyNumber_InPlaceSubtract)
-PYBIND11_MATH_OPERATOR_BINARY(operator*,   PyNumber_Multiply)
-PYBIND11_MATH_OPERATOR_BINARY(operator*=,  PyNumber_InPlaceMultiply)
-PYBIND11_MATH_OPERATOR_BINARY(operator/,   PyNumber_TrueDivide)
-PYBIND11_MATH_OPERATOR_BINARY(operator/=,  PyNumber_InPlaceTrueDivide)
-PYBIND11_MATH_OPERATOR_BINARY(operator|,   PyNumber_Or)
-PYBIND11_MATH_OPERATOR_BINARY(operator|=,  PyNumber_InPlaceOr)
-PYBIND11_MATH_OPERATOR_BINARY(operator&,   PyNumber_And)
-PYBIND11_MATH_OPERATOR_BINARY(operator&=,  PyNumber_InPlaceAnd)
-PYBIND11_MATH_OPERATOR_BINARY(operator^,   PyNumber_Xor)
-PYBIND11_MATH_OPERATOR_BINARY(operator^=,  PyNumber_InPlaceXor)
-PYBIND11_MATH_OPERATOR_BINARY(operator<<,  PyNumber_Lshift)
+#define PYBIND11_MATH_OPERATOR_UNARY(op, fn)                                                      \
+    template <typename D>                                                                         \
+    object object_api<D>::op() const {                                                            \
+        object result = reinterpret_steal<object>(fn(derived().ptr()));                           \
+        if (!result.ptr())                                                                        \
+            throw error_already_set();                                                            \
+        return result;                                                                            \
+    }
+
+#define PYBIND11_MATH_OPERATOR_BINARY(op, fn)                                                     \
+    template <typename D>                                                                         \
+    object object_api<D>::op(object_api const &other) const {                                     \
+        object result = reinterpret_steal<object>(fn(derived().ptr(), other.derived().ptr()));    \
+        if (!result.ptr())                                                                        \
+            throw error_already_set();                                                            \
+        return result;                                                                            \
+    }
+
+PYBIND11_MATH_OPERATOR_UNARY(operator~, PyNumber_Invert)
+PYBIND11_MATH_OPERATOR_UNARY(operator-, PyNumber_Negative)
+PYBIND11_MATH_OPERATOR_BINARY(operator+, PyNumber_Add)
+PYBIND11_MATH_OPERATOR_BINARY(operator+=, PyNumber_InPlaceAdd)
+PYBIND11_MATH_OPERATOR_BINARY(operator-, PyNumber_Subtract)
+PYBIND11_MATH_OPERATOR_BINARY(operator-=, PyNumber_InPlaceSubtract)
+PYBIND11_MATH_OPERATOR_BINARY(operator*, PyNumber_Multiply)
+PYBIND11_MATH_OPERATOR_BINARY(operator*=, PyNumber_InPlaceMultiply)
+PYBIND11_MATH_OPERATOR_BINARY(operator/, PyNumber_TrueDivide)
+PYBIND11_MATH_OPERATOR_BINARY(operator/=, PyNumber_InPlaceTrueDivide)
+PYBIND11_MATH_OPERATOR_BINARY(operator|, PyNumber_Or)
+PYBIND11_MATH_OPERATOR_BINARY(operator|=, PyNumber_InPlaceOr)
+PYBIND11_MATH_OPERATOR_BINARY(operator&, PyNumber_And)
+PYBIND11_MATH_OPERATOR_BINARY(operator&=, PyNumber_InPlaceAnd)
+PYBIND11_MATH_OPERATOR_BINARY(operator^, PyNumber_Xor)
+PYBIND11_MATH_OPERATOR_BINARY(operator^=, PyNumber_InPlaceXor)
+PYBIND11_MATH_OPERATOR_BINARY(operator<<, PyNumber_Lshift)
 PYBIND11_MATH_OPERATOR_BINARY(operator<<=, PyNumber_InPlaceLshift)
-PYBIND11_MATH_OPERATOR_BINARY(operator>>,  PyNumber_Rshift)
+PYBIND11_MATH_OPERATOR_BINARY(operator>>, PyNumber_Rshift)
 PYBIND11_MATH_OPERATOR_BINARY(operator>>=, PyNumber_InPlaceRshift)
 
 #undef PYBIND11_MATH_OPERATOR_UNARY
diff --git a/include/pybind11/stl.h b/include/pybind11/stl.h
index 4303494827..c5043e62f8 100644
--- a/include/pybind11/stl.h
+++ b/include/pybind11/stl.h
@@ -9,26 +9,27 @@
 
 #pragma once
 
-#include "detail/common.h"
 #include "pybind11.h"
-#include <set>
-#include <unordered_set>
-#include <map>
-#include <unordered_map>
+#include "detail/common.h"
+
+#include <deque>
 #include <iostream>
 #include <list>
-#include <deque>
+#include <map>
+#include <set>
+#include <unordered_map>
+#include <unordered_set>
 #include <valarray>
 
 // See `detail/common.h` for implementation of these guards.
 #if defined(PYBIND11_HAS_OPTIONAL)
-#  include <optional>
+#    include <optional>
 #elif defined(PYBIND11_HAS_EXP_OPTIONAL)
-#  include <experimental/optional>
+#    include <experimental/optional>
 #endif
 
 #if defined(PYBIND11_HAS_VARIANT)
-#  include <variant>
+#    include <variant>
 #endif
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
@@ -37,8 +38,9 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 /// Extracts an const lvalue reference or rvalue reference for U based on the type of T (e.g. for
 /// forwarding a container element).  Typically used indirect via forwarded_type(), below.
 template <typename T, typename U>
-using forwarded_type = conditional_t<
-    std::is_lvalue_reference<T>::value, remove_reference_t<U> &, remove_reference_t<U> &&>;
+using forwarded_type = conditional_t<std::is_lvalue_reference<T>::value,
+                                     remove_reference_t<U> &,
+                                     remove_reference_t<U> &&>;
 
 /// Forwards a value U as rvalue or lvalue according to whether T is rvalue or lvalue; typically
 /// used for forwarding a container's elements.
@@ -47,7 +49,8 @@ forwarded_type<T, U> forward_like(U &&u) {
     return std::forward<detail::forwarded_type<T, U>>(std::forward<U>(u));
 }
 
-template <typename Type, typename Key> struct set_caster {
+template <typename Type, typename Key>
+struct set_caster {
     using type = Type;
     using key_conv = make_caster<Key>;
 
@@ -71,7 +74,8 @@ template <typename Type, typename Key> struct set_caster {
             policy = return_value_policy_override<Key>::policy(policy);
         pybind11::set s;
         for (auto &&value : src) {
-            auto value_ = reinterpret_steal<object>(key_conv::cast(forward_like<T>(value), policy, parent));
+            auto value_ = reinterpret_steal<object>(
+                key_conv::cast(forward_like<T>(value), policy, parent));
             if (!value_ || !s.add(value_))
                 return handle();
         }
@@ -81,8 +85,9 @@ template <typename Type, typename Key> struct set_caster {
     PYBIND11_TYPE_CASTER(type, const_name("Set[") + key_conv::name + const_name("]"));
 };
 
-template <typename Type, typename Key, typename Value> struct map_caster {
-    using key_conv   = make_caster<Key>;
+template <typename Type, typename Key, typename Value>
+struct map_caster {
+    using key_conv = make_caster<Key>;
     using value_conv = make_caster<Value>;
 
     bool load(handle src, bool convert) {
@@ -93,8 +98,7 @@ template <typename Type, typename Key, typename Value> struct map_caster {
         for (auto it : d) {
             key_conv kconv;
             value_conv vconv;
-            if (!kconv.load(it.first.ptr(), convert) ||
-                !vconv.load(it.second.ptr(), convert))
+            if (!kconv.load(it.first.ptr(), convert) || !vconv.load(it.second.ptr(), convert))
                 return false;
             value.emplace(cast_op<Key &&>(std::move(kconv)), cast_op<Value &&>(std::move(vconv)));
         }
@@ -111,8 +115,10 @@ template <typename Type, typename Key, typename Value> struct map_caster {
             policy_value = return_value_policy_override<Value>::policy(policy_value);
         }
         for (auto &&kv : src) {
-            auto key = reinterpret_steal<object>(key_conv::cast(forward_like<T>(kv.first), policy_key, parent));
-            auto value = reinterpret_steal<object>(value_conv::cast(forward_like<T>(kv.second), policy_value, parent));
+            auto key = reinterpret_steal<object>(
+                key_conv::cast(forward_like<T>(kv.first), policy_key, parent));
+            auto value = reinterpret_steal<object>(
+                value_conv::cast(forward_like<T>(kv.second), policy_value, parent));
             if (!key || !value)
                 return handle();
             d[key] = value;
@@ -120,10 +126,13 @@ template <typename Type, typename Key, typename Value> struct map_caster {
         return d.release();
     }
 
-    PYBIND11_TYPE_CASTER(Type, const_name("Dict[") + key_conv::name + const_name(", ") + value_conv::name + const_name("]"));
+    PYBIND11_TYPE_CASTER(Type,
+                         const_name("Dict[") + key_conv::name + const_name(", ") + value_conv::name
+                             + const_name("]"));
 };
 
-template <typename Type, typename Value> struct list_caster {
+template <typename Type, typename Value>
+struct list_caster {
     using value_conv = make_caster<Value>;
 
     bool load(handle src, bool convert) {
@@ -143,7 +152,7 @@ template <typename Type, typename Value> struct list_caster {
 
 private:
     template <
-        typename T                                                                          = Type,
+        typename T = Type,
         enable_if_t<std::is_same<decltype(std::declval<T>().reserve(0)), void>::value, int> = 0>
     void reserve_maybe(const sequence &s, Type *) {
         value.reserve(s.size());
@@ -158,7 +167,8 @@ template <typename Type, typename Value> struct list_caster {
         list l(src.size());
         ssize_t index = 0;
         for (auto &&value : src) {
-            auto value_ = reinterpret_steal<object>(value_conv::cast(forward_like<T>(value), policy, parent));
+            auto value_ = reinterpret_steal<object>(
+                value_conv::cast(forward_like<T>(value), policy, parent));
             if (!value_)
                 return handle();
             PyList_SET_ITEM(l.ptr(), index++, value_.release().ptr()); // steals a reference
@@ -169,16 +179,17 @@ template <typename Type, typename Value> struct list_caster {
     PYBIND11_TYPE_CASTER(Type, const_name("List[") + value_conv::name + const_name("]"));
 };
 
-template <typename Type, typename Alloc> struct type_caster<std::vector<Type, Alloc>>
- : list_caster<std::vector<Type, Alloc>, Type> { };
+template <typename Type, typename Alloc>
+struct type_caster<std::vector<Type, Alloc>> : list_caster<std::vector<Type, Alloc>, Type> {};
 
-template <typename Type, typename Alloc> struct type_caster<std::deque<Type, Alloc>>
- : list_caster<std::deque<Type, Alloc>, Type> { };
+template <typename Type, typename Alloc>
+struct type_caster<std::deque<Type, Alloc>> : list_caster<std::deque<Type, Alloc>, Type> {};
 
-template <typename Type, typename Alloc> struct type_caster<std::list<Type, Alloc>>
- : list_caster<std::list<Type, Alloc>, Type> { };
+template <typename Type, typename Alloc>
+struct type_caster<std::list<Type, Alloc>> : list_caster<std::list<Type, Alloc>, Type> {};
 
-template <typename ArrayType, typename Value, bool Resizable, size_t Size = 0> struct array_caster {
+template <typename ArrayType, typename Value, bool Resizable, size_t Size = 0>
+struct array_caster {
     using value_conv = make_caster<Value>;
 
 private:
@@ -215,7 +226,8 @@ template <typename ArrayType, typename Value, bool Resizable, size_t Size = 0> s
         list l(src.size());
         ssize_t index = 0;
         for (auto &&value : src) {
-            auto value_ = reinterpret_steal<object>(value_conv::cast(forward_like<T>(value), policy, parent));
+            auto value_ = reinterpret_steal<object>(
+                value_conv::cast(forward_like<T>(value), policy, parent));
             if (!value_)
                 return handle();
             PyList_SET_ITEM(l.ptr(), index++, value_.release().ptr()); // steals a reference
@@ -223,29 +235,40 @@ template <typename ArrayType, typename Value, bool Resizable, size_t Size = 0> s
         return l.release();
     }
 
-    PYBIND11_TYPE_CASTER(ArrayType, const_name("List[") + value_conv::name + const_name<Resizable>(const_name(""), const_name("[") + const_name<Size>() + const_name("]")) + const_name("]"));
+    PYBIND11_TYPE_CASTER(ArrayType,
+                         const_name("List[") + value_conv::name
+                             + const_name<Resizable>(const_name(""),
+                                                     const_name("[") + const_name<Size>()
+                                                         + const_name("]"))
+                             + const_name("]"));
 };
 
-template <typename Type, size_t Size> struct type_caster<std::array<Type, Size>>
- : array_caster<std::array<Type, Size>, Type, false, Size> { };
+template <typename Type, size_t Size>
+struct type_caster<std::array<Type, Size>>
+    : array_caster<std::array<Type, Size>, Type, false, Size> {};
 
-template <typename Type> struct type_caster<std::valarray<Type>>
- : array_caster<std::valarray<Type>, Type, true> { };
+template <typename Type>
+struct type_caster<std::valarray<Type>> : array_caster<std::valarray<Type>, Type, true> {};
 
-template <typename Key, typename Compare, typename Alloc> struct type_caster<std::set<Key, Compare, Alloc>>
-  : set_caster<std::set<Key, Compare, Alloc>, Key> { };
+template <typename Key, typename Compare, typename Alloc>
+struct type_caster<std::set<Key, Compare, Alloc>>
+    : set_caster<std::set<Key, Compare, Alloc>, Key> {};
 
-template <typename Key, typename Hash, typename Equal, typename Alloc> struct type_caster<std::unordered_set<Key, Hash, Equal, Alloc>>
-  : set_caster<std::unordered_set<Key, Hash, Equal, Alloc>, Key> { };
+template <typename Key, typename Hash, typename Equal, typename Alloc>
+struct type_caster<std::unordered_set<Key, Hash, Equal, Alloc>>
+    : set_caster<std::unordered_set<Key, Hash, Equal, Alloc>, Key> {};
 
-template <typename Key, typename Value, typename Compare, typename Alloc> struct type_caster<std::map<Key, Value, Compare, Alloc>>
-  : map_caster<std::map<Key, Value, Compare, Alloc>, Key, Value> { };
+template <typename Key, typename Value, typename Compare, typename Alloc>
+struct type_caster<std::map<Key, Value, Compare, Alloc>>
+    : map_caster<std::map<Key, Value, Compare, Alloc>, Key, Value> {};
 
-template <typename Key, typename Value, typename Hash, typename Equal, typename Alloc> struct type_caster<std::unordered_map<Key, Value, Hash, Equal, Alloc>>
-  : map_caster<std::unordered_map<Key, Value, Hash, Equal, Alloc>, Key, Value> { };
+template <typename Key, typename Value, typename Hash, typename Equal, typename Alloc>
+struct type_caster<std::unordered_map<Key, Value, Hash, Equal, Alloc>>
+    : map_caster<std::unordered_map<Key, Value, Hash, Equal, Alloc>, Key, Value> {};
 
 // This type caster is intended to be used for std::optional and std::experimental::optional
-template<typename Type, typename Value = typename Type::value_type> struct optional_caster {
+template <typename Type, typename Value = typename Type::value_type>
+struct optional_caster {
     using value_conv = make_caster<Value>;
 
     template <typename T>
@@ -263,7 +286,7 @@ template<typename Type, typename Value = typename Type::value_type> struct optio
             return false;
         }
         if (src.is_none()) {
-            return true;  // default-constructed value is already empty
+            return true; // default-constructed value is already empty
         }
         value_conv inner_caster;
         if (!inner_caster.load(src, convert))
@@ -277,18 +300,20 @@ template<typename Type, typename Value = typename Type::value_type> struct optio
 };
 
 #if defined(PYBIND11_HAS_OPTIONAL)
-template<typename T> struct type_caster<std::optional<T>>
-    : public optional_caster<std::optional<T>> {};
+template <typename T>
+struct type_caster<std::optional<T>> : public optional_caster<std::optional<T>> {};
 
-template<> struct type_caster<std::nullopt_t>
-    : public void_caster<std::nullopt_t> {};
+template <>
+struct type_caster<std::nullopt_t> : public void_caster<std::nullopt_t> {};
 #endif
 
 #if defined(PYBIND11_HAS_EXP_OPTIONAL)
-template<typename T> struct type_caster<std::experimental::optional<T>>
+template <typename T>
+struct type_caster<std::experimental::optional<T>>
     : public optional_caster<std::experimental::optional<T>> {};
 
-template<> struct type_caster<std::experimental::nullopt_t>
+template <>
+struct type_caster<std::experimental::nullopt_t>
     : public void_caster<std::experimental::nullopt_t> {};
 #endif
 
@@ -309,7 +334,7 @@ struct variant_caster_visitor {
 /// `namespace::variant` types which provide a `namespace::visit()` function are handled here
 /// automatically using argument-dependent lookup. Users can provide specializations for other
 /// variant-like classes, e.g. `boost::variant` and `boost::apply_visitor`.
-template <template<typename...> class Variant>
+template <template <typename...> class Variant>
 struct visit_helper {
     template <typename... Args>
     static auto call(Args &&...args) -> decltype(visit(std::forward<Args>(args)...)) {
@@ -318,9 +343,10 @@ struct visit_helper {
 };
 
 /// Generic variant caster
-template <typename Variant> struct variant_caster;
+template <typename Variant>
+struct variant_caster;
 
-template <template<typename...> class V, typename... Ts>
+template <template <typename...> class V, typename... Ts>
 struct variant_caster<V<Ts...>> {
     static_assert(sizeof...(Ts) > 0, "Variant must consist of at least one alternative.");
 
@@ -353,12 +379,14 @@ struct variant_caster<V<Ts...>> {
     }
 
     using Type = V<Ts...>;
-    PYBIND11_TYPE_CASTER(Type, const_name("Union[") + detail::concat(make_caster<Ts>::name...) + const_name("]"));
+    PYBIND11_TYPE_CASTER(Type,
+                         const_name("Union[") + detail::concat(make_caster<Ts>::name...)
+                             + const_name("]"));
 };
 
 #if defined(PYBIND11_HAS_VARIANT)
 template <typename... Ts>
-struct type_caster<std::variant<Ts...>> : variant_caster<std::variant<Ts...>> { };
+struct type_caster<std::variant<Ts...>> : variant_caster<std::variant<Ts...>> {};
 #endif
 
 PYBIND11_NAMESPACE_END(detail)
diff --git a/include/pybind11/stl/filesystem.h b/include/pybind11/stl/filesystem.h
index a9a6c8512c..747992f51c 100644
--- a/include/pybind11/stl/filesystem.h
+++ b/include/pybind11/stl/filesystem.h
@@ -4,21 +4,20 @@
 
 #pragma once
 
-#include "../cast.h"
 #include "../pybind11.h"
-#include "../pytypes.h"
-
 #include "../detail/common.h"
 #include "../detail/descr.h"
+#include "../cast.h"
+#include "../pytypes.h"
 
 #include <string>
 
 #ifdef __has_include
-#  if defined(PYBIND11_CPP17) && __has_include(<filesystem>) && \
+#    if defined(PYBIND11_CPP17) && __has_include(<filesystem>) && \
       PY_VERSION_HEX >= 0x03060000
-#    include <filesystem>
-#    define PYBIND11_HAS_FILESYSTEM 1
-#  endif
+#        include <filesystem>
+#        define PYBIND11_HAS_FILESYSTEM 1
+#    endif
 #endif
 
 #if !defined(PYBIND11_HAS_FILESYSTEM) && !defined(PYBIND11_HAS_FILESYSTEM_IS_OPTIONAL)
@@ -30,28 +29,29 @@ PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 #if defined(PYBIND11_HAS_FILESYSTEM)
-template<typename T> struct path_caster {
+template <typename T>
+struct path_caster {
 
 private:
-    static PyObject* unicode_from_fs_native(const std::string& w) {
-#if !defined(PYPY_VERSION)
+    static PyObject *unicode_from_fs_native(const std::string &w) {
+#    if !defined(PYPY_VERSION)
         return PyUnicode_DecodeFSDefaultAndSize(w.c_str(), ssize_t(w.size()));
-#else
+#    else
         // PyPy mistakenly declares the first parameter as non-const.
-        return PyUnicode_DecodeFSDefaultAndSize(
-            const_cast<char*>(w.c_str()), ssize_t(w.size()));
-#endif
+        return PyUnicode_DecodeFSDefaultAndSize(const_cast<char *>(w.c_str()), ssize_t(w.size()));
+#    endif
     }
 
-    static PyObject* unicode_from_fs_native(const std::wstring& w) {
+    static PyObject *unicode_from_fs_native(const std::wstring &w) {
         return PyUnicode_FromWideChar(w.c_str(), ssize_t(w.size()));
     }
 
 public:
-    static handle cast(const T& path, return_value_policy, handle) {
+    static handle cast(const T &path, return_value_policy, handle) {
         if (auto py_str = unicode_from_fs_native(path.native())) {
-            return module_::import("pathlib").attr("Path")(reinterpret_steal<object>(py_str))
-                   .release();
+            return module_::import("pathlib")
+                .attr("Path")(reinterpret_steal<object>(py_str))
+                .release();
         }
         return nullptr;
     }
@@ -60,15 +60,15 @@ template<typename T> struct path_caster {
         // PyUnicode_FSConverter and PyUnicode_FSDecoder normally take care of
         // calling PyOS_FSPath themselves, but that's broken on PyPy (PyPy
         // issue #3168) so we do it ourselves instead.
-        PyObject* buf = PyOS_FSPath(handle.ptr());
+        PyObject *buf = PyOS_FSPath(handle.ptr());
         if (!buf) {
             PyErr_Clear();
             return false;
         }
-        PyObject* native = nullptr;
+        PyObject *native = nullptr;
         if constexpr (std::is_same_v<typename T::value_type, char>) {
             if (PyUnicode_FSConverter(buf, &native) != 0) {
-                if (auto c_str = PyBytes_AsString(native)) {
+                if (auto *c_str = PyBytes_AsString(native)) {
                     // AsString returns a pointer to the internal buffer, which
                     // must not be free'd.
                     value = c_str;
@@ -76,9 +76,9 @@ template<typename T> struct path_caster {
             }
         } else if constexpr (std::is_same_v<typename T::value_type, wchar_t>) {
             if (PyUnicode_FSDecoder(buf, &native) != 0) {
-                if (auto c_str = PyUnicode_AsWideCharString(native, nullptr)) {
+                if (auto *c_str = PyUnicode_AsWideCharString(native, nullptr)) {
                     // AsWideCharString returns a new string that must be free'd.
-                    value = c_str;  // Copies the string.
+                    value = c_str; // Copies the string.
                     PyMem_Free(c_str);
                 }
             }
@@ -95,8 +95,8 @@ template<typename T> struct path_caster {
     PYBIND11_TYPE_CASTER(T, const_name("os.PathLike"));
 };
 
-template<> struct type_caster<std::filesystem::path>
-    : public path_caster<std::filesystem::path> {};
+template <>
+struct type_caster<std::filesystem::path> : public path_caster<std::filesystem::path> {};
 #endif // PYBIND11_HAS_FILESYSTEM
 
 PYBIND11_NAMESPACE_END(detail)
diff --git a/include/pybind11/stl_bind.h b/include/pybind11/stl_bind.h
index 050be83cc5..a9f60fdec5 100644
--- a/include/pybind11/stl_bind.h
+++ b/include/pybind11/stl_bind.h
@@ -19,73 +19,87 @@ PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 /* SFINAE helper class used by 'is_comparable */
-template <typename T>  struct container_traits {
-    template <typename T2> static std::true_type test_comparable(decltype(std::declval<const T2 &>() == std::declval<const T2 &>())*);
-    template <typename T2> static std::false_type test_comparable(...);
-    template <typename T2> static std::true_type test_value(typename T2::value_type *);
-    template <typename T2> static std::false_type test_value(...);
-    template <typename T2> static std::true_type test_pair(typename T2::first_type *, typename T2::second_type *);
-    template <typename T2> static std::false_type test_pair(...);
-
-    static constexpr const bool is_comparable = std::is_same<std::true_type, decltype(test_comparable<T>(nullptr))>::value;
-    static constexpr const bool is_pair = std::is_same<std::true_type, decltype(test_pair<T>(nullptr, nullptr))>::value;
-    static constexpr const bool is_vector = std::is_same<std::true_type, decltype(test_value<T>(nullptr))>::value;
+template <typename T>
+struct container_traits {
+    template <typename T2>
+    static std::true_type
+    test_comparable(decltype(std::declval<const T2 &>() == std::declval<const T2 &>()) *);
+    template <typename T2>
+    static std::false_type test_comparable(...);
+    template <typename T2>
+    static std::true_type test_value(typename T2::value_type *);
+    template <typename T2>
+    static std::false_type test_value(...);
+    template <typename T2>
+    static std::true_type test_pair(typename T2::first_type *, typename T2::second_type *);
+    template <typename T2>
+    static std::false_type test_pair(...);
+
+    static constexpr const bool is_comparable
+        = std::is_same<std::true_type, decltype(test_comparable<T>(nullptr))>::value;
+    static constexpr const bool is_pair
+        = std::is_same<std::true_type, decltype(test_pair<T>(nullptr, nullptr))>::value;
+    static constexpr const bool is_vector
+        = std::is_same<std::true_type, decltype(test_value<T>(nullptr))>::value;
     static constexpr const bool is_element = !is_pair && !is_vector;
 };
 
 /* Default: is_comparable -> std::false_type */
 template <typename T, typename SFINAE = void>
-struct is_comparable : std::false_type { };
+struct is_comparable : std::false_type {};
 
 /* For non-map data structures, check whether operator== can be instantiated */
 template <typename T>
 struct is_comparable<
-    T, enable_if_t<container_traits<T>::is_element &&
-                   container_traits<T>::is_comparable>>
-    : std::true_type { };
+    T,
+    enable_if_t<container_traits<T>::is_element && container_traits<T>::is_comparable>>
+    : std::true_type {};
 
-/* For a vector/map data structure, recursively check the value type (which is std::pair for maps) */
+/* For a vector/map data structure, recursively check the value type (which is std::pair for maps)
+ */
 template <typename T>
 struct is_comparable<T, enable_if_t<container_traits<T>::is_vector>> {
-    static constexpr const bool value =
-        is_comparable<typename T::value_type>::value;
+    static constexpr const bool value = is_comparable<typename T::value_type>::value;
 };
 
 /* For pairs, recursively check the two data types */
 template <typename T>
 struct is_comparable<T, enable_if_t<container_traits<T>::is_pair>> {
-    static constexpr const bool value =
-        is_comparable<typename T::first_type>::value &&
-        is_comparable<typename T::second_type>::value;
+    static constexpr const bool value = is_comparable<typename T::first_type>::value
+                                        && is_comparable<typename T::second_type>::value;
 };
 
 /* Fallback functions */
-template <typename, typename, typename... Args> void vector_if_copy_constructible(const Args &...) { }
-template <typename, typename, typename... Args> void vector_if_equal_operator(const Args &...) { }
-template <typename, typename, typename... Args> void vector_if_insertion_operator(const Args &...) { }
-template <typename, typename, typename... Args> void vector_modifiers(const Args &...) { }
+template <typename, typename, typename... Args>
+void vector_if_copy_constructible(const Args &...) {}
+template <typename, typename, typename... Args>
+void vector_if_equal_operator(const Args &...) {}
+template <typename, typename, typename... Args>
+void vector_if_insertion_operator(const Args &...) {}
+template <typename, typename, typename... Args>
+void vector_modifiers(const Args &...) {}
 
-template<typename Vector, typename Class_>
+template <typename Vector, typename Class_>
 void vector_if_copy_constructible(enable_if_t<is_copy_constructible<Vector>::value, Class_> &cl) {
     cl.def(init<const Vector &>(), "Copy constructor");
 }
 
-template<typename Vector, typename Class_>
+template <typename Vector, typename Class_>
 void vector_if_equal_operator(enable_if_t<is_comparable<Vector>::value, Class_> &cl) {
     using T = typename Vector::value_type;
 
     cl.def(self == self);
     cl.def(self != self);
 
-    cl.def("count",
-        [](const Vector &v, const T &x) {
-            return std::count(v.begin(), v.end(), x);
-        },
+    cl.def(
+        "count",
+        [](const Vector &v, const T &x) { return std::count(v.begin(), v.end(), x); },
         arg("x"),
-        "Return the number of times ``x`` appears in the list"
-    );
+        "Return the number of times ``x`` appears in the list");
 
-    cl.def("remove", [](Vector &v, const T &x) {
+    cl.def(
+        "remove",
+        [](Vector &v, const T &x) {
             auto p = std::find(v.begin(), v.end(), x);
             if (p != v.end())
                 v.erase(p);
@@ -94,23 +108,21 @@ void vector_if_equal_operator(enable_if_t<is_comparable<Vector>::value, Class_>
         },
         arg("x"),
         "Remove the first item from the list whose value is x. "
-        "It is an error if there is no such item."
-    );
+        "It is an error if there is no such item.");
 
-    cl.def("__contains__",
-        [](const Vector &v, const T &x) {
-            return std::find(v.begin(), v.end(), x) != v.end();
-        },
+    cl.def(
+        "__contains__",
+        [](const Vector &v, const T &x) { return std::find(v.begin(), v.end(), x) != v.end(); },
         arg("x"),
-        "Return true the container contains ``x``"
-    );
+        "Return true the container contains ``x``");
 }
 
 // Vector modifiers -- requires a copyable vector_type:
-// (Technically, some of these (pop and __delitem__) don't actually require copyability, but it seems
-// silly to allow deletion but not insertion, so include them here too.)
+// (Technically, some of these (pop and __delitem__) don't actually require copyability, but it
+// seems silly to allow deletion but not insertion, so include them here too.)
 template <typename Vector, typename Class_>
-void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_type>::value, Class_> &cl) {
+void vector_modifiers(
+    enable_if_t<is_copy_constructible<typename Vector::value_type>::value, Class_> &cl) {
     using T = typename Vector::value_type;
     using SizeType = typename Vector::size_type;
     using DiffType = typename Vector::difference_type;
@@ -118,15 +130,16 @@ void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_t
     auto wrap_i = [](DiffType i, SizeType n) {
         if (i < 0)
             i += n;
-        if (i < 0 || (SizeType)i >= n)
+        if (i < 0 || (SizeType) i >= n)
             throw index_error();
         return i;
     };
 
-    cl.def("append",
-           [](Vector &v, const T &value) { v.push_back(value); },
-           arg("x"),
-           "Add an item to the end of the list");
+    cl.def(
+        "append",
+        [](Vector &v, const T &value) { v.push_back(value); },
+        arg("x"),
+        "Add an item to the end of the list");
 
     cl.def(init([](const iterable &it) {
         auto v = std::unique_ptr<Vector>(new Vector());
@@ -136,20 +149,14 @@ void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_t
         return v.release();
     }));
 
-    cl.def("clear",
-        [](Vector &v) {
-            v.clear();
-        },
-        "Clear the contents"
-    );
+    cl.def(
+        "clear", [](Vector &v) { v.clear(); }, "Clear the contents");
 
-    cl.def("extend",
-       [](Vector &v, const Vector &src) {
-           v.insert(v.end(), src.begin(), src.end());
-       },
-       arg("L"),
-       "Extend the list by appending all the items in the given list"
-    );
+    cl.def(
+        "extend",
+        [](Vector &v, const Vector &src) { v.insert(v.end(), src.begin(), src.end()); },
+        arg("L"),
+        "Extend the list by appending all the items in the given list");
 
     cl.def(
         "extend",
@@ -174,20 +181,22 @@ void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_t
         arg("L"),
         "Extend the list by appending all the items in the given list");
 
-    cl.def("insert",
+    cl.def(
+        "insert",
         [](Vector &v, DiffType i, const T &x) {
             // Can't use wrap_i; i == v.size() is OK
             if (i < 0)
                 i += v.size();
-            if (i < 0 || (SizeType)i > v.size())
+            if (i < 0 || (SizeType) i > v.size())
                 throw index_error();
             v.insert(v.begin() + i, x);
         },
-        arg("i") , arg("x"),
-        "Insert an item at a given position."
-    );
+        arg("i"),
+        arg("x"),
+        "Insert an item at a given position.");
 
-    cl.def("pop",
+    cl.def(
+        "pop",
         [](Vector &v) {
             if (v.empty())
                 throw index_error();
@@ -195,10 +204,10 @@ void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_t
             v.pop_back();
             return t;
         },
-        "Remove and return the last item"
-    );
+        "Remove and return the last item");
 
-    cl.def("pop",
+    cl.def(
+        "pop",
         [wrap_i](Vector &v, DiffType i) {
             i = wrap_i(i, v.size());
             T t = std::move(v[(SizeType) i]);
@@ -206,15 +215,12 @@ void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_t
             return t;
         },
         arg("i"),
-        "Remove and return the item at index ``i``"
-    );
+        "Remove and return the item at index ``i``");
 
-    cl.def("__setitem__",
-        [wrap_i](Vector &v, DiffType i, const T &t) {
-            i = wrap_i(i, v.size());
-            v[(SizeType)i] = t;
-        }
-    );
+    cl.def("__setitem__", [wrap_i](Vector &v, DiffType i, const T &t) {
+        i = wrap_i(i, v.size());
+        v[(SizeType) i] = t;
+    });
 
     /// Slicing protocol
     cl.def(
@@ -228,7 +234,7 @@ void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_t
             auto *seq = new Vector();
             seq->reserve((size_t) slicelength);
 
-            for (size_t i=0; i<slicelength; ++i) {
+            for (size_t i = 0; i < slicelength; ++i) {
                 seq->push_back(v[start]);
                 start += step;
             }
@@ -245,22 +251,23 @@ void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_t
                 throw error_already_set();
 
             if (slicelength != value.size())
-                throw std::runtime_error("Left and right hand size of slice assignment have different sizes!");
+                throw std::runtime_error(
+                    "Left and right hand size of slice assignment have different sizes!");
 
-            for (size_t i=0; i<slicelength; ++i) {
+            for (size_t i = 0; i < slicelength; ++i) {
                 v[start] = value[i];
                 start += step;
             }
         },
         "Assign list elements using a slice object");
 
-    cl.def("__delitem__",
+    cl.def(
+        "__delitem__",
         [wrap_i](Vector &v, DiffType i) {
             i = wrap_i(i, v.size());
             v.erase(v.begin() + i);
         },
-        "Delete the list elements at index ``i``"
-    );
+        "Delete the list elements at index ``i``");
 
     cl.def(
         "__delitem__",
@@ -284,8 +291,10 @@ void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_t
 
 // If the type has an operator[] that doesn't return a reference (most notably std::vector<bool>),
 // we have to access by copying; otherwise we return by reference.
-template <typename Vector> using vector_needs_copy = negation<
-    std::is_same<decltype(std::declval<Vector>()[typename Vector::size_type()]), typename Vector::value_type &>>;
+template <typename Vector>
+using vector_needs_copy
+    = negation<std::is_same<decltype(std::declval<Vector>()[typename Vector::size_type()]),
+                            typename Vector::value_type &>>;
 
 // The usual case: access and iterate by reference
 template <typename Vector, typename Class_>
@@ -293,31 +302,32 @@ void vector_accessor(enable_if_t<!vector_needs_copy<Vector>::value, Class_> &cl)
     using T = typename Vector::value_type;
     using SizeType = typename Vector::size_type;
     using DiffType = typename Vector::difference_type;
-    using ItType   = typename Vector::iterator;
+    using ItType = typename Vector::iterator;
 
     auto wrap_i = [](DiffType i, SizeType n) {
         if (i < 0)
             i += n;
-        if (i < 0 || (SizeType)i >= n)
+        if (i < 0 || (SizeType) i >= n)
             throw index_error();
         return i;
     };
 
-    cl.def("__getitem__",
+    cl.def(
+        "__getitem__",
         [wrap_i](Vector &v, DiffType i) -> T & {
             i = wrap_i(i, v.size());
-            return v[(SizeType)i];
+            return v[(SizeType) i];
         },
         return_value_policy::reference_internal // ref + keepalive
     );
 
-    cl.def("__iter__",
-           [](Vector &v) {
-               return make_iterator<
-                   return_value_policy::reference_internal, ItType, ItType, T&>(
-                   v.begin(), v.end());
-           },
-           keep_alive<0, 1>() /* Essential: keep list alive while iterator exists */
+    cl.def(
+        "__iter__",
+        [](Vector &v) {
+            return make_iterator<return_value_policy::reference_internal, ItType, ItType, T &>(
+                v.begin(), v.end());
+        },
+        keep_alive<0, 1>() /* Essential: keep list alive while iterator exists */
     );
 }
 
@@ -327,36 +337,36 @@ void vector_accessor(enable_if_t<vector_needs_copy<Vector>::value, Class_> &cl)
     using T = typename Vector::value_type;
     using SizeType = typename Vector::size_type;
     using DiffType = typename Vector::difference_type;
-    using ItType   = typename Vector::iterator;
-    cl.def("__getitem__",
-        [](const Vector &v, DiffType i) -> T {
-            if (i < 0 && (i += v.size()) < 0)
-                throw index_error();
-            if ((SizeType)i >= v.size())
-                throw index_error();
-            return v[(SizeType)i];
-        }
-    );
+    using ItType = typename Vector::iterator;
+    cl.def("__getitem__", [](const Vector &v, DiffType i) -> T {
+        if (i < 0 && (i += v.size()) < 0)
+            throw index_error();
+        if ((SizeType) i >= v.size())
+            throw index_error();
+        return v[(SizeType) i];
+    });
 
-    cl.def("__iter__",
-           [](Vector &v) {
-               return make_iterator<
-                   return_value_policy::copy, ItType, ItType, T>(
-                   v.begin(), v.end());
-           },
-           keep_alive<0, 1>() /* Essential: keep list alive while iterator exists */
+    cl.def(
+        "__iter__",
+        [](Vector &v) {
+            return make_iterator<return_value_policy::copy, ItType, ItType, T>(v.begin(), v.end());
+        },
+        keep_alive<0, 1>() /* Essential: keep list alive while iterator exists */
     );
 }
 
-template <typename Vector, typename Class_> auto vector_if_insertion_operator(Class_ &cl, std::string const &name)
-    -> decltype(std::declval<std::ostream&>() << std::declval<typename Vector::value_type>(), void()) {
+template <typename Vector, typename Class_>
+auto vector_if_insertion_operator(Class_ &cl, std::string const &name)
+    -> decltype(std::declval<std::ostream &>() << std::declval<typename Vector::value_type>(),
+                void()) {
     using size_type = typename Vector::size_type;
 
-    cl.def("__repr__",
-           [name](Vector &v) {
+    cl.def(
+        "__repr__",
+        [name](Vector &v) {
             std::ostringstream s;
             s << name << '[';
-            for (size_type i=0; i < v.size(); ++i) {
+            for (size_type i = 0; i < v.size(); ++i) {
                 s << v[i];
                 if (i != v.size() - 1)
                     s << ", ";
@@ -364,16 +374,20 @@ template <typename Vector, typename Class_> auto vector_if_insertion_operator(Cl
             s << ']';
             return s.str();
         },
-        "Return the canonical string representation of this list."
-    );
+        "Return the canonical string representation of this list.");
 }
 
 // Provide the buffer interface for vectors if we have data() and we have a format for it
-// GCC seems to have "void std::vector<bool>::data()" - doing SFINAE on the existence of data() is insufficient, we need to check it returns an appropriate pointer
+// GCC seems to have "void std::vector<bool>::data()" - doing SFINAE on the existence of data() is
+// insufficient, we need to check it returns an appropriate pointer
 template <typename Vector, typename = void>
 struct vector_has_data_and_format : std::false_type {};
 template <typename Vector>
-struct vector_has_data_and_format<Vector, enable_if_t<std::is_same<decltype(format_descriptor<typename Vector::value_type>::format(), std::declval<Vector>().data()), typename Vector::value_type*>::value>> : std::true_type {};
+struct vector_has_data_and_format<
+    Vector,
+    enable_if_t<std::is_same<decltype(format_descriptor<typename Vector::value_type>::format(),
+                                      std::declval<Vector>().data()),
+                             typename Vector::value_type *>::value>> : std::true_type {};
 
 // [workaround(intel)] Separate function required here
 // Workaround as the Intel compiler does not compile the enable_if_t part below
@@ -388,16 +402,23 @@ constexpr bool args_any_are_buffer() {
 
 // Add the buffer interface to a vector
 template <typename Vector, typename Class_, typename... Args>
-void vector_buffer_impl(Class_& cl, std::true_type) {
+void vector_buffer_impl(Class_ &cl, std::true_type) {
     using T = typename Vector::value_type;
 
-    static_assert(vector_has_data_and_format<Vector>::value, "There is not an appropriate format descriptor for this vector");
+    static_assert(vector_has_data_and_format<Vector>::value,
+                  "There is not an appropriate format descriptor for this vector");
 
-    // numpy.h declares this for arbitrary types, but it may raise an exception and crash hard at runtime if PYBIND11_NUMPY_DTYPE hasn't been called, so check here
+    // numpy.h declares this for arbitrary types, but it may raise an exception and crash hard at
+    // runtime if PYBIND11_NUMPY_DTYPE hasn't been called, so check here
     format_descriptor<T>::format();
 
-    cl.def_buffer([](Vector& v) -> buffer_info {
-        return buffer_info(v.data(), static_cast<ssize_t>(sizeof(T)), format_descriptor<T>::format(), 1, {v.size()}, {sizeof(T)});
+    cl.def_buffer([](Vector &v) -> buffer_info {
+        return buffer_info(v.data(),
+                           static_cast<ssize_t>(sizeof(T)),
+                           format_descriptor<T>::format(),
+                           1,
+                           {v.size()},
+                           {sizeof(T)});
     });
 
     cl.def(init([](const buffer &buf) {
@@ -405,9 +426,10 @@ void vector_buffer_impl(Class_& cl, std::true_type) {
         if (info.ndim != 1 || info.strides[0] % static_cast<ssize_t>(sizeof(T)))
             throw type_error("Only valid 1D buffers can be copied to a vector");
         if (!detail::compare_buffer_info<T>::compare(info) || (ssize_t) sizeof(T) != info.itemsize)
-            throw type_error("Format mismatch (Python: " + info.format + " C++: " + format_descriptor<T>::format() + ")");
+            throw type_error("Format mismatch (Python: " + info.format
+                             + " C++: " + format_descriptor<T>::format() + ")");
 
-        T *p = static_cast<T*>(info.ptr);
+        T *p = static_cast<T *>(info.ptr);
         ssize_t step = info.strides[0] / static_cast<ssize_t>(sizeof(T));
         T *end = p + info.shape[0] * step;
         if (step == 1) {
@@ -418,18 +440,18 @@ void vector_buffer_impl(Class_& cl, std::true_type) {
         for (; p != end; p += step)
             vec.push_back(*p);
         return vec;
-
     }));
 
     return;
 }
 
 template <typename Vector, typename Class_, typename... Args>
-void vector_buffer_impl(Class_&, std::false_type) {}
+void vector_buffer_impl(Class_ &, std::false_type) {}
 
 template <typename Vector, typename Class_, typename... Args>
-void vector_buffer(Class_& cl) {
-    vector_buffer_impl<Vector, Class_, Args...>(cl, detail::any_of<std::is_same<Args, buffer_protocol>...>{});
+void vector_buffer(Class_ &cl) {
+    vector_buffer_impl<Vector, Class_, Args...>(
+        cl, detail::any_of<std::is_same<Args, buffer_protocol>...>{});
 }
 
 PYBIND11_NAMESPACE_END(detail)
@@ -438,13 +460,13 @@ PYBIND11_NAMESPACE_END(detail)
 // std::vector
 //
 template <typename Vector, typename holder_type = std::unique_ptr<Vector>, typename... Args>
-class_<Vector, holder_type> bind_vector(handle scope, std::string const &name, Args&&... args) {
+class_<Vector, holder_type> bind_vector(handle scope, std::string const &name, Args &&...args) {
     using Class_ = class_<Vector, holder_type>;
 
     // If the value_type is unregistered (e.g. a converting type) or is itself registered
     // module-local then make the vector binding module-local as well:
     using vtype = typename Vector::value_type;
-    auto vtype_info = detail::get_type_info(typeid(vtype));
+    auto *vtype_info = detail::get_type_info(typeid(vtype));
     bool local = !vtype_info || vtype_info->module_local;
 
     Class_ cl(scope, name.c_str(), pybind11::module_local(local), std::forward<Args>(args)...);
@@ -469,18 +491,13 @@ class_<Vector, holder_type> bind_vector(handle scope, std::string const &name, A
     // Accessor and iterator; return by value if copyable, otherwise we return by ref + keep-alive
     detail::vector_accessor<Vector, Class_>(cl);
 
-    cl.def("__bool__",
-        [](const Vector &v) -> bool {
-            return !v.empty();
-        },
-        "Check whether the list is nonempty"
-    );
+    cl.def(
+        "__bool__",
+        [](const Vector &v) -> bool { return !v.empty(); },
+        "Check whether the list is nonempty");
 
     cl.def("__len__", &Vector::size);
 
-
-
-
 #if 0
     // C++ style functions deprecated, leaving it here as an example
     cl.def(init<size_type>());
@@ -524,8 +541,6 @@ class_<Vector, holder_type> bind_vector(handle scope, std::string const &name, A
     return cl;
 }
 
-
-
 //
 // std::map, std::unordered_map
 //
@@ -533,52 +548,57 @@ class_<Vector, holder_type> bind_vector(handle scope, std::string const &name, A
 PYBIND11_NAMESPACE_BEGIN(detail)
 
 /* Fallback functions */
-template <typename, typename, typename... Args> void map_if_insertion_operator(const Args &...) { }
-template <typename, typename, typename... Args> void map_assignment(const Args &...) { }
+template <typename, typename, typename... Args>
+void map_if_insertion_operator(const Args &...) {}
+template <typename, typename, typename... Args>
+void map_assignment(const Args &...) {}
 
 // Map assignment when copy-assignable: just copy the value
 template <typename Map, typename Class_>
-void map_assignment(enable_if_t<is_copy_assignable<typename Map::mapped_type>::value, Class_> &cl) {
+void map_assignment(
+    enable_if_t<is_copy_assignable<typename Map::mapped_type>::value, Class_> &cl) {
     using KeyType = typename Map::key_type;
     using MappedType = typename Map::mapped_type;
 
-    cl.def("__setitem__",
-           [](Map &m, const KeyType &k, const MappedType &v) {
-               auto it = m.find(k);
-               if (it != m.end()) it->second = v;
-               else m.emplace(k, v);
-           }
-    );
+    cl.def("__setitem__", [](Map &m, const KeyType &k, const MappedType &v) {
+        auto it = m.find(k);
+        if (it != m.end())
+            it->second = v;
+        else
+            m.emplace(k, v);
+    });
 }
 
-// Not copy-assignable, but still copy-constructible: we can update the value by erasing and reinserting
-template<typename Map, typename Class_>
-void map_assignment(enable_if_t<
-        !is_copy_assignable<typename Map::mapped_type>::value &&
-        is_copy_constructible<typename Map::mapped_type>::value,
-        Class_> &cl) {
+// Not copy-assignable, but still copy-constructible: we can update the value by erasing and
+// reinserting
+template <typename Map, typename Class_>
+void map_assignment(enable_if_t<!is_copy_assignable<typename Map::mapped_type>::value
+                                    && is_copy_constructible<typename Map::mapped_type>::value,
+                                Class_> &cl) {
     using KeyType = typename Map::key_type;
     using MappedType = typename Map::mapped_type;
 
-    cl.def("__setitem__",
-           [](Map &m, const KeyType &k, const MappedType &v) {
-               // We can't use m[k] = v; because value type might not be default constructable
-               auto r = m.emplace(k, v);
-               if (!r.second) {
-                   // value type is not copy assignable so the only way to insert it is to erase it first...
-                   m.erase(r.first);
-                   m.emplace(k, v);
-               }
-           }
-    );
+    cl.def("__setitem__", [](Map &m, const KeyType &k, const MappedType &v) {
+        // We can't use m[k] = v; because value type might not be default constructable
+        auto r = m.emplace(k, v);
+        if (!r.second) {
+            // value type is not copy assignable so the only way to insert it is to erase it
+            // first...
+            m.erase(r.first);
+            m.emplace(k, v);
+        }
+    });
 }
 
+template <typename Map, typename Class_>
+auto map_if_insertion_operator(Class_ &cl, std::string const &name)
+    -> decltype(std::declval<std::ostream &>() << std::declval<typename Map::key_type>()
+                                               << std::declval<typename Map::mapped_type>(),
+                void()) {
 
-template <typename Map, typename Class_> auto map_if_insertion_operator(Class_ &cl, std::string const &name)
--> decltype(std::declval<std::ostream&>() << std::declval<typename Map::key_type>() << std::declval<typename Map::mapped_type>(), void()) {
-
-    cl.def("__repr__",
-           [name](Map &m) {
+    cl.def(
+        "__repr__",
+        [name](Map &m) {
             std::ostringstream s;
             s << name << '{';
             bool f = false;
@@ -591,32 +611,28 @@ template <typename Map, typename Class_> auto map_if_insertion_operator(Class_ &
             s << '}';
             return s.str();
         },
-        "Return the canonical string representation of this map."
-    );
+        "Return the canonical string representation of this map.");
 }
 
-template<typename Map>
-struct keys_view
-{
+template <typename Map>
+struct keys_view {
     Map &map;
 };
 
-template<typename Map>
-struct values_view
-{
+template <typename Map>
+struct values_view {
     Map &map;
 };
 
-template<typename Map>
-struct items_view
-{
+template <typename Map>
+struct items_view {
     Map &map;
 };
 
 PYBIND11_NAMESPACE_END(detail)
 
 template <typename Map, typename holder_type = std::unique_ptr<Map>, typename... Args>
-class_<Map, holder_type> bind_map(handle scope, const std::string &name, Args&&... args) {
+class_<Map, holder_type> bind_map(handle scope, const std::string &name, Args &&...args) {
     using KeyType = typename Map::key_type;
     using MappedType = typename Map::mapped_type;
     using KeysView = detail::keys_view<Map>;
@@ -627,7 +643,7 @@ class_<Map, holder_type> bind_map(handle scope, const std::string &name, Args&&.
     // If either type is a non-module-local bound type then make the map binding non-local as well;
     // otherwise (e.g. both types are either module-local or converting) the map will be
     // module-local.
-    auto tinfo = detail::get_type_info(typeid(MappedType));
+    auto *tinfo = detail::get_type_info(typeid(MappedType));
     bool local = !tinfo || tinfo->module_local;
     if (local) {
         tinfo = detail::get_type_info(typeid(KeyType));
@@ -647,97 +663,93 @@ class_<Map, holder_type> bind_map(handle scope, const std::string &name, Args&&.
     // Register stream insertion operator (if possible)
     detail::map_if_insertion_operator<Map, Class_>(cl, name);
 
-    cl.def("__bool__",
+    cl.def(
+        "__bool__",
         [](const Map &m) -> bool { return !m.empty(); },
-        "Check whether the map is nonempty"
-    );
+        "Check whether the map is nonempty");
 
-    cl.def("__iter__",
-           [](Map &m) { return make_key_iterator(m.begin(), m.end()); },
-           keep_alive<0, 1>() /* Essential: keep map alive while iterator exists */
+    cl.def(
+        "__iter__",
+        [](Map &m) { return make_key_iterator(m.begin(), m.end()); },
+        keep_alive<0, 1>() /* Essential: keep map alive while iterator exists */
     );
 
-    cl.def("keys",
-           [](Map &m) { return KeysView{m}; },
-           keep_alive<0, 1>() /* Essential: keep map alive while view exists */
+    cl.def(
+        "keys",
+        [](Map &m) { return KeysView{m}; },
+        keep_alive<0, 1>() /* Essential: keep map alive while view exists */
     );
 
-    cl.def("values",
-           [](Map &m) { return ValuesView{m}; },
-           keep_alive<0, 1>() /* Essential: keep map alive while view exists */
+    cl.def(
+        "values",
+        [](Map &m) { return ValuesView{m}; },
+        keep_alive<0, 1>() /* Essential: keep map alive while view exists */
     );
 
-    cl.def("items",
-           [](Map &m) { return ItemsView{m}; },
-           keep_alive<0, 1>() /* Essential: keep map alive while view exists */
+    cl.def(
+        "items",
+        [](Map &m) { return ItemsView{m}; },
+        keep_alive<0, 1>() /* Essential: keep map alive while view exists */
     );
 
-    cl.def("__getitem__",
+    cl.def(
+        "__getitem__",
         [](Map &m, const KeyType &k) -> MappedType & {
             auto it = m.find(k);
             if (it == m.end())
-              throw key_error();
-           return it->second;
+                throw key_error();
+            return it->second;
         },
         return_value_policy::reference_internal // ref + keepalive
     );
 
-    cl.def("__contains__",
-        [](Map &m, const KeyType &k) -> bool {
-            auto it = m.find(k);
-            if (it == m.end())
-              return false;
-           return true;
-        }
-    );
+    cl.def("__contains__", [](Map &m, const KeyType &k) -> bool {
+        auto it = m.find(k);
+        if (it == m.end())
+            return false;
+        return true;
+    });
     // Fallback for when the object is not of the key type
     cl.def("__contains__", [](Map &, const object &) -> bool { return false; });
 
     // Assignment provided only if the type is copyable
     detail::map_assignment<Map, Class_>(cl);
 
-    cl.def("__delitem__",
-           [](Map &m, const KeyType &k) {
-               auto it = m.find(k);
-               if (it == m.end())
-                   throw key_error();
-               m.erase(it);
-           }
-    );
+    cl.def("__delitem__", [](Map &m, const KeyType &k) {
+        auto it = m.find(k);
+        if (it == m.end())
+            throw key_error();
+        m.erase(it);
+    });
 
     cl.def("__len__", &Map::size);
 
     keys_view.def("__len__", [](KeysView &view) { return view.map.size(); });
-    keys_view.def("__iter__",
-        [](KeysView &view) {
-            return make_key_iterator(view.map.begin(), view.map.end());
-        },
+    keys_view.def(
+        "__iter__",
+        [](KeysView &view) { return make_key_iterator(view.map.begin(), view.map.end()); },
         keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
     );
-    keys_view.def("__contains__",
-        [](KeysView &view, const KeyType &k) -> bool {
-            auto it = view.map.find(k);
-            if (it == view.map.end())
-                return false;
-            return true;
-        }
-    );
+    keys_view.def("__contains__", [](KeysView &view, const KeyType &k) -> bool {
+        auto it = view.map.find(k);
+        if (it == view.map.end())
+            return false;
+        return true;
+    });
     // Fallback for when the object is not of the key type
     keys_view.def("__contains__", [](KeysView &, const object &) -> bool { return false; });
 
     values_view.def("__len__", [](ValuesView &view) { return view.map.size(); });
-    values_view.def("__iter__",
-        [](ValuesView &view) {
-            return make_value_iterator(view.map.begin(), view.map.end());
-        },
+    values_view.def(
+        "__iter__",
+        [](ValuesView &view) { return make_value_iterator(view.map.begin(), view.map.end()); },
         keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
     );
 
     items_view.def("__len__", [](ItemsView &view) { return view.map.size(); });
-    items_view.def("__iter__",
-        [](ItemsView &view) {
-            return make_iterator(view.map.begin(), view.map.end());
-        },
+    items_view.def(
+        "__iter__",
+        [](ItemsView &view) { return make_iterator(view.map.begin(), view.map.end()); },
         keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
     );
 
diff --git a/tests/constructor_stats.h b/tests/constructor_stats.h
index 805968a09b..8693e30310 100644
--- a/tests/constructor_stats.h
+++ b/tests/constructor_stats.h
@@ -56,7 +56,8 @@ from the ConstructorStats instance `.values()` method.
 In some cases, when you need to track instances of a C++ class not registered with pybind11, you
 need to add a function returning the ConstructorStats for the C++ class; this can be done with:
 
-    m.def("get_special_cstats", &ConstructorStats::get<SpecialClass>, py::return_value_policy::reference)
+    m.def("get_special_cstats", &ConstructorStats::get<SpecialClass>,
+py::return_value_policy::reference)
 
 Finally, you can suppress the output messages, but keep the constructor tracking (for
 inspection/testing in python) by using the functions with `print_` replaced with `track_` (e.g.
@@ -65,14 +66,16 @@ inspection/testing in python) by using the functions with `print_` replaced with
 */
 
 #include "pybind11_tests.h"
-#include <unordered_map>
+
 #include <list>
-#include <typeindex>
 #include <sstream>
+#include <typeindex>
+#include <unordered_map>
 
 class ConstructorStats {
 protected:
-    std::unordered_map<void*, int> _instances; // Need a map rather than set because members can shared address with parents
+    std::unordered_map<void *, int>
+        _instances; // Need a map rather than set because members can shared address with parents
     std::list<std::string> _values; // Used to track values (e.g. of value constructors)
 public:
     int default_constructions = 0;
@@ -96,9 +99,7 @@ class ConstructorStats {
         default_constructions++;
     }
 
-    void created(void *inst) {
-        ++_instances[inst];
-    }
+    void created(void *inst) { ++_instances[inst]; }
 
     void destroyed(void *inst) {
         if (--_instances[inst] < 0)
@@ -111,11 +112,12 @@ class ConstructorStats {
         // Force garbage collection to ensure any pending destructors are invoked:
 #if defined(PYPY_VERSION)
         PyObject *globals = PyEval_GetGlobals();
-        PyObject *result = PyRun_String(
-            "import gc\n"
-            "for i in range(2):"
-            "    gc.collect()\n",
-            Py_file_input, globals, globals);
+        PyObject *result = PyRun_String("import gc\n"
+                                        "for i in range(2):"
+                                        "    gc.collect()\n",
+                                        Py_file_input,
+                                        globals,
+                                        globals);
         if (result == nullptr)
             throw py::error_already_set();
         Py_DECREF(result);
@@ -135,7 +137,8 @@ class ConstructorStats {
 
     void value() {} // Recursion terminator
     // Takes one or more values, converts them to strings, then stores them.
-    template <typename T, typename... Tmore> void value(const T &v, Tmore &&...args) {
+    template <typename T, typename... Tmore>
+    void value(const T &v, Tmore &&...args) {
         std::ostringstream oss;
         oss << v;
         _values.push_back(oss.str());
@@ -145,19 +148,21 @@ class ConstructorStats {
     // Move out stored values
     py::list values() {
         py::list l;
-        for (const auto &v : _values) l.append(py::cast(v));
+        for (const auto &v : _values)
+            l.append(py::cast(v));
         _values.clear();
         return l;
     }
 
     // Gets constructor stats from a C++ type index
-    static ConstructorStats& get(std::type_index type) {
+    static ConstructorStats &get(std::type_index type) {
         static std::unordered_map<std::type_index, ConstructorStats> all_cstats;
         return all_cstats[type];
     }
 
     // Gets constructor stats from a C++ type
-    template <typename T> static ConstructorStats& get() {
+    template <typename T>
+    static ConstructorStats &get() {
 #if defined(PYPY_VERSION)
         gc();
 #endif
@@ -165,11 +170,12 @@ class ConstructorStats {
     }
 
     // Gets constructor stats from a Python class
-    static ConstructorStats& get(py::object class_) {
+    static ConstructorStats &get(py::object class_) {
         auto &internals = py::detail::get_internals();
         const std::type_index *t1 = nullptr, *t2 = nullptr;
         try {
-            auto *type_info = internals.registered_types_py.at((PyTypeObject *) class_.ptr()).at(0);
+            auto *type_info
+                = internals.registered_types_py.at((PyTypeObject *) class_.ptr()).at(0);
             for (auto &p : internals.registered_types_cpp) {
                 if (p.second == type_info) {
                     if (t1) {
@@ -179,17 +185,21 @@ class ConstructorStats {
                     t1 = &p.first;
                 }
             }
+        } catch (const std::out_of_range &) {
         }
-        catch (const std::out_of_range&) {}
-        if (!t1) throw std::runtime_error("Unknown class passed to ConstructorStats::get()");
+        if (!t1)
+            throw std::runtime_error("Unknown class passed to ConstructorStats::get()");
         auto &cs1 = get(*t1);
-        // If we have both a t1 and t2 match, one is probably the trampoline class; return whichever
-        // has more constructions (typically one or the other will be 0)
+        // If we have both a t1 and t2 match, one is probably the trampoline class; return
+        // whichever has more constructions (typically one or the other will be 0)
         if (t2) {
             auto &cs2 = get(*t2);
-            int cs1_total = cs1.default_constructions + cs1.copy_constructions + cs1.move_constructions + (int) cs1._values.size();
-            int cs2_total = cs2.default_constructions + cs2.copy_constructions + cs2.move_constructions + (int) cs2._values.size();
-            if (cs2_total > cs1_total) return cs2;
+            int cs1_total = cs1.default_constructions + cs1.copy_constructions
+                            + cs1.move_constructions + (int) cs1._values.size();
+            int cs2_total = cs2.default_constructions + cs2.copy_constructions
+                            + cs2.move_constructions + (int) cs2._values.size();
+            if (cs2_total > cs1_total)
+                return cs2;
         }
         return cs1;
     }
@@ -198,78 +208,108 @@ class ConstructorStats {
 // To track construction/destruction, you need to call these methods from the various
 // constructors/operators.  The ones that take extra values record the given values in the
 // constructor stats values for later inspection.
-template <class T> void track_copy_created(T *inst) { ConstructorStats::get<T>().copy_created(inst); }
-template <class T> void track_move_created(T *inst) { ConstructorStats::get<T>().move_created(inst); }
-template <class T, typename... Values> void track_copy_assigned(T *, Values &&...values) {
+template <class T>
+void track_copy_created(T *inst) {
+    ConstructorStats::get<T>().copy_created(inst);
+}
+template <class T>
+void track_move_created(T *inst) {
+    ConstructorStats::get<T>().move_created(inst);
+}
+template <class T, typename... Values>
+void track_copy_assigned(T *, Values &&...values) {
     auto &cst = ConstructorStats::get<T>();
     cst.copy_assignments++;
     cst.value(std::forward<Values>(values)...);
 }
-template <class T, typename... Values> void track_move_assigned(T *, Values &&...values) {
+template <class T, typename... Values>
+void track_move_assigned(T *, Values &&...values) {
     auto &cst = ConstructorStats::get<T>();
     cst.move_assignments++;
     cst.value(std::forward<Values>(values)...);
 }
-template <class T, typename... Values> void track_default_created(T *inst, Values &&...values) {
+template <class T, typename... Values>
+void track_default_created(T *inst, Values &&...values) {
     auto &cst = ConstructorStats::get<T>();
     cst.default_created(inst);
     cst.value(std::forward<Values>(values)...);
 }
-template <class T, typename... Values> void track_created(T *inst, Values &&...values) {
+template <class T, typename... Values>
+void track_created(T *inst, Values &&...values) {
     auto &cst = ConstructorStats::get<T>();
     cst.created(inst);
     cst.value(std::forward<Values>(values)...);
 }
-template <class T, typename... Values> void track_destroyed(T *inst) {
+template <class T, typename... Values>
+void track_destroyed(T *inst) {
     ConstructorStats::get<T>().destroyed(inst);
 }
-template <class T, typename... Values> void track_values(T *, Values &&...values) {
+template <class T, typename... Values>
+void track_values(T *, Values &&...values) {
     ConstructorStats::get<T>().value(std::forward<Values>(values)...);
 }
 
 /// Don't cast pointers to Python, print them as strings
 inline const char *format_ptrs(const char *p) { return p; }
 template <typename T>
-py::str format_ptrs(T *p) { return "{:#x}"_s.format(reinterpret_cast<std::uintptr_t>(p)); }
+py::str format_ptrs(T *p) {
+    return "{:#x}"_s.format(reinterpret_cast<std::uintptr_t>(p));
+}
 template <typename T>
-auto format_ptrs(T &&x) -> decltype(std::forward<T>(x)) { return std::forward<T>(x); }
+auto format_ptrs(T &&x) -> decltype(std::forward<T>(x)) {
+    return std::forward<T>(x);
+}
 
 template <class T, typename... Output>
 void print_constr_details(T *inst, const std::string &action, Output &&...output) {
-    py::print("###", py::type_id<T>(), "@", format_ptrs(inst), action,
+    py::print("###",
+              py::type_id<T>(),
+              "@",
+              format_ptrs(inst),
+              action,
               format_ptrs(std::forward<Output>(output))...);
 }
 
 // Verbose versions of the above:
-template <class T, typename... Values> void print_copy_created(T *inst, Values &&...values) { // NB: this prints, but doesn't store, given values
+template <class T, typename... Values>
+void print_copy_created(T *inst,
+                        Values &&...values) { // NB: this prints, but doesn't store, given values
     print_constr_details(inst, "created via copy constructor", values...);
     track_copy_created(inst);
 }
-template <class T, typename... Values> void print_move_created(T *inst, Values &&...values) { // NB: this prints, but doesn't store, given values
+template <class T, typename... Values>
+void print_move_created(T *inst,
+                        Values &&...values) { // NB: this prints, but doesn't store, given values
     print_constr_details(inst, "created via move constructor", values...);
     track_move_created(inst);
 }
-template <class T, typename... Values> void print_copy_assigned(T *inst, Values &&...values) {
+template <class T, typename... Values>
+void print_copy_assigned(T *inst, Values &&...values) {
     print_constr_details(inst, "assigned via copy assignment", values...);
     track_copy_assigned(inst, values...);
 }
-template <class T, typename... Values> void print_move_assigned(T *inst, Values &&...values) {
+template <class T, typename... Values>
+void print_move_assigned(T *inst, Values &&...values) {
     print_constr_details(inst, "assigned via move assignment", values...);
     track_move_assigned(inst, values...);
 }
-template <class T, typename... Values> void print_default_created(T *inst, Values &&...values) {
+template <class T, typename... Values>
+void print_default_created(T *inst, Values &&...values) {
     print_constr_details(inst, "created via default constructor", values...);
     track_default_created(inst, values...);
 }
-template <class T, typename... Values> void print_created(T *inst, Values &&...values) {
+template <class T, typename... Values>
+void print_created(T *inst, Values &&...values) {
     print_constr_details(inst, "created", values...);
     track_created(inst, values...);
 }
-template <class T, typename... Values> void print_destroyed(T *inst, Values &&...values) { // Prints but doesn't store given values
+template <class T, typename... Values>
+void print_destroyed(T *inst, Values &&...values) { // Prints but doesn't store given values
     print_constr_details(inst, "destroyed", values...);
     track_destroyed(inst);
 }
-template <class T, typename... Values> void print_values(T *inst, Values &&...values) {
+template <class T, typename... Values>
+void print_values(T *inst, Values &&...values) {
     print_constr_details(inst, ":", values...);
     track_values(inst, values...);
 }
diff --git a/tests/cross_module_gil_utils.cpp b/tests/cross_module_gil_utils.cpp
index 07db9f6e48..f3aca1561a 100644
--- a/tests/cross_module_gil_utils.cpp
+++ b/tests/cross_module_gil_utils.cpp
@@ -7,6 +7,7 @@
     BSD-style license that can be found in the LICENSE file.
 */
 #include <pybind11/pybind11.h>
+
 #include <cstdint>
 
 // This file mimics a DSO that makes pybind11 calls but does not define a
@@ -25,34 +26,25 @@ void gil_acquire() { py::gil_scoped_acquire gil; }
 constexpr char kModuleName[] = "cross_module_gil_utils";
 
 #if PY_MAJOR_VERSION >= 3
-struct PyModuleDef moduledef = {
-    PyModuleDef_HEAD_INIT,
-    kModuleName,
-    NULL,
-    0,
-    NULL,
-    NULL,
-    NULL,
-    NULL,
-    NULL
-};
+struct PyModuleDef moduledef
+    = {PyModuleDef_HEAD_INIT, kModuleName, NULL, 0, NULL, NULL, NULL, NULL, NULL};
 #else
-PyMethodDef module_methods[] = {
-    {NULL, NULL, 0, NULL}
-};
+PyMethodDef module_methods[] = {{NULL, NULL, 0, NULL}};
 #endif
 
-}  // namespace
+} // namespace
 
 extern "C" PYBIND11_EXPORT
 #if PY_MAJOR_VERSION >= 3
-PyObject* PyInit_cross_module_gil_utils()
+    PyObject *
+    PyInit_cross_module_gil_utils()
 #else
-void initcross_module_gil_utils()
+    void
+    initcross_module_gil_utils()
 #endif
 {
 
-    PyObject* m =
+    PyObject *m =
 #if PY_MAJOR_VERSION >= 3
         PyModule_Create(&moduledef);
 #else
@@ -60,11 +52,10 @@ void initcross_module_gil_utils()
 #endif
 
     if (m != NULL) {
-        static_assert(
-            sizeof(&gil_acquire) == sizeof(void*),
-            "Function pointer must have the same size as void*");
-        PyModule_AddObject(m, "gil_acquire_funcaddr",
-                           PyLong_FromVoidPtr(reinterpret_cast<void*>(&gil_acquire)));
+        static_assert(sizeof(&gil_acquire) == sizeof(void *),
+                      "Function pointer must have the same size as void*");
+        PyModule_AddObject(
+            m, "gil_acquire_funcaddr", PyLong_FromVoidPtr(reinterpret_cast<void *>(&gil_acquire)));
     }
 
 #if PY_MAJOR_VERSION >= 3
diff --git a/tests/local_bindings.h b/tests/local_bindings.h
index 4c936c19a5..01d2785353 100644
--- a/tests/local_bindings.h
+++ b/tests/local_bindings.h
@@ -1,12 +1,13 @@
 #pragma once
-#include <utility>
-
 #include "pybind11_tests.h"
 
+#include <utility>
+
 /// Simple class used to test py::local:
-template <int> class LocalBase {
+template <int>
+class LocalBase {
 public:
-    explicit LocalBase(int i) : i(i) { }
+    explicit LocalBase(int i) : i(i) {}
     int i = -1;
 };
 
@@ -35,12 +36,12 @@ using NonLocalVec2 = std::vector<NonLocal2>;
 using NonLocalMap = std::unordered_map<std::string, NonLocalType>;
 using NonLocalMap2 = std::unordered_map<std::string, uint8_t>;
 
-
 // Exception that will be caught via the module local translator.
 class LocalException : public std::exception {
 public:
-    explicit LocalException(const char * m) : message{m} {}
-    const char * what() const noexcept override {return message.c_str();}
+    explicit LocalException(const char *m) : message{m} {}
+    const char *what() const noexcept override { return message.c_str(); }
+
 private:
     std::string message = "";
 };
@@ -48,8 +49,9 @@ class LocalException : public std::exception {
 // Exception that will be registered with register_local_exception_translator
 class LocalSimpleException : public std::exception {
 public:
-    explicit LocalSimpleException(const char * m) : message{m} {}
-    const char * what() const noexcept override {return message.c_str();}
+    explicit LocalSimpleException(const char *m) : message{m} {}
+    const char *what() const noexcept override { return message.c_str(); }
+
 private:
     std::string message = "";
 };
@@ -58,17 +60,16 @@ PYBIND11_MAKE_OPAQUE(LocalVec);
 PYBIND11_MAKE_OPAQUE(LocalVec2);
 PYBIND11_MAKE_OPAQUE(LocalMap);
 PYBIND11_MAKE_OPAQUE(NonLocalVec);
-//PYBIND11_MAKE_OPAQUE(NonLocalVec2); // same type as LocalVec2
+// PYBIND11_MAKE_OPAQUE(NonLocalVec2); // same type as LocalVec2
 PYBIND11_MAKE_OPAQUE(NonLocalMap);
 PYBIND11_MAKE_OPAQUE(NonLocalMap2);
 
-
 // Simple bindings (used with the above):
 template <typename T, int Adjust = 0, typename... Args>
-py::class_<T> bind_local(Args && ...args) {
-    return py::class_<T>(std::forward<Args>(args)...)
-        .def(py::init<int>())
-        .def("get", [](T &i) { return i.i + Adjust; });
+py::class_<T> bind_local(Args &&...args) {
+    return py::class_<T>(std::forward<Args>(args)...).def(py::init<int>()).def("get", [](T &i) {
+        return i.i + Adjust;
+    });
 };
 
 // Simulate a foreign library base class (to match the example in the docs):
@@ -81,5 +82,11 @@ class Pet {
 };
 } // namespace pets
 
-struct MixGL { int i; explicit MixGL(int i) : i{i} {} };
-struct MixGL2 { int i; explicit MixGL2(int i) : i{i} {} };
+struct MixGL {
+    int i;
+    explicit MixGL(int i) : i{i} {}
+};
+struct MixGL2 {
+    int i;
+    explicit MixGL2(int i) : i{i} {}
+};
diff --git a/tests/object.h b/tests/object.h
index be21bf6316..c670d66acd 100644
--- a/tests/object.h
+++ b/tests/object.h
@@ -1,8 +1,9 @@
 #if !defined(__OBJECT_H)
-#define __OBJECT_H
+#    define __OBJECT_H
 
-#include <atomic>
-#include "constructor_stats.h"
+#    include "constructor_stats.h"
+
+#    include <atomic>
 
 /// Reference counted object base class
 class Object {
@@ -34,13 +35,15 @@ class Object {
     }
 
     virtual std::string toString() const = 0;
+
 protected:
     /** \brief Virtual protected deconstructor.
      * (Will only be called by \ref ref)
      */
     virtual ~Object() { print_destroyed(this); }
+
 private:
-    mutable std::atomic<int> m_refCount { 0 };
+    mutable std::atomic<int> m_refCount{0};
 };
 
 // Tag class used to track constructions of ref objects.  When we track constructors, below, we
@@ -59,17 +62,22 @@ class ref_tag {};
  *
  * \ingroup libcore
  */
-template <typename T> class ref {
+template <typename T>
+class ref {
 public:
     /// Create a nullptr reference
-    ref() : m_ptr(nullptr) { print_default_created(this); track_default_created((ref_tag*) this); }
+    ref() : m_ptr(nullptr) {
+        print_default_created(this);
+        track_default_created((ref_tag *) this);
+    }
 
     /// Construct a reference from a pointer
     explicit ref(T *ptr) : m_ptr(ptr) {
-        if (m_ptr) ((Object *) m_ptr)->incRef();
-
-        print_created(this, "from pointer", m_ptr); track_created((ref_tag*) this, "from pointer");
+        if (m_ptr)
+            ((Object *) m_ptr)->incRef();
 
+        print_created(this, "from pointer", m_ptr);
+        track_created((ref_tag *) this, "from pointer");
     }
 
     /// Copy constructor
@@ -77,14 +85,16 @@ template <typename T> class ref {
         if (m_ptr)
             ((Object *) m_ptr)->incRef();
 
-        print_copy_created(this, "with pointer", m_ptr); track_copy_created((ref_tag*) this);
+        print_copy_created(this, "with pointer", m_ptr);
+        track_copy_created((ref_tag *) this);
     }
 
     /// Move constructor
     ref(ref &&r) noexcept : m_ptr(r.m_ptr) {
         r.m_ptr = nullptr;
 
-        print_move_created(this, "with pointer", m_ptr); track_move_created((ref_tag*) this);
+        print_move_created(this, "with pointer", m_ptr);
+        track_move_created((ref_tag *) this);
     }
 
     /// Destroy this reference
@@ -92,12 +102,14 @@ template <typename T> class ref {
         if (m_ptr)
             ((Object *) m_ptr)->decRef();
 
-        print_destroyed(this); track_destroyed((ref_tag*) this);
+        print_destroyed(this);
+        track_destroyed((ref_tag *) this);
     }
 
     /// Move another reference into the current one
     ref &operator=(ref &&r) noexcept {
-        print_move_assigned(this, "pointer", r.m_ptr); track_move_assigned((ref_tag*) this);
+        print_move_assigned(this, "pointer", r.m_ptr);
+        track_move_assigned((ref_tag *) this);
 
         if (*this == r)
             return *this;
@@ -109,7 +121,7 @@ template <typename T> class ref {
     }
 
     /// Overwrite this reference with another reference
-    ref& operator=(const ref& r) {
+    ref &operator=(const ref &r) {
         if (this == &r) {
             return *this;
         }
@@ -127,8 +139,9 @@ template <typename T> class ref {
     }
 
     /// Overwrite this reference with a pointer to another object
-    ref& operator=(T *ptr) {
-        print_values(this, "assigned pointer"); track_values((ref_tag*) this, "assigned pointer");
+    ref &operator=(T *ptr) {
+        print_values(this, "assigned pointer");
+        track_values((ref_tag *) this, "assigned pointer");
 
         if (m_ptr == ptr)
             return *this;
@@ -147,31 +160,32 @@ template <typename T> class ref {
     bool operator!=(const ref &r) const { return m_ptr != r.m_ptr; }
 
     /// Compare this reference with a pointer
-    bool operator==(const T* ptr) const { return m_ptr == ptr; }
+    bool operator==(const T *ptr) const { return m_ptr == ptr; }
 
     /// Compare this reference with a pointer
-    bool operator!=(const T* ptr) const { return m_ptr != ptr; }
+    bool operator!=(const T *ptr) const { return m_ptr != ptr; }
 
     /// Access the object referenced by this reference
-    T* operator->() { return m_ptr; }
+    T *operator->() { return m_ptr; }
 
     /// Access the object referenced by this reference
-    const T* operator->() const { return m_ptr; }
+    const T *operator->() const { return m_ptr; }
 
     /// Return a C++ reference to the referenced object
-    T& operator*() { return *m_ptr; }
+    T &operator*() { return *m_ptr; }
 
     /// Return a const C++ reference to the referenced object
-    const T& operator*() const { return *m_ptr; }
+    const T &operator*() const { return *m_ptr; }
 
     /// Return a pointer to the referenced object
-    explicit operator T* () { return m_ptr; }
+    explicit operator T *() { return m_ptr; }
 
     /// Return a const pointer to the referenced object
-    T* get_ptr() { return m_ptr; }
+    T *get_ptr() { return m_ptr; }
 
     /// Return a pointer to the referenced object
-    const T* get_ptr() const { return m_ptr; }
+    const T *get_ptr() const { return m_ptr; }
+
 private:
     T *m_ptr;
 };
diff --git a/tests/pybind11_cross_module_tests.cpp b/tests/pybind11_cross_module_tests.cpp
index 5838cb2746..4739366f11 100644
--- a/tests/pybind11_cross_module_tests.cpp
+++ b/tests/pybind11_cross_module_tests.cpp
@@ -7,12 +7,12 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
+#include <pybind11/stl_bind.h>
+
 #include "local_bindings.h"
+#include "pybind11_tests.h"
 #include "test_exceptions.h"
 
-#include <pybind11/stl_bind.h>
-
 #include <numeric>
 #include <utility>
 
@@ -30,37 +30,44 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) {
 
     // test_exceptions.py
     py::register_local_exception<LocalSimpleException>(m, "LocalSimpleException");
-    m.def("raise_runtime_error", []() { PyErr_SetString(PyExc_RuntimeError, "My runtime error"); throw py::error_already_set(); });
-    m.def("raise_value_error", []() { PyErr_SetString(PyExc_ValueError, "My value error"); throw py::error_already_set(); });
+    m.def("raise_runtime_error", []() {
+        PyErr_SetString(PyExc_RuntimeError, "My runtime error");
+        throw py::error_already_set();
+    });
+    m.def("raise_value_error", []() {
+        PyErr_SetString(PyExc_ValueError, "My value error");
+        throw py::error_already_set();
+    });
     m.def("throw_pybind_value_error", []() { throw py::value_error("pybind11 value error"); });
     m.def("throw_pybind_type_error", []() { throw py::type_error("pybind11 type error"); });
     m.def("throw_stop_iteration", []() { throw py::stop_iteration(); });
     m.def("throw_local_error", []() { throw LocalException("just local"); });
     m.def("throw_local_simple_error", []() { throw LocalSimpleException("external mod"); });
     py::register_exception_translator([](std::exception_ptr p) {
-      try {
-          if (p) std::rethrow_exception(p);
-      } catch (const shared_exception &e) {
-          PyErr_SetString(PyExc_KeyError, e.what());
-      }
+        try {
+            if (p)
+                std::rethrow_exception(p);
+        } catch (const shared_exception &e) {
+            PyErr_SetString(PyExc_KeyError, e.what());
+        }
     });
 
     // translate the local exception into a key error but only in this module
     py::register_local_exception_translator([](std::exception_ptr p) {
-      try {
-          if (p) {
-            std::rethrow_exception(p);
-          }
-      } catch (const LocalException &e) {
-        PyErr_SetString(PyExc_KeyError, e.what());
-      }
+        try {
+            if (p) {
+                std::rethrow_exception(p);
+            }
+        } catch (const LocalException &e) {
+            PyErr_SetString(PyExc_KeyError, e.what());
+        }
     });
 
     // test_local_bindings.py
     // Local to both:
-    bind_local<LocalType, 1>(m, "LocalType", py::module_local())
-        .def("get2", [](LocalType &t) { return t.i + 2; })
-        ;
+    bind_local<LocalType, 1>(m, "LocalType", py::module_local()).def("get2", [](LocalType &t) {
+        return t.i + 2;
+    });
 
     // Can only be called with our python type:
     m.def("local_value", [](LocalType &l) { return l.i; });
@@ -68,9 +75,7 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) {
     // test_nonlocal_failure
     // This registration will fail (global registration when LocalFail is already registered
     // globally in the main test module):
-    m.def("register_nonlocal", [m]() {
-        bind_local<NonLocalType, 0>(m, "NonLocalType");
-    });
+    m.def("register_nonlocal", [m]() { bind_local<NonLocalType, 0>(m, "NonLocalType"); });
 
     // test_stl_bind_local
     // stl_bind.h binders defaults to py::module_local if the types are local or converting:
@@ -80,27 +85,21 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) {
     // test_stl_bind_global
     // and global if the type (or one of the types, for the map) is global (so these will fail,
     // assuming pybind11_tests is already loaded):
-    m.def("register_nonlocal_vec", [m]() {
-        py::bind_vector<NonLocalVec>(m, "NonLocalVec");
-    });
-    m.def("register_nonlocal_map", [m]() {
-        py::bind_map<NonLocalMap>(m, "NonLocalMap");
-    });
+    m.def("register_nonlocal_vec", [m]() { py::bind_vector<NonLocalVec>(m, "NonLocalVec"); });
+    m.def("register_nonlocal_map", [m]() { py::bind_map<NonLocalMap>(m, "NonLocalMap"); });
     // The default can, however, be overridden to global using `py::module_local()` or
     // `py::module_local(false)`.
     // Explicitly made local:
     py::bind_vector<NonLocalVec2>(m, "NonLocalVec2", py::module_local());
     // Explicitly made global (and so will fail to bind):
-    m.def("register_nonlocal_map2", [m]() {
-        py::bind_map<NonLocalMap2>(m, "NonLocalMap2", py::module_local(false));
-    });
+    m.def("register_nonlocal_map2",
+          [m]() { py::bind_map<NonLocalMap2>(m, "NonLocalMap2", py::module_local(false)); });
 
     // test_mixed_local_global
     // We try this both with the global type registered first and vice versa (the order shouldn't
     // matter).
-    m.def("register_mixed_global_local", [m]() {
-        bind_local<MixedGlobalLocal, 200>(m, "MixedGlobalLocal", py::module_local());
-    });
+    m.def("register_mixed_global_local",
+          [m]() { bind_local<MixedGlobalLocal, 200>(m, "MixedGlobalLocal", py::module_local()); });
     m.def("register_mixed_local_global", [m]() {
         bind_local<MixedLocalGlobal, 2000>(m, "MixedLocalGlobal", py::module_local(false));
     });
@@ -108,14 +107,14 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) {
     m.def("get_mixed_lg", [](int i) { return MixedLocalGlobal(i); });
 
     // test_internal_locals_differ
-    m.def("local_cpp_types_addr", []() { return (uintptr_t) &py::detail::get_local_internals().registered_types_cpp; });
+    m.def("local_cpp_types_addr",
+          []() { return (uintptr_t) &py::detail::get_local_internals().registered_types_cpp; });
 
     // test_stl_caster_vs_stl_bind
     py::bind_vector<std::vector<int>>(m, "VectorInt");
 
-    m.def("load_vector_via_binding", [](std::vector<int> &v) {
-        return std::accumulate(v.begin(), v.end(), 0);
-    });
+    m.def("load_vector_via_binding",
+          [](std::vector<int> &v) { return std::accumulate(v.begin(), v.end(), 0); });
 
     // test_cross_module_calls
     m.def("return_self", [](LocalVec *v) { return v; });
@@ -125,11 +124,9 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) {
     public:
         explicit Dog(std::string name) : Pet(std::move(name)) {}
     };
-    py::class_<pets::Pet>(m, "Pet", py::module_local())
-        .def("name", &pets::Pet::name);
+    py::class_<pets::Pet>(m, "Pet", py::module_local()).def("name", &pets::Pet::name);
     // Binding for local extending class:
-    py::class_<Dog, pets::Pet>(m, "Dog")
-        .def(py::init<std::string>());
+    py::class_<Dog, pets::Pet>(m, "Dog").def(py::init<std::string>());
     m.def("pet_name", [](pets::Pet &p) { return p.name(); });
 
     py::class_<MixGL>(m, "MixGL", py::module_local()).def(py::init<int>());
diff --git a/tests/pybind11_tests.cpp b/tests/pybind11_tests.cpp
index 439cd40129..acafeefe44 100644
--- a/tests/pybind11_tests.cpp
+++ b/tests/pybind11_tests.cpp
@@ -8,6 +8,7 @@
 */
 
 #include "pybind11_tests.h"
+
 #include "constructor_stats.h"
 
 #include <functional>
@@ -31,9 +32,7 @@ std::list<std::function<void(py::module_ &)>> &initializers() {
     return inits;
 }
 
-test_initializer::test_initializer(Initializer init) {
-    initializers().emplace_back(init);
-}
+test_initializer::test_initializer(Initializer init) { initializers().emplace_back(init); }
 
 test_initializer::test_initializer(const char *submodule_name, Initializer init) {
     initializers().emplace_back([=](py::module_ &parent) {
@@ -51,15 +50,16 @@ void bind_ConstructorStats(py::module_ &m) {
         .def_readwrite("move_assignments", &ConstructorStats::move_assignments)
         .def_readwrite("copy_constructions", &ConstructorStats::copy_constructions)
         .def_readwrite("move_constructions", &ConstructorStats::move_constructions)
-        .def_static("get", (ConstructorStats &(*)(py::object)) &ConstructorStats::get, py::return_value_policy::reference_internal)
+        .def_static("get",
+                    (ConstructorStats & (*) (py::object)) & ConstructorStats::get,
+                    py::return_value_policy::reference_internal)
 
-        // Not exactly ConstructorStats, but related: expose the internal pybind number of registered instances
-        // to allow instance cleanup checks (invokes a GC first)
+        // Not exactly ConstructorStats, but related: expose the internal pybind number of
+        // registered instances to allow instance cleanup checks (invokes a GC first)
         .def_static("detail_reg_inst", []() {
             ConstructorStats::gc();
             return py::detail::get_internals().registered_instances.size();
-        })
-        ;
+        });
 }
 
 PYBIND11_MODULE(pybind11_tests, m) {
@@ -79,12 +79,12 @@ PYBIND11_MODULE(pybind11_tests, m) {
         .def("get_value", &UserType::value, "Get value using a method")
         .def("set_value", &UserType::set, "Set value using a method")
         .def_property("value", &UserType::value, &UserType::set, "Get/set value using a property")
-        .def("__repr__", [](const UserType& u) { return "UserType({})"_s.format(u.value()); });
+        .def("__repr__", [](const UserType &u) { return "UserType({})"_s.format(u.value()); });
 
     py::class_<IncType, UserType>(m, "IncType")
         .def(py::init<>())
         .def(py::init<int>())
-        .def("__repr__", [](const IncType& u) { return "IncType({})"_s.format(u.value()); });
+        .def("__repr__", [](const IncType &u) { return "IncType({})"_s.format(u.value()); });
 
     for (const auto &initializer : initializers())
         initializer(m);
diff --git a/tests/pybind11_tests.h b/tests/pybind11_tests.h
index 9b99923237..4e9defce33 100644
--- a/tests/pybind11_tests.h
+++ b/tests/pybind11_tests.h
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <pybind11/pybind11.h>
 #include <pybind11/eval.h>
+#include <pybind11/pybind11.h>
 
 #if defined(_MSC_VER) && _MSC_VER < 1910
 // We get some really long type names here which causes MSVC 2015 to emit warnings
@@ -26,13 +26,13 @@ class test_initializer {
     void test_submodule_##name(py::module_ &(variable))
 
 /// Dummy type which is not exported anywhere -- something to trigger a conversion error
-struct UnregisteredType { };
+struct UnregisteredType {};
 
 /// A user-defined type which is exported and can be used by any test
 class UserType {
 public:
     UserType() = default;
-    explicit UserType(int i) : i(i) { }
+    explicit UserType(int i) : i(i) {}
 
     int value() const { return i; }
     void set(int set) { i = set; }
@@ -46,7 +46,7 @@ class IncType : public UserType {
 public:
     using UserType::UserType;
     IncType() = default;
-    IncType(const IncType &other) : IncType(other.value() + 1) { }
+    IncType(const IncType &other) : IncType(other.value() + 1) {}
     IncType(IncType &&) = delete;
     IncType &operator=(const IncType &) = delete;
     IncType &operator=(IncType &&) = delete;
@@ -58,16 +58,21 @@ union IntFloat {
     float f;
 };
 
-/// Custom cast-only type that casts to a string "rvalue" or "lvalue" depending on the cast context.
-/// Used to test recursive casters (e.g. std::tuple, stl containers).
+/// Custom cast-only type that casts to a string "rvalue" or "lvalue" depending on the cast
+/// context. Used to test recursive casters (e.g. std::tuple, stl containers).
 struct RValueCaster {};
 PYBIND11_NAMESPACE_BEGIN(pybind11)
 PYBIND11_NAMESPACE_BEGIN(detail)
-template<> class type_caster<RValueCaster> {
+template <>
+class type_caster<RValueCaster> {
 public:
     PYBIND11_TYPE_CASTER(RValueCaster, const_name("RValueCaster"));
-    static handle cast(RValueCaster &&, return_value_policy, handle) { return py::str("rvalue").release(); }
-    static handle cast(const RValueCaster &, return_value_policy, handle) { return py::str("lvalue").release(); }
+    static handle cast(RValueCaster &&, return_value_policy, handle) {
+        return py::str("rvalue").release();
+    }
+    static handle cast(const RValueCaster &, return_value_policy, handle) {
+        return py::str("lvalue").release();
+    }
 };
 PYBIND11_NAMESPACE_END(detail)
 PYBIND11_NAMESPACE_END(pybind11)
@@ -81,5 +86,6 @@ void ignoreOldStyleInitWarnings(F &&body) {
     with warnings.catch_warnings():
         warnings.filterwarnings("ignore", message=message, category=FutureWarning)
         body()
-    )", py::dict(py::arg("body") = py::cpp_function(body)));
+    )",
+             py::dict(py::arg("body") = py::cpp_function(body)));
 }
diff --git a/tests/test_async.cpp b/tests/test_async.cpp
index e6e01d72c9..a5d7224657 100644
--- a/tests/test_async.cpp
+++ b/tests/test_async.cpp
@@ -11,12 +11,11 @@
 
 TEST_SUBMODULE(async_module, m) {
     struct DoesNotSupportAsync {};
-    py::class_<DoesNotSupportAsync>(m, "DoesNotSupportAsync")
-        .def(py::init<>());
+    py::class_<DoesNotSupportAsync>(m, "DoesNotSupportAsync").def(py::init<>());
     struct SupportsAsync {};
     py::class_<SupportsAsync>(m, "SupportsAsync")
         .def(py::init<>())
-        .def("__await__", [](const SupportsAsync& self) -> py::object {
+        .def("__await__", [](const SupportsAsync &self) -> py::object {
             static_cast<void>(self);
             py::object loop = py::module_::import("asyncio.events").attr("get_event_loop")();
             py::object f = loop.attr("create_future")();
diff --git a/tests/test_buffers.cpp b/tests/test_buffers.cpp
index 3a8e3e7b75..28f144b53f 100644
--- a/tests/test_buffers.cpp
+++ b/tests/test_buffers.cpp
@@ -7,22 +7,24 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
-#include "constructor_stats.h"
 #include <pybind11/stl.h>
 
+#include "constructor_stats.h"
+#include "pybind11_tests.h"
+
 TEST_SUBMODULE(buffers, m) {
     // test_from_python / test_to_python:
     class Matrix {
     public:
         Matrix(py::ssize_t rows, py::ssize_t cols) : m_rows(rows), m_cols(cols) {
             print_created(this, std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
-            m_data = new float[(size_t) (rows*cols)];
+            m_data = new float[(size_t) (rows * cols)];
             memset(m_data, 0, sizeof(float) * (size_t) (rows * cols));
         }
 
         Matrix(const Matrix &s) : m_rows(s.m_rows), m_cols(s.m_cols) {
-            print_copy_created(this, std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
+            print_copy_created(this,
+                               std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
             m_data = new float[(size_t) (m_rows * m_cols)];
             memcpy(m_data, s.m_data, sizeof(float) * (size_t) (m_rows * m_cols));
         }
@@ -35,7 +37,8 @@ TEST_SUBMODULE(buffers, m) {
         }
 
         ~Matrix() {
-            print_destroyed(this, std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
+            print_destroyed(this,
+                            std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
             delete[] m_data;
         }
 
@@ -54,27 +57,33 @@ TEST_SUBMODULE(buffers, m) {
         }
 
         Matrix &operator=(Matrix &&s) noexcept {
-            print_move_assigned(this, std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
+            print_move_assigned(this,
+                                std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
             if (&s != this) {
                 delete[] m_data;
-                m_rows = s.m_rows; m_cols = s.m_cols; m_data = s.m_data;
-                s.m_rows = 0; s.m_cols = 0; s.m_data = nullptr;
+                m_rows = s.m_rows;
+                m_cols = s.m_cols;
+                m_data = s.m_data;
+                s.m_rows = 0;
+                s.m_cols = 0;
+                s.m_data = nullptr;
             }
             return *this;
         }
 
         float operator()(py::ssize_t i, py::ssize_t j) const {
-            return m_data[(size_t) (i*m_cols + j)];
+            return m_data[(size_t) (i * m_cols + j)];
         }
 
         float &operator()(py::ssize_t i, py::ssize_t j) {
-            return m_data[(size_t) (i*m_cols + j)];
+            return m_data[(size_t) (i * m_cols + j)];
         }
 
         float *data() { return m_data; }
 
         py::ssize_t rows() const { return m_rows; }
         py::ssize_t cols() const { return m_cols; }
+
     private:
         py::ssize_t m_rows;
         py::ssize_t m_cols;
@@ -88,7 +97,7 @@ TEST_SUBMODULE(buffers, m) {
             if (info.format != py::format_descriptor<float>::format() || info.ndim != 2)
                 throw std::runtime_error("Incompatible buffer format!");
 
-            auto v = new Matrix(info.shape[0], info.shape[1]);
+            auto *v = new Matrix(info.shape[0], info.shape[1]);
             memcpy(v->data(), info.ptr, sizeof(float) * (size_t) (v->rows() * v->cols()));
             return v;
         }))
@@ -112,11 +121,10 @@ TEST_SUBMODULE(buffers, m) {
         /// Provide buffer access
         .def_buffer([](Matrix &m) -> py::buffer_info {
             return py::buffer_info(
-                m.data(),                               /* Pointer to buffer */
-                { m.rows(), m.cols() },                 /* Buffer dimensions */
-                { sizeof(float) * size_t(m.cols()),     /* Strides (in bytes) for each index */
-                  sizeof(float) }
-            );
+                m.data(),                          /* Pointer to buffer */
+                {m.rows(), m.cols()},              /* Buffer dimensions */
+                {sizeof(float) * size_t(m.cols()), /* Strides (in bytes) for each index */
+                 sizeof(float)});
         });
 
     // test_inherited_protocol
@@ -125,9 +133,7 @@ TEST_SUBMODULE(buffers, m) {
         explicit SquareMatrix(py::ssize_t n) : Matrix(n, n) {}
     };
     // Derived classes inherit the buffer protocol and the buffer access function
-    py::class_<SquareMatrix, Matrix>(m, "SquareMatrix")
-        .def(py::init<py::ssize_t>());
-
+    py::class_<SquareMatrix, Matrix>(m, "SquareMatrix").def(py::init<py::ssize_t>());
 
     // test_pointer_to_member_fn
     // Tests that passing a pointer to member to the base class works in
@@ -136,8 +142,8 @@ TEST_SUBMODULE(buffers, m) {
         int32_t value = 0;
 
         py::buffer_info get_buffer_info() {
-            return py::buffer_info(&value, sizeof(value),
-                                   py::format_descriptor<int32_t>::format(), 1);
+            return py::buffer_info(
+                &value, sizeof(value), py::format_descriptor<int32_t>::format(), 1);
         }
     };
     py::class_<Buffer>(m, "Buffer", py::buffer_protocol())
@@ -145,7 +151,6 @@ TEST_SUBMODULE(buffers, m) {
         .def_readwrite("value", &Buffer::value)
         .def_buffer(&Buffer::get_buffer_info);
 
-
     class ConstBuffer {
         std::unique_ptr<int32_t> value;
 
@@ -154,8 +159,8 @@ TEST_SUBMODULE(buffers, m) {
         void set_value(int32_t v) { *value = v; }
 
         py::buffer_info get_buffer_info() const {
-            return py::buffer_info(value.get(), sizeof(*value),
-                                   py::format_descriptor<int32_t>::format(), 1);
+            return py::buffer_info(
+                value.get(), sizeof(*value), py::format_descriptor<int32_t>::format(), 1);
         }
 
         ConstBuffer() : value(new int32_t{0}) {}
@@ -165,7 +170,7 @@ TEST_SUBMODULE(buffers, m) {
         .def_property("value", &ConstBuffer::get_value, &ConstBuffer::set_value)
         .def_buffer(&ConstBuffer::get_buffer_info);
 
-    struct DerivedBuffer : public Buffer { };
+    struct DerivedBuffer : public Buffer {};
     py::class_<DerivedBuffer>(m, "DerivedBuffer", py::buffer_protocol())
         .def(py::init<>())
         .def_readwrite("value", (int32_t DerivedBuffer::*) &DerivedBuffer::value)
@@ -175,9 +180,7 @@ TEST_SUBMODULE(buffers, m) {
         const uint8_t value = 0;
         explicit BufferReadOnly(uint8_t value) : value(value) {}
 
-        py::buffer_info get_buffer_info() {
-            return py::buffer_info(&value, 1);
-        }
+        py::buffer_info get_buffer_info() { return py::buffer_info(&value, 1); }
     };
     py::class_<BufferReadOnly>(m, "BufferReadOnly", py::buffer_protocol())
         .def(py::init<uint8_t>())
@@ -187,9 +190,7 @@ TEST_SUBMODULE(buffers, m) {
         uint8_t value = 0;
         bool readonly = false;
 
-        py::buffer_info get_buffer_info() {
-            return py::buffer_info(&value, 1, readonly);
-        }
+        py::buffer_info get_buffer_info() { return py::buffer_info(&value, 1, readonly); }
     };
     py::class_<BufferReadOnlySelect>(m, "BufferReadOnlySelect", py::buffer_protocol())
         .def(py::init<>())
@@ -208,9 +209,11 @@ TEST_SUBMODULE(buffers, m) {
         .def_readonly("strides", &py::buffer_info::strides)
         .def_readonly("readonly", &py::buffer_info::readonly)
         .def("__repr__", [](py::handle self) {
-             return py::str("itemsize={0.itemsize!r}, size={0.size!r}, format={0.format!r}, ndim={0.ndim!r}, shape={0.shape!r}, strides={0.strides!r}, readonly={0.readonly!r}").format(self);
-        })
-        ;
+            return py::str("itemsize={0.itemsize!r}, size={0.size!r}, format={0.format!r}, "
+                           "ndim={0.ndim!r}, shape={0.shape!r}, strides={0.strides!r}, "
+                           "readonly={0.readonly!r}")
+                .format(self);
+        });
 
     m.def("get_buffer_info", [](const py::buffer &buffer) { return buffer.request(); });
 }
diff --git a/tests/test_builtin_casters.cpp b/tests/test_builtin_casters.cpp
index 4a9f338378..e2a52c962f 100644
--- a/tests/test_builtin_casters.cpp
+++ b/tests/test_builtin_casters.cpp
@@ -7,64 +7,67 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include <pybind11/complex.h>
 
+#include "pybind11_tests.h"
+
 struct ConstRefCasted {
-  int tag;
+    int tag;
 };
 
 PYBIND11_NAMESPACE_BEGIN(pybind11)
 PYBIND11_NAMESPACE_BEGIN(detail)
 template <>
 class type_caster<ConstRefCasted> {
- public:
-  static constexpr auto name = const_name<ConstRefCasted>();
-
-  // Input is unimportant, a new value will always be constructed based on the
-  // cast operator.
-  bool load(handle, bool) { return true; }
-
-  explicit operator ConstRefCasted &&() {
-      value = {1};
-      // NOLINTNEXTLINE(performance-move-const-arg)
-      return std::move(value);
-  }
-  explicit operator ConstRefCasted &() {
-      value = {2};
-      return value;
-  }
-  explicit operator ConstRefCasted *() {
-      value = {3};
-      return &value;
-  }
-
-  explicit operator const ConstRefCasted &() {
-      value = {4};
-      return value;
-  }
-  explicit operator const ConstRefCasted *() {
-      value = {5};
-      return &value;
-  }
-
-  // custom cast_op to explicitly propagate types to the conversion operators.
-  template <typename T_>
-  using cast_op_type =
-      /// const
-      conditional_t<
-          std::is_same<remove_reference_t<T_>, const ConstRefCasted*>::value, const ConstRefCasted*,
-      conditional_t<
-          std::is_same<T_, const ConstRefCasted&>::value, const ConstRefCasted&,
-      /// non-const
-      conditional_t<
-          std::is_same<remove_reference_t<T_>, ConstRefCasted*>::value, ConstRefCasted*,
-      conditional_t<
-          std::is_same<T_, ConstRefCasted&>::value, ConstRefCasted&,
-          /* else */ConstRefCasted&&>>>>;
-
- private:
-  ConstRefCasted value = {0};
+public:
+    static constexpr auto name = const_name<ConstRefCasted>();
+
+    // Input is unimportant, a new value will always be constructed based on the
+    // cast operator.
+    bool load(handle, bool) { return true; }
+
+    explicit operator ConstRefCasted &&() {
+        value = {1};
+        // NOLINTNEXTLINE(performance-move-const-arg)
+        return std::move(value);
+    }
+    explicit operator ConstRefCasted &() {
+        value = {2};
+        return value;
+    }
+    explicit operator ConstRefCasted *() {
+        value = {3};
+        return &value;
+    }
+
+    explicit operator const ConstRefCasted &() {
+        value = {4};
+        return value;
+    }
+    explicit operator const ConstRefCasted *() {
+        value = {5};
+        return &value;
+    }
+
+    // custom cast_op to explicitly propagate types to the conversion operators.
+    template <typename T_>
+    using cast_op_type =
+        /// const
+        conditional_t<
+            std::is_same<remove_reference_t<T_>, const ConstRefCasted *>::value,
+            const ConstRefCasted *,
+            conditional_t<
+                std::is_same<T_, const ConstRefCasted &>::value,
+                const ConstRefCasted &,
+                /// non-const
+                conditional_t<std::is_same<remove_reference_t<T_>, ConstRefCasted *>::value,
+                              ConstRefCasted *,
+                              conditional_t<std::is_same<T_, ConstRefCasted &>::value,
+                                            ConstRefCasted &,
+                                            /* else */ ConstRefCasted &&>>>>;
+
+private:
+    ConstRefCasted value = {0};
 };
 PYBIND11_NAMESPACE_END(detail)
 PYBIND11_NAMESPACE_END(pybind11)
@@ -74,27 +77,47 @@ TEST_SUBMODULE(builtin_casters, m) {
     m.def("string_roundtrip", [](const char *s) { return s; });
 
     // test_unicode_conversion
-    // Some test characters in utf16 and utf32 encodings.  The last one (the 𝐀) contains a null byte
-    char32_t a32 = 0x61 /*a*/, z32 = 0x7a /*z*/, ib32 = 0x203d /*‽*/, cake32 = 0x1f382 /*🎂*/,              mathbfA32 = 0x1d400 /*𝐀*/;
-    char16_t b16 = 0x62 /*b*/, z16 = 0x7a,       ib16 = 0x203d,       cake16_1 = 0xd83c, cake16_2 = 0xdf82, mathbfA16_1 = 0xd835, mathbfA16_2 = 0xdc00;
+    // Some test characters in utf16 and utf32 encodings.  The last one (the 𝐀) contains a null
+    // byte
+    char32_t a32 = 0x61 /*a*/, z32 = 0x7a /*z*/, ib32 = 0x203d /*‽*/, cake32 = 0x1f382 /*🎂*/,
+             mathbfA32 = 0x1d400 /*𝐀*/;
+    char16_t b16 = 0x62 /*b*/, z16 = 0x7a, ib16 = 0x203d, cake16_1 = 0xd83c, cake16_2 = 0xdf82,
+             mathbfA16_1 = 0xd835, mathbfA16_2 = 0xdc00;
     std::wstring wstr;
-    wstr.push_back(0x61); // a
+    wstr.push_back(0x61);   // a
     wstr.push_back(0x2e18); // ⸘
-    if (PYBIND11_SILENCE_MSVC_C4127(sizeof(wchar_t) == 2)) { wstr.push_back(mathbfA16_1); wstr.push_back(mathbfA16_2); } // 𝐀, utf16
-    else { wstr.push_back((wchar_t) mathbfA32); } // 𝐀, utf32
+    if (PYBIND11_SILENCE_MSVC_C4127(sizeof(wchar_t) == 2)) {
+        wstr.push_back(mathbfA16_1);
+        wstr.push_back(mathbfA16_2);
+    } // 𝐀, utf16
+    else {
+        wstr.push_back((wchar_t) mathbfA32);
+    }                     // 𝐀, utf32
     wstr.push_back(0x7a); // z
 
-    m.def("good_utf8_string", []() { return std::string((const char*)u8"Say utf8\u203d \U0001f382 \U0001d400"); }); // Say utf8‽ 🎂 𝐀
-    m.def("good_utf16_string", [=]() { return std::u16string({ b16, ib16, cake16_1, cake16_2, mathbfA16_1, mathbfA16_2, z16 }); }); // b‽🎂𝐀z
-    m.def("good_utf32_string", [=]() { return std::u32string({ a32, mathbfA32, cake32, ib32, z32 }); }); // a𝐀🎂‽z
+    m.def("good_utf8_string", []() {
+        return std::string((const char *) u8"Say utf8\u203d \U0001f382 \U0001d400");
+    }); // Say utf8‽ 🎂 𝐀
+    m.def("good_utf16_string", [=]() {
+        return std::u16string({b16, ib16, cake16_1, cake16_2, mathbfA16_1, mathbfA16_2, z16});
+    }); // b‽🎂𝐀z
+    m.def("good_utf32_string", [=]() {
+        return std::u32string({a32, mathbfA32, cake32, ib32, z32});
+    });                                                 // a𝐀🎂‽z
     m.def("good_wchar_string", [=]() { return wstr; }); // a‽𝐀z
-    m.def("bad_utf8_string", []()  { return std::string("abc\xd0" "def"); });
-    m.def("bad_utf16_string", [=]() { return std::u16string({ b16, char16_t(0xd800), z16 }); });
+    m.def("bad_utf8_string", []() {
+        return std::string("abc\xd0"
+                           "def");
+    });
+    m.def("bad_utf16_string", [=]() { return std::u16string({b16, char16_t(0xd800), z16}); });
 #if PY_MAJOR_VERSION >= 3
-    // Under Python 2.7, invalid unicode UTF-32 characters don't appear to trigger UnicodeDecodeError
-    m.def("bad_utf32_string", [=]() { return std::u32string({ a32, char32_t(0xd800), z32 }); });
+    // Under Python 2.7, invalid unicode UTF-32 characters don't appear to trigger
+    // UnicodeDecodeError
+    m.def("bad_utf32_string", [=]() { return std::u32string({a32, char32_t(0xd800), z32}); });
     if (PYBIND11_SILENCE_MSVC_C4127(sizeof(wchar_t) == 2))
-        m.def("bad_wchar_string", [=]() { return std::wstring({ wchar_t(0x61), wchar_t(0xd800) }); });
+        m.def("bad_wchar_string", [=]() {
+            return std::wstring({wchar_t(0x61), wchar_t(0xd800)});
+        });
 #endif
     m.def("u8_Z", []() -> char { return 'Z'; });
     m.def("u8_eacute", []() -> char { return '\xe9'; });
@@ -117,8 +140,13 @@ TEST_SUBMODULE(builtin_casters, m) {
 
 #ifdef PYBIND11_HAS_U8STRING
     m.attr("has_u8string") = true;
-    m.def("good_utf8_u8string", []() { return std::u8string(u8"Say utf8\u203d \U0001f382 \U0001d400"); }); // Say utf8‽ 🎂 𝐀
-    m.def("bad_utf8_u8string", []()  { return std::u8string((const char8_t*)"abc\xd0" "def"); });
+    m.def("good_utf8_u8string", []() {
+        return std::u8string(u8"Say utf8\u203d \U0001f382 \U0001d400");
+    }); // Say utf8‽ 🎂 𝐀
+    m.def("bad_utf8_u8string", []() {
+        return std::u8string((const char8_t *) "abc\xd0"
+                                               "def");
+    });
 
     m.def("u8_char8_Z", []() -> char8_t { return u8'Z'; });
 
@@ -130,34 +158,60 @@ TEST_SUBMODULE(builtin_casters, m) {
     // test_string_view
 #ifdef PYBIND11_HAS_STRING_VIEW
     m.attr("has_string_view") = true;
-    m.def("string_view_print",   [](std::string_view s)    { py::print(s, s.size()); });
+    m.def("string_view_print", [](std::string_view s) { py::print(s, s.size()); });
     m.def("string_view16_print", [](std::u16string_view s) { py::print(s, s.size()); });
     m.def("string_view32_print", [](std::u32string_view s) { py::print(s, s.size()); });
-    m.def("string_view_chars",   [](std::string_view s)    { py::list l; for (auto c : s) l.append((std::uint8_t) c); return l; });
-    m.def("string_view16_chars", [](std::u16string_view s) { py::list l; for (auto c : s) l.append((int) c); return l; });
-    m.def("string_view32_chars", [](std::u32string_view s) { py::list l; for (auto c : s) l.append((int) c); return l; });
-    m.def("string_view_return",   []() { return std::string_view((const char*)u8"utf8 secret \U0001f382"); });
-    m.def("string_view16_return", []() { return std::u16string_view(u"utf16 secret \U0001f382"); });
-    m.def("string_view32_return", []() { return std::u32string_view(U"utf32 secret \U0001f382"); });
+    m.def("string_view_chars", [](std::string_view s) {
+        py::list l;
+        for (auto c : s)
+            l.append((std::uint8_t) c);
+        return l;
+    });
+    m.def("string_view16_chars", [](std::u16string_view s) {
+        py::list l;
+        for (auto c : s)
+            l.append((int) c);
+        return l;
+    });
+    m.def("string_view32_chars", [](std::u32string_view s) {
+        py::list l;
+        for (auto c : s)
+            l.append((int) c);
+        return l;
+    });
+    m.def("string_view_return",
+          []() { return std::string_view((const char *) u8"utf8 secret \U0001f382"); });
+    m.def("string_view16_return",
+          []() { return std::u16string_view(u"utf16 secret \U0001f382"); });
+    m.def("string_view32_return",
+          []() { return std::u32string_view(U"utf32 secret \U0001f382"); });
 
     // The inner lambdas here are to also test implicit conversion
     using namespace std::literals;
-    m.def("string_view_bytes", []() { return [](py::bytes b) { return b; }("abc \x80\x80 def"sv); });
-    m.def("string_view_str",   []() { return [](py::str s) { return s; }("abc \342\200\275 def"sv); });
-    m.def("string_view_from_bytes", [](const py::bytes &b) { return [](std::string_view s) { return s; }(b); });
-#if PY_MAJOR_VERSION >= 3
+    m.def("string_view_bytes",
+          []() { return [](py::bytes b) { return b; }("abc \x80\x80 def"sv); });
+    m.def("string_view_str",
+          []() { return [](py::str s) { return s; }("abc \342\200\275 def"sv); });
+    m.def("string_view_from_bytes",
+          [](const py::bytes &b) { return [](std::string_view s) { return s; }(b); });
+#    if PY_MAJOR_VERSION >= 3
     m.def("string_view_memoryview", []() {
         static constexpr auto val = "Have some \360\237\216\202"sv;
         return py::memoryview::from_memory(val);
     });
-#endif
+#    endif
 
-#   ifdef PYBIND11_HAS_U8STRING
-    m.def("string_view8_print",  [](std::u8string_view s) { py::print(s, s.size()); });
-    m.def("string_view8_chars",  [](std::u8string_view s) { py::list l; for (auto c : s) l.append((std::uint8_t) c); return l; });
+#    ifdef PYBIND11_HAS_U8STRING
+    m.def("string_view8_print", [](std::u8string_view s) { py::print(s, s.size()); });
+    m.def("string_view8_chars", [](std::u8string_view s) {
+        py::list l;
+        for (auto c : s)
+            l.append((std::uint8_t) c);
+        return l;
+    });
     m.def("string_view8_return", []() { return std::u8string_view(u8"utf8 secret \U0001f382"); });
-    m.def("string_view8_str",    []() { return py::str{std::u8string_view{u8"abc ‽ def"}}; });
-#   endif
+    m.def("string_view8_str", []() { return py::str{std::u8string_view{u8"abc ‽ def"}}; });
+#    endif
 
     struct TypeWithBothOperatorStringAndStringView {
         // NOLINTNEXTLINE(google-explicit-constructor)
@@ -179,7 +233,8 @@ TEST_SUBMODULE(builtin_casters, m) {
 
     // test_int_convert
     m.def("int_passthrough", [](int arg) { return arg; });
-    m.def("int_passthrough_noconvert", [](int arg) { return arg; }, py::arg{}.noconvert());
+    m.def(
+        "int_passthrough_noconvert", [](int arg) { return arg; }, py::arg{}.noconvert());
 
     // test_tuple
     m.def(
@@ -188,19 +243,27 @@ TEST_SUBMODULE(builtin_casters, m) {
             return std::make_pair(input.second, input.first);
         },
         "Return a pair in reversed order");
-    m.def("tuple_passthrough", [](std::tuple<bool, std::string, int> input) {
-        return std::make_tuple(std::get<2>(input), std::get<1>(input), std::get<0>(input));
-    }, "Return a triple in reversed order");
+    m.def(
+        "tuple_passthrough",
+        [](std::tuple<bool, std::string, int> input) {
+            return std::make_tuple(std::get<2>(input), std::get<1>(input), std::get<0>(input));
+        },
+        "Return a triple in reversed order");
     m.def("empty_tuple", []() { return std::tuple<>(); });
     static std::pair<RValueCaster, RValueCaster> lvpair;
     static std::tuple<RValueCaster, RValueCaster, RValueCaster> lvtuple;
-    static std::pair<RValueCaster, std::tuple<RValueCaster, std::pair<RValueCaster, RValueCaster>>> lvnested;
+    static std::pair<RValueCaster, std::tuple<RValueCaster, std::pair<RValueCaster, RValueCaster>>>
+        lvnested;
     m.def("rvalue_pair", []() { return std::make_pair(RValueCaster{}, RValueCaster{}); });
     m.def("lvalue_pair", []() -> const decltype(lvpair) & { return lvpair; });
-    m.def("rvalue_tuple", []() { return std::make_tuple(RValueCaster{}, RValueCaster{}, RValueCaster{}); });
+    m.def("rvalue_tuple",
+          []() { return std::make_tuple(RValueCaster{}, RValueCaster{}, RValueCaster{}); });
     m.def("lvalue_tuple", []() -> const decltype(lvtuple) & { return lvtuple; });
     m.def("rvalue_nested", []() {
-        return std::make_pair(RValueCaster{}, std::make_tuple(RValueCaster{}, std::make_pair(RValueCaster{}, RValueCaster{}))); });
+        return std::make_pair(
+            RValueCaster{},
+            std::make_tuple(RValueCaster{}, std::make_pair(RValueCaster{}, RValueCaster{})));
+    });
     m.def("lvalue_nested", []() -> const decltype(lvnested) & { return lvnested; });
 
     static std::pair<int, std::string> int_string_pair{2, "items"};
@@ -208,11 +271,11 @@ TEST_SUBMODULE(builtin_casters, m) {
 
     // test_builtins_cast_return_none
     m.def("return_none_string", []() -> std::string * { return nullptr; });
-    m.def("return_none_char",   []() -> const char *  { return nullptr; });
-    m.def("return_none_bool",   []() -> bool *        { return nullptr; });
-    m.def("return_none_int",    []() -> int *         { return nullptr; });
-    m.def("return_none_float",  []() -> float *       { return nullptr; });
-    m.def("return_none_pair",   []() -> std::pair<int,int> * { return nullptr; });
+    m.def("return_none_char", []() -> const char * { return nullptr; });
+    m.def("return_none_bool", []() -> bool * { return nullptr; });
+    m.def("return_none_int", []() -> int * { return nullptr; });
+    m.def("return_none_float", []() -> float * { return nullptr; });
+    m.def("return_none_pair", []() -> std::pair<int, int> * { return nullptr; });
 
     // test_none_deferred
     m.def("defer_none_cstring", [](char *) { return false; });
@@ -230,7 +293,8 @@ TEST_SUBMODULE(builtin_casters, m) {
 
     // test_bool_caster
     m.def("bool_passthrough", [](bool arg) { return arg; });
-    m.def("bool_passthrough_noconvert", [](bool arg) { return arg; }, py::arg{}.noconvert());
+    m.def(
+        "bool_passthrough_noconvert", [](bool arg) { return arg; }, py::arg{}.noconvert());
 
     // TODO: This should be disabled and fixed in future Intel compilers
 #if !defined(__INTEL_COMPILER)
@@ -238,13 +302,15 @@ TEST_SUBMODULE(builtin_casters, m) {
     // When compiled with the Intel compiler, this results in segmentation faults when importing
     // the module. Tested with icc (ICC) 2021.1 Beta 20200827, this should be tested again when
     // a newer version of icc is available.
-    m.def("bool_passthrough_noconvert2", [](bool arg) { return arg; }, py::arg().noconvert());
+    m.def(
+        "bool_passthrough_noconvert2", [](bool arg) { return arg; }, py::arg().noconvert());
 #endif
 
     // test_reference_wrapper
     m.def("refwrap_builtin", [](std::reference_wrapper<int> p) { return 10 * p.get(); });
     m.def("refwrap_usertype", [](std::reference_wrapper<UserType> p) { return p.get().value(); });
-    m.def("refwrap_usertype_const", [](std::reference_wrapper<const UserType> p) { return p.get().value(); });
+    m.def("refwrap_usertype_const",
+          [](std::reference_wrapper<const UserType> p) { return p.get().value(); });
 
     m.def("refwrap_lvalue", []() -> std::reference_wrapper<UserType> {
         static UserType x(1);
@@ -257,17 +323,20 @@ TEST_SUBMODULE(builtin_casters, m) {
 
     // Not currently supported (std::pair caster has return-by-value cast operator);
     // triggers static_assert failure.
-    //m.def("refwrap_pair", [](std::reference_wrapper<std::pair<int, int>>) { });
+    // m.def("refwrap_pair", [](std::reference_wrapper<std::pair<int, int>>) { });
 
-    m.def("refwrap_list", [](bool copy) {
-        static IncType x1(1), x2(2);
-        py::list l;
-        for (auto &f : {std::ref(x1), std::ref(x2)}) {
-            l.append(py::cast(f, copy ? py::return_value_policy::copy
-                                      : py::return_value_policy::reference));
-        }
-        return l;
-    }, "copy"_a);
+    m.def(
+        "refwrap_list",
+        [](bool copy) {
+            static IncType x1(1), x2(2);
+            py::list l;
+            for (const auto &f : {std::ref(x1), std::ref(x2)}) {
+                l.append(py::cast(
+                    f, copy ? py::return_value_policy::copy : py::return_value_policy::reference));
+            }
+            return l;
+        },
+        "copy"_a);
 
     m.def("refwrap_iiw", [](const IncType &w) { return w.value(); });
     m.def("refwrap_call_iiw", [](IncType &w, const py::function &f) {
@@ -284,12 +353,13 @@ TEST_SUBMODULE(builtin_casters, m) {
 
     // test_complex
     m.def("complex_cast", [](float x) { return "{}"_s.format(x); });
-    m.def("complex_cast", [](std::complex<float> x) { return "({}, {})"_s.format(x.real(), x.imag()); });
+    m.def("complex_cast",
+          [](std::complex<float> x) { return "({}, {})"_s.format(x.real(), x.imag()); });
 
     // test int vs. long (Python 2)
-    m.def("int_cast", []() {return (int) 42;});
-    m.def("long_cast", []() {return (long) 42;});
-    m.def("longlong_cast", []() {return  ULLONG_MAX;});
+    m.def("int_cast", []() { return (int) 42; });
+    m.def("long_cast", []() { return (long) 42; });
+    m.def("longlong_cast", []() { return ULLONG_MAX; });
 
     /// test void* cast operator
     m.def("test_void_caster", []() -> bool {
@@ -300,11 +370,12 @@ TEST_SUBMODULE(builtin_casters, m) {
 
     // Tests const/non-const propagation in cast_op.
     m.def("takes", [](ConstRefCasted x) { return x.tag; });
-    m.def("takes_move", [](ConstRefCasted&& x) { return x.tag; });
-    m.def("takes_ptr", [](ConstRefCasted* x) { return x->tag; });
-    m.def("takes_ref", [](ConstRefCasted& x) { return x.tag; });
+    m.def("takes_move", [](ConstRefCasted &&x) { return x.tag; });
+    m.def("takes_ptr", [](ConstRefCasted *x) { return x->tag; });
+    m.def("takes_ref", [](ConstRefCasted &x) { return x.tag; });
     m.def("takes_ref_wrap", [](std::reference_wrapper<ConstRefCasted> x) { return x.get().tag; });
-    m.def("takes_const_ptr", [](const ConstRefCasted* x) { return x->tag; });
-    m.def("takes_const_ref", [](const ConstRefCasted& x) { return x.tag; });
-    m.def("takes_const_ref_wrap", [](std::reference_wrapper<const ConstRefCasted> x) { return x.get().tag; });
+    m.def("takes_const_ptr", [](const ConstRefCasted *x) { return x->tag; });
+    m.def("takes_const_ref", [](const ConstRefCasted &x) { return x.tag; });
+    m.def("takes_const_ref_wrap",
+          [](std::reference_wrapper<const ConstRefCasted> x) { return x.get().tag; });
 }
diff --git a/tests/test_call_policies.cpp b/tests/test_call_policies.cpp
index 7cb98d0d86..d25ef52b86 100644
--- a/tests/test_call_policies.cpp
+++ b/tests/test_call_policies.cpp
@@ -40,18 +40,17 @@ TEST_SUBMODULE(call_policies, m) {
         Child(Child &&) = default;
         ~Child() { py::print("Releasing child."); }
     };
-    py::class_<Child>(m, "Child")
-        .def(py::init<>());
+    py::class_<Child>(m, "Child").def(py::init<>());
 
     class Parent {
     public:
         Parent() { py::print("Allocating parent."); }
-        Parent(const Parent& parent) = default;
+        Parent(const Parent &parent) = default;
         ~Parent() { py::print("Releasing parent."); }
-        void addChild(Child *) { }
+        void addChild(Child *) {}
         Child *returnChild() { return new Child(); }
         Child *returnNullChild() { return nullptr; }
-        static Child *staticFunction(Parent*) { return new Child(); }
+        static Child *staticFunction(Parent *) { return new Child(); }
     };
     py::class_<Parent>(m, "Parent")
         .def(py::init<>())
@@ -62,11 +61,12 @@ TEST_SUBMODULE(call_policies, m) {
         .def("returnChildKeepAlive", &Parent::returnChild, py::keep_alive<1, 0>())
         .def("returnNullChildKeepAliveChild", &Parent::returnNullChild, py::keep_alive<1, 0>())
         .def("returnNullChildKeepAliveParent", &Parent::returnNullChild, py::keep_alive<0, 1>())
-        .def_static(
-            "staticFunction", &Parent::staticFunction, py::keep_alive<1, 0>());
+        .def_static("staticFunction", &Parent::staticFunction, py::keep_alive<1, 0>());
 
-    m.def("free_function", [](Parent*, Child*) {}, py::keep_alive<1, 2>());
-    m.def("invalid_arg_index", []{}, py::keep_alive<0, 1>());
+    m.def(
+        "free_function", [](Parent *, Child *) {}, py::keep_alive<1, 2>());
+    m.def(
+        "invalid_arg_index", [] {}, py::keep_alive<0, 1>());
 
 #if !defined(PYPY_VERSION)
     // test_alive_gc
@@ -74,28 +74,35 @@ TEST_SUBMODULE(call_policies, m) {
     public:
         using Parent::Parent;
     };
-    py::class_<ParentGC, Parent>(m, "ParentGC", py::dynamic_attr())
-        .def(py::init<>());
+    py::class_<ParentGC, Parent>(m, "ParentGC", py::dynamic_attr()).def(py::init<>());
 #endif
 
     // test_call_guard
     m.def("unguarded_call", &CustomGuard::report_status);
     m.def("guarded_call", &CustomGuard::report_status, py::call_guard<CustomGuard>());
 
-    m.def("multiple_guards_correct_order", []() {
-        return CustomGuard::report_status() + std::string(" & ") + DependentGuard::report_status();
-    }, py::call_guard<CustomGuard, DependentGuard>());
-
-    m.def("multiple_guards_wrong_order", []() {
-        return DependentGuard::report_status() + std::string(" & ") + CustomGuard::report_status();
-    }, py::call_guard<DependentGuard, CustomGuard>());
+    m.def(
+        "multiple_guards_correct_order",
+        []() {
+            return CustomGuard::report_status() + std::string(" & ")
+                   + DependentGuard::report_status();
+        },
+        py::call_guard<CustomGuard, DependentGuard>());
+
+    m.def(
+        "multiple_guards_wrong_order",
+        []() {
+            return DependentGuard::report_status() + std::string(" & ")
+                   + CustomGuard::report_status();
+        },
+        py::call_guard<DependentGuard, CustomGuard>());
 
 #if defined(WITH_THREAD) && !defined(PYPY_VERSION)
     // `py::call_guard<py::gil_scoped_release>()` should work in PyPy as well,
     // but it's unclear how to test it without `PyGILState_GetThisThreadState`.
     auto report_gil_status = []() {
         auto is_gil_held = false;
-        if (auto tstate = py::detail::get_thread_state_unchecked())
+        if (auto *tstate = py::detail::get_thread_state_unchecked())
             is_gil_held = (tstate == PyGILState_GetThisThreadState());
 
         return is_gil_held ? "GIL held" : "GIL released";
diff --git a/tests/test_callbacks.cpp b/tests/test_callbacks.cpp
index 58688b6e8b..0d2eccc2bf 100644
--- a/tests/test_callbacks.cpp
+++ b/tests/test_callbacks.cpp
@@ -7,11 +7,12 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
-#include "constructor_stats.h"
 #include <pybind11/functional.h>
-#include <thread>
 
+#include "constructor_stats.h"
+#include "pybind11_tests.h"
+
+#include <thread>
 
 int dummy_function(int i) { return i + 1; }
 
@@ -20,11 +21,12 @@ TEST_SUBMODULE(callbacks, m) {
     m.def("test_callback1", [](const py::object &func) { return func(); });
     m.def("test_callback2", [](const py::object &func) { return func("Hello", 'x', true, 5); });
     m.def("test_callback3", [](const std::function<int(int)> &func) {
-        return "func(43) = " + std::to_string(func(43)); });
-    m.def("test_callback4", []() -> std::function<int(int)> { return [](int i) { return i+1; }; });
-    m.def("test_callback5", []() {
-        return py::cpp_function([](int i) { return i+1; }, py::arg("number"));
+        return "func(43) = " + std::to_string(func(43));
     });
+    m.def("test_callback4",
+          []() -> std::function<int(int)> { return [](int i) { return i + 1; }; });
+    m.def("test_callback5",
+          []() { return py::cpp_function([](int i) { return i + 1; }, py::arg("number")); });
 
     // test_keyword_args_and_generalized_unpacking
     m.def("test_tuple_unpacking", [](const py::function &f) {
@@ -34,9 +36,9 @@ TEST_SUBMODULE(callbacks, m) {
     });
 
     m.def("test_dict_unpacking", [](const py::function &f) {
-        auto d1 = py::dict("key"_a="value", "a"_a=1);
+        auto d1 = py::dict("key"_a = "value", "a"_a = 1);
         auto d2 = py::dict();
-        auto d3 = py::dict("b"_a=2);
+        auto d3 = py::dict("b"_a = 2);
         return f("positional", 1, **d1, **d2, **d3);
     });
 
@@ -44,32 +46,40 @@ TEST_SUBMODULE(callbacks, m) {
 
     m.def("test_unpacking_and_keywords1", [](const py::function &f) {
         auto args = py::make_tuple(2);
-        auto kwargs = py::dict("d"_a=4);
-        return f(1, *args, "c"_a=3, **kwargs);
+        auto kwargs = py::dict("d"_a = 4);
+        return f(1, *args, "c"_a = 3, **kwargs);
     });
 
     m.def("test_unpacking_and_keywords2", [](const py::function &f) {
-        auto kwargs1 = py::dict("a"_a=1);
-        auto kwargs2 = py::dict("c"_a=3, "d"_a=4);
-        return f("positional", *py::make_tuple(1), 2, *py::make_tuple(3, 4), 5,
-                 "key"_a="value", **kwargs1, "b"_a=2, **kwargs2, "e"_a=5);
+        auto kwargs1 = py::dict("a"_a = 1);
+        auto kwargs2 = py::dict("c"_a = 3, "d"_a = 4);
+        return f("positional",
+                 *py::make_tuple(1),
+                 2,
+                 *py::make_tuple(3, 4),
+                 5,
+                 "key"_a = "value",
+                 **kwargs1,
+                 "b"_a = 2,
+                 **kwargs2,
+                 "e"_a = 5);
     });
 
     m.def("test_unpacking_error1", [](const py::function &f) {
-        auto kwargs = py::dict("x"_a=3);
-        return f("x"_a=1, "y"_a=2, **kwargs); // duplicate ** after keyword
+        auto kwargs = py::dict("x"_a = 3);
+        return f("x"_a = 1, "y"_a = 2, **kwargs); // duplicate ** after keyword
     });
 
     m.def("test_unpacking_error2", [](const py::function &f) {
-        auto kwargs = py::dict("x"_a=3);
-        return f(**kwargs, "x"_a=1); // duplicate keyword after **
+        auto kwargs = py::dict("x"_a = 3);
+        return f(**kwargs, "x"_a = 1); // duplicate keyword after **
     });
 
     m.def("test_arg_conversion_error1",
           [](const py::function &f) { f(234, UnregisteredType(), "kw"_a = 567); });
 
     m.def("test_arg_conversion_error2", [](const py::function &f) {
-        f(234, "expected_name"_a=UnregisteredType(), "kw"_a=567);
+        f(234, "expected_name"_a = UnregisteredType(), "kw"_a = 567);
     });
 
     // test_lambda_closure_cleanup
@@ -136,14 +146,18 @@ TEST_SUBMODULE(callbacks, m) {
     m.def("dummy_function_overloaded", [](int i, int j) { return i + j; });
     m.def("dummy_function_overloaded", &dummy_function);
     m.def("dummy_function2", [](int i, int j) { return i + j; });
-    m.def("roundtrip", [](std::function<int(int)> f, bool expect_none = false) {
-        if (expect_none && f)
-            throw std::runtime_error("Expected None to be converted to empty std::function");
-        return f;
-    }, py::arg("f"), py::arg("expect_none")=false);
+    m.def(
+        "roundtrip",
+        [](std::function<int(int)> f, bool expect_none = false) {
+            if (expect_none && f)
+                throw std::runtime_error("Expected None to be converted to empty std::function");
+            return f;
+        },
+        py::arg("f"),
+        py::arg("expect_none") = false);
     m.def("test_dummy_function", [](const std::function<int(int)> &f) -> std::string {
         using fn_type = int (*)(int);
-        auto result = f.target<fn_type>();
+        const auto *result = f.target<fn_type>();
         if (!result) {
             auto r = f(1);
             return "can't convert to function pointer: eval(1) = " + std::to_string(r);
@@ -153,7 +167,6 @@ TEST_SUBMODULE(callbacks, m) {
             return "matches dummy_function: eval(1) = " + std::to_string(r);
         }
         return "argument does NOT match dummy_function. This should never happen!";
-
     });
 
     class AbstractBase {
@@ -185,7 +198,7 @@ TEST_SUBMODULE(callbacks, m) {
     // test_movable_object
     m.def("callback_with_movable", [](const std::function<void(MovableObject &)> &f) {
         auto x = MovableObject();
-        f(x); // lvalue reference shouldn't move out object
+        f(x);           // lvalue reference shouldn't move out object
         return x.valid; // must still return `true`
     });
 
@@ -197,9 +210,10 @@ TEST_SUBMODULE(callbacks, m) {
 
     // This checks that builtin functions can be passed as callbacks
     // rather than throwing RuntimeError due to trying to extract as capsule
-    m.def("test_sum_builtin", [](const std::function<double(py::iterable)> &sum_builtin, const py::iterable &i) {
-      return sum_builtin(i);
-    });
+    m.def("test_sum_builtin",
+          [](const std::function<double(py::iterable)> &sum_builtin, const py::iterable &i) {
+              return sum_builtin(i);
+          });
 
     // test async Python callbacks
     using callback_f = std::function<void(int)>;
diff --git a/tests/test_chrono.cpp b/tests/test_chrono.cpp
index 6537050803..8be0ffd183 100644
--- a/tests/test_chrono.cpp
+++ b/tests/test_chrono.cpp
@@ -8,21 +8,20 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include <pybind11/chrono.h>
+
+#include "pybind11_tests.h"
+
 #include <chrono>
 
 struct different_resolutions {
-    using time_point_h = std::chrono::time_point<
-        std::chrono::system_clock, std::chrono::hours>;
-    using time_point_m = std::chrono::time_point<
-        std::chrono::system_clock, std::chrono::minutes>;
-    using time_point_s = std::chrono::time_point<
-        std::chrono::system_clock, std::chrono::seconds>;
-    using time_point_ms = std::chrono::time_point<
-        std::chrono::system_clock, std::chrono::milliseconds>;
-    using time_point_us = std::chrono::time_point<
-        std::chrono::system_clock, std::chrono::microseconds>;
+    using time_point_h = std::chrono::time_point<std::chrono::system_clock, std::chrono::hours>;
+    using time_point_m = std::chrono::time_point<std::chrono::system_clock, std::chrono::minutes>;
+    using time_point_s = std::chrono::time_point<std::chrono::system_clock, std::chrono::seconds>;
+    using time_point_ms
+        = std::chrono::time_point<std::chrono::system_clock, std::chrono::milliseconds>;
+    using time_point_us
+        = std::chrono::time_point<std::chrono::system_clock, std::chrono::microseconds>;
     time_point_h timestamp_h;
     time_point_m timestamp_m;
     time_point_s timestamp_s;
@@ -65,12 +64,11 @@ TEST_SUBMODULE(chrono, m) {
     // Roundtrip a duration in microseconds from a float argument
     m.def("test_chrono7", [](std::chrono::microseconds t) { return t; });
     // Float durations (issue #719)
-    m.def("test_chrono_float_diff", [](std::chrono::duration<float> a, std::chrono::duration<float> b) {
-        return a - b; });
+    m.def("test_chrono_float_diff",
+          [](std::chrono::duration<float> a, std::chrono::duration<float> b) { return a - b; });
 
-    m.def("test_nano_timepoint", [](timestamp start, timespan delta) -> timestamp {
-        return start + delta;
-    });
+    m.def("test_nano_timepoint",
+          [](timestamp start, timespan delta) -> timestamp { return start + delta; });
 
     // Test different resolutions
     py::class_<different_resolutions>(m, "different_resolutions")
@@ -79,6 +77,5 @@ TEST_SUBMODULE(chrono, m) {
         .def_readwrite("timestamp_m", &different_resolutions::timestamp_m)
         .def_readwrite("timestamp_s", &different_resolutions::timestamp_s)
         .def_readwrite("timestamp_ms", &different_resolutions::timestamp_ms)
-        .def_readwrite("timestamp_us", &different_resolutions::timestamp_us)
-        ;
+        .def_readwrite("timestamp_us", &different_resolutions::timestamp_us);
 }
diff --git a/tests/test_class.cpp b/tests/test_class.cpp
index 52a41a3bc0..cab37f4c0b 100644
--- a/tests/test_class.cpp
+++ b/tests/test_class.cpp
@@ -11,18 +11,20 @@
 // Intel compiler requires a separate header file to support aligned new operators
 // and does not set the __cpp_aligned_new feature macro.
 // This header needs to be included before pybind11.
-#include <aligned_new>
+#    include <aligned_new>
 #endif
 
-#include "pybind11_tests.h"
+#include <pybind11/stl.h>
+
 #include "constructor_stats.h"
 #include "local_bindings.h"
-#include <pybind11/stl.h>
+#include "pybind11_tests.h"
 
 #include <utility>
 
 #if defined(_MSC_VER)
-#  pragma warning(disable: 4324) // warning C4324: structure was padded due to alignment specifier
+#    pragma warning(                                                                              \
+        disable : 4324) // warning C4324: structure was padded due to alignment specifier
 #endif
 
 // test_brace_initialization
@@ -74,6 +76,7 @@ TEST_SUBMODULE(class_, m) {
             : m_name(name), m_species(species) {}
         std::string name() const { return m_name; }
         std::string species() const { return m_species; }
+
     private:
         std::string m_name;
         std::string m_species;
@@ -100,27 +103,24 @@ TEST_SUBMODULE(class_, m) {
     };
 
     py::class_<Pet> pet_class(m, "Pet");
-    pet_class
-        .def(py::init<std::string, std::string>())
+    pet_class.def(py::init<std::string, std::string>())
         .def("name", &Pet::name)
         .def("species", &Pet::species);
 
     /* One way of declaring a subclass relationship: reference parent's class_ object */
-    py::class_<Dog>(m, "Dog", pet_class)
-        .def(py::init<std::string>());
+    py::class_<Dog>(m, "Dog", pet_class).def(py::init<std::string>());
 
     /* Another way of declaring a subclass relationship: reference parent's C++ type */
-    py::class_<Rabbit, Pet>(m, "Rabbit")
-        .def(py::init<std::string>());
+    py::class_<Rabbit, Pet>(m, "Rabbit").def(py::init<std::string>());
 
     /* And another: list parent in class template arguments */
-    py::class_<Hamster, Pet>(m, "Hamster")
-        .def(py::init<std::string>());
+    py::class_<Hamster, Pet>(m, "Hamster").def(py::init<std::string>());
 
     /* Constructors are not inherited by default */
     py::class_<Chimera, Pet>(m, "Chimera");
 
-    m.def("pet_name_species", [](const Pet &pet) { return pet.name() + " is a " + pet.species(); });
+    m.def("pet_name_species",
+          [](const Pet &pet) { return pet.name() + " is a " + pet.species(); });
     m.def("dog_bark", [](const Dog &dog) { return dog.bark(); });
 
     // test_automatic_upcasting
@@ -130,33 +130,33 @@ TEST_SUBMODULE(class_, m) {
         BaseClass(BaseClass &&) = default;
         virtual ~BaseClass() = default;
     };
-    struct DerivedClass1 : BaseClass { };
-    struct DerivedClass2 : BaseClass { };
+    struct DerivedClass1 : BaseClass {};
+    struct DerivedClass2 : BaseClass {};
 
     py::class_<BaseClass>(m, "BaseClass").def(py::init<>());
     py::class_<DerivedClass1>(m, "DerivedClass1").def(py::init<>());
     py::class_<DerivedClass2>(m, "DerivedClass2").def(py::init<>());
 
-    m.def("return_class_1", []() -> BaseClass* { return new DerivedClass1(); });
-    m.def("return_class_2", []() -> BaseClass* { return new DerivedClass2(); });
-    m.def("return_class_n", [](int n) -> BaseClass* {
-        if (n == 1) return new DerivedClass1();
-        if (n == 2) return new DerivedClass2();
+    m.def("return_class_1", []() -> BaseClass * { return new DerivedClass1(); });
+    m.def("return_class_2", []() -> BaseClass * { return new DerivedClass2(); });
+    m.def("return_class_n", [](int n) -> BaseClass * {
+        if (n == 1)
+            return new DerivedClass1();
+        if (n == 2)
+            return new DerivedClass2();
         return new BaseClass();
     });
-    m.def("return_none", []() -> BaseClass* { return nullptr; });
+    m.def("return_none", []() -> BaseClass * { return nullptr; });
 
     // test_isinstance
     m.def("check_instances", [](const py::list &l) {
-        return py::make_tuple(
-            py::isinstance<py::tuple>(l[0]),
-            py::isinstance<py::dict>(l[1]),
-            py::isinstance<Pet>(l[2]),
-            py::isinstance<Pet>(l[3]),
-            py::isinstance<Dog>(l[4]),
-            py::isinstance<Rabbit>(l[5]),
-            py::isinstance<UnregisteredType>(l[6])
-        );
+        return py::make_tuple(py::isinstance<py::tuple>(l[0]),
+                              py::isinstance<py::dict>(l[1]),
+                              py::isinstance<Pet>(l[2]),
+                              py::isinstance<Pet>(l[3]),
+                              py::isinstance<Dog>(l[4]),
+                              py::isinstance<Rabbit>(l[5]),
+                              py::isinstance<UnregisteredType>(l[6]));
     });
 
     struct Invalid {};
@@ -174,18 +174,16 @@ TEST_SUBMODULE(class_, m) {
 
     m.def("get_type_of", [](py::object ob) { return py::type::of(std::move(ob)); });
 
-    m.def("get_type_classic", [](py::handle h) {
-        return h.get_type();
-    });
+    m.def("get_type_classic", [](py::handle h) { return h.get_type(); });
 
     m.def("as_type", [](const py::object &ob) { return py::type(ob); });
 
     // test_mismatched_holder
-    struct MismatchBase1 { };
-    struct MismatchDerived1 : MismatchBase1 { };
+    struct MismatchBase1 {};
+    struct MismatchDerived1 : MismatchBase1 {};
 
-    struct MismatchBase2 { };
-    struct MismatchDerived2 : MismatchBase2 { };
+    struct MismatchBase2 {};
+    struct MismatchDerived2 : MismatchBase2 {};
 
     m.def("mismatched_holder_1", []() {
         auto mod = py::module_::import("__main__");
@@ -195,16 +193,14 @@ TEST_SUBMODULE(class_, m) {
     m.def("mismatched_holder_2", []() {
         auto mod = py::module_::import("__main__");
         py::class_<MismatchBase2>(mod, "MismatchBase2");
-        py::class_<MismatchDerived2, std::shared_ptr<MismatchDerived2>,
-                   MismatchBase2>(mod, "MismatchDerived2");
+        py::class_<MismatchDerived2, std::shared_ptr<MismatchDerived2>, MismatchBase2>(
+            mod, "MismatchDerived2");
     });
 
     // test_override_static
     // #511: problem with inheritance + overwritten def_static
     struct MyBase {
-        static std::unique_ptr<MyBase> make() {
-            return std::unique_ptr<MyBase>(new MyBase());
-        }
+        static std::unique_ptr<MyBase> make() { return std::unique_ptr<MyBase>(new MyBase()); }
     };
 
     struct MyDerived : MyBase {
@@ -213,8 +209,7 @@ TEST_SUBMODULE(class_, m) {
         }
     };
 
-    py::class_<MyBase>(m, "MyBase")
-        .def_static("make", &MyBase::make);
+    py::class_<MyBase>(m, "MyBase").def_static("make", &MyBase::make);
 
     py::class_<MyDerived, MyBase>(m, "MyDerived")
         .def_static("make", &MyDerived::make)
@@ -227,8 +222,7 @@ TEST_SUBMODULE(class_, m) {
         explicit ConvertibleFromUserType(UserType u) : i(u.value()) {}
     };
 
-    py::class_<ConvertibleFromUserType>(m, "AcceptsUserType")
-        .def(py::init<UserType>());
+    py::class_<ConvertibleFromUserType>(m, "AcceptsUserType").def(py::init<UserType>());
     py::implicitly_convertible<UserType, ConvertibleFromUserType>();
 
     m.def("implicitly_convert_argument", [](const ConvertibleFromUserType &r) { return r.i; });
@@ -250,32 +244,61 @@ TEST_SUBMODULE(class_, m) {
             return py::str().release().ptr();
         };
 
-        auto def = new PyMethodDef{"f", f, METH_VARARGS, nullptr};
-        py::capsule def_capsule(def, [](void *ptr) { delete reinterpret_cast<PyMethodDef *>(ptr); });
-        return py::reinterpret_steal<py::object>(PyCFunction_NewEx(def, def_capsule.ptr(), m.ptr()));
+        auto *def = new PyMethodDef{"f", f, METH_VARARGS, nullptr};
+        py::capsule def_capsule(def,
+                                [](void *ptr) { delete reinterpret_cast<PyMethodDef *>(ptr); });
+        return py::reinterpret_steal<py::object>(
+            PyCFunction_NewEx(def, def_capsule.ptr(), m.ptr()));
     }());
 
     // test_operator_new_delete
     struct HasOpNewDel {
         std::uint64_t i;
-        static void *operator new(size_t s) { py::print("A new", s); return ::operator new(s); }
-        static void *operator new(size_t s, void *ptr) { py::print("A placement-new", s); return ptr; }
-        static void operator delete(void *p) { py::print("A delete"); return ::operator delete(p); }
+        static void *operator new(size_t s) {
+            py::print("A new", s);
+            return ::operator new(s);
+        }
+        static void *operator new(size_t s, void *ptr) {
+            py::print("A placement-new", s);
+            return ptr;
+        }
+        static void operator delete(void *p) {
+            py::print("A delete");
+            return ::operator delete(p);
+        }
     };
     struct HasOpNewDelSize {
         std::uint32_t i;
-        static void *operator new(size_t s) { py::print("B new", s); return ::operator new(s); }
-        static void *operator new(size_t s, void *ptr) { py::print("B placement-new", s); return ptr; }
-        static void operator delete(void *p, size_t s) { py::print("B delete", s); return ::operator delete(p); }
+        static void *operator new(size_t s) {
+            py::print("B new", s);
+            return ::operator new(s);
+        }
+        static void *operator new(size_t s, void *ptr) {
+            py::print("B placement-new", s);
+            return ptr;
+        }
+        static void operator delete(void *p, size_t s) {
+            py::print("B delete", s);
+            return ::operator delete(p);
+        }
     };
     struct AliasedHasOpNewDelSize {
         std::uint64_t i;
-        static void *operator new(size_t s) { py::print("C new", s); return ::operator new(s); }
-        static void *operator new(size_t s, void *ptr) { py::print("C placement-new", s); return ptr; }
-        static void operator delete(void *p, size_t s) { py::print("C delete", s); return ::operator delete(p); }
+        static void *operator new(size_t s) {
+            py::print("C new", s);
+            return ::operator new(s);
+        }
+        static void *operator new(size_t s, void *ptr) {
+            py::print("C placement-new", s);
+            return ptr;
+        }
+        static void operator delete(void *p, size_t s) {
+            py::print("C delete", s);
+            return ::operator delete(p);
+        }
         virtual ~AliasedHasOpNewDelSize() = default;
         AliasedHasOpNewDelSize() = default;
-        AliasedHasOpNewDelSize(const AliasedHasOpNewDelSize&) = delete;
+        AliasedHasOpNewDelSize(const AliasedHasOpNewDelSize &) = delete;
     };
     struct PyAliasedHasOpNewDelSize : AliasedHasOpNewDelSize {
         PyAliasedHasOpNewDelSize() = default;
@@ -284,15 +307,28 @@ TEST_SUBMODULE(class_, m) {
     };
     struct HasOpNewDelBoth {
         std::uint32_t i[8];
-        static void *operator new(size_t s) { py::print("D new", s); return ::operator new(s); }
-        static void *operator new(size_t s, void *ptr) { py::print("D placement-new", s); return ptr; }
-        static void operator delete(void *p) { py::print("D delete"); return ::operator delete(p); }
-        static void operator delete(void *p, size_t s) { py::print("D wrong delete", s); return ::operator delete(p); }
+        static void *operator new(size_t s) {
+            py::print("D new", s);
+            return ::operator new(s);
+        }
+        static void *operator new(size_t s, void *ptr) {
+            py::print("D placement-new", s);
+            return ptr;
+        }
+        static void operator delete(void *p) {
+            py::print("D delete");
+            return ::operator delete(p);
+        }
+        static void operator delete(void *p, size_t s) {
+            py::print("D wrong delete", s);
+            return ::operator delete(p);
+        }
     };
     py::class_<HasOpNewDel>(m, "HasOpNewDel").def(py::init<>());
     py::class_<HasOpNewDelSize>(m, "HasOpNewDelSize").def(py::init<>());
     py::class_<HasOpNewDelBoth>(m, "HasOpNewDelBoth").def(py::init<>());
-    py::class_<AliasedHasOpNewDelSize, PyAliasedHasOpNewDelSize> aliased(m, "AliasedHasOpNewDelSize");
+    py::class_<AliasedHasOpNewDelSize, PyAliasedHasOpNewDelSize> aliased(m,
+                                                                         "AliasedHasOpNewDelSize");
     aliased.def(py::init<>());
     aliased.attr("size_noalias") = py::int_(sizeof(AliasedHasOpNewDelSize));
     aliased.attr("size_alias") = py::int_(sizeof(PyAliasedHasOpNewDelSize));
@@ -346,7 +382,7 @@ TEST_SUBMODULE(class_, m) {
         // [workaround(intel)] = default does not work here
         // Removing or defaulting this destructor results in linking errors with the Intel compiler
         // (in Debug builds only, tested with icpc (ICC) 2021.1 Beta 20200827)
-        ~PublicistB() override {};  // NOLINT(modernize-use-equals-default)
+        ~PublicistB() override{}; // NOLINT(modernize-use-equals-default)
         using ProtectedB::foo;
     };
 
@@ -396,8 +432,8 @@ TEST_SUBMODULE(class_, m) {
     py::class_<Nested>(base, "Nested")
         .def(py::init<>())
         .def("fn", [](Nested &, int, NestBase &, Nested &) {})
-        .def("fa", [](Nested &, int, NestBase &, Nested &) {},
-                "a"_a, "b"_a, "c"_a);
+        .def(
+            "fa", [](Nested &, int, NestBase &, Nested &) {}, "a"_a, "b"_a, "c"_a);
     base.def("g", [](NestBase &, Nested &) {});
     base.def("h", []() { return NestBase(); });
 
@@ -407,21 +443,21 @@ TEST_SUBMODULE(class_, m) {
     // generate a useful error message
 
     struct NotRegistered {};
-    struct StringWrapper { std::string str; };
+    struct StringWrapper {
+        std::string str;
+    };
     m.def("test_error_after_conversions", [](int) {});
     m.def("test_error_after_conversions",
           [](const StringWrapper &) -> NotRegistered { return {}; });
     py::class_<StringWrapper>(m, "StringWrapper").def(py::init<std::string>());
     py::implicitly_convertible<std::string, StringWrapper>();
 
-    #if defined(PYBIND11_CPP17)
-        struct alignas(1024) Aligned {
-            std::uintptr_t ptr() const { return (uintptr_t) this; }
-        };
-        py::class_<Aligned>(m, "Aligned")
-            .def(py::init<>())
-            .def("ptr", &Aligned::ptr);
-    #endif
+#if defined(PYBIND11_CPP17)
+    struct alignas(1024) Aligned {
+        std::uintptr_t ptr() const { return (uintptr_t) this; }
+    };
+    py::class_<Aligned>(m, "Aligned").def(py::init<>()).def("ptr", &Aligned::ptr);
+#endif
 
     // test_final
     struct IsFinal final {};
@@ -434,9 +470,7 @@ TEST_SUBMODULE(class_, m) {
     // test_exception_rvalue_abort
     struct PyPrintDestructor {
         PyPrintDestructor() = default;
-        ~PyPrintDestructor() {
-            py::print("Print from destructor");
-        }
+        ~PyPrintDestructor() { py::print("Print from destructor"); }
         void throw_something() { throw std::runtime_error("error"); }
     };
     py::class_<PyPrintDestructor>(m, "PyPrintDestructor")
@@ -450,8 +484,7 @@ TEST_SUBMODULE(class_, m) {
         .def(py::init([]() { return &samePointer; }));
 
     struct Empty {};
-    py::class_<Empty>(m, "Empty")
-        .def(py::init<>());
+    py::class_<Empty>(m, "Empty").def(py::init<>());
 
     // test_base_and_derived_nested_scope
     struct BaseWithNested {
@@ -493,12 +526,15 @@ TEST_SUBMODULE(class_, m) {
     });
 }
 
-template <int N> class BreaksBase { public:
+template <int N>
+class BreaksBase {
+public:
     virtual ~BreaksBase() = default;
     BreaksBase() = default;
-    BreaksBase(const BreaksBase&) = delete;
+    BreaksBase(const BreaksBase &) = delete;
 };
-template <int N> class BreaksTramp : public BreaksBase<N> {};
+template <int N>
+class BreaksTramp : public BreaksBase<N> {};
 // These should all compile just fine:
 using DoesntBreak1 = py::class_<BreaksBase<1>, std::unique_ptr<BreaksBase<1>>, BreaksTramp<1>>;
 using DoesntBreak2 = py::class_<BreaksBase<2>, BreaksTramp<2>, std::unique_ptr<BreaksBase<2>>>;
@@ -508,43 +544,72 @@ using DoesntBreak5 = py::class_<BreaksBase<5>>;
 using DoesntBreak6 = py::class_<BreaksBase<6>, std::shared_ptr<BreaksBase<6>>, BreaksTramp<6>>;
 using DoesntBreak7 = py::class_<BreaksBase<7>, BreaksTramp<7>, std::shared_ptr<BreaksBase<7>>>;
 using DoesntBreak8 = py::class_<BreaksBase<8>, std::shared_ptr<BreaksBase<8>>>;
-#define CHECK_BASE(N) static_assert(std::is_same<typename DoesntBreak##N::type, BreaksBase<(N)>>::value, \
-        "DoesntBreak" #N " has wrong type!")
-CHECK_BASE(1); CHECK_BASE(2); CHECK_BASE(3); CHECK_BASE(4); CHECK_BASE(5); CHECK_BASE(6); CHECK_BASE(7); CHECK_BASE(8);
-#define CHECK_ALIAS(N) static_assert(DoesntBreak##N::has_alias && std::is_same<typename DoesntBreak##N::type_alias, BreaksTramp<(N)>>::value, \
+#define CHECK_BASE(N)                                                                             \
+    static_assert(std::is_same<typename DoesntBreak##N::type, BreaksBase<(N)>>::value,            \
+                  "DoesntBreak" #N " has wrong type!")
+CHECK_BASE(1);
+CHECK_BASE(2);
+CHECK_BASE(3);
+CHECK_BASE(4);
+CHECK_BASE(5);
+CHECK_BASE(6);
+CHECK_BASE(7);
+CHECK_BASE(8);
+#define CHECK_ALIAS(N)                                                                            \
+    static_assert(                                                                                \
+        DoesntBreak##N::has_alias                                                                 \
+            && std::is_same<typename DoesntBreak##N::type_alias, BreaksTramp<(N)>>::value,        \
         "DoesntBreak" #N " has wrong type_alias!")
-#define CHECK_NOALIAS(N) static_assert(!DoesntBreak##N::has_alias && std::is_void<typename DoesntBreak##N::type_alias>::value, \
-        "DoesntBreak" #N " has type alias, but shouldn't!")
-CHECK_ALIAS(1); CHECK_ALIAS(2); CHECK_NOALIAS(3); CHECK_ALIAS(4); CHECK_NOALIAS(5); CHECK_ALIAS(6); CHECK_ALIAS(7); CHECK_NOALIAS(8);
-#define CHECK_HOLDER(N, TYPE) static_assert(std::is_same<typename DoesntBreak##N::holder_type, std::TYPE##_ptr<BreaksBase<(N)>>>::value, \
-        "DoesntBreak" #N " has wrong holder_type!")
-CHECK_HOLDER(1, unique); CHECK_HOLDER(2, unique); CHECK_HOLDER(3, unique); CHECK_HOLDER(4, unique); CHECK_HOLDER(5, unique);
-CHECK_HOLDER(6, shared); CHECK_HOLDER(7, shared); CHECK_HOLDER(8, shared);
+#define CHECK_NOALIAS(N)                                                                          \
+    static_assert(!DoesntBreak##N::has_alias                                                      \
+                      && std::is_void<typename DoesntBreak##N::type_alias>::value,                \
+                  "DoesntBreak" #N " has type alias, but shouldn't!")
+CHECK_ALIAS(1);
+CHECK_ALIAS(2);
+CHECK_NOALIAS(3);
+CHECK_ALIAS(4);
+CHECK_NOALIAS(5);
+CHECK_ALIAS(6);
+CHECK_ALIAS(7);
+CHECK_NOALIAS(8);
+#define CHECK_HOLDER(N, TYPE)                                                                     \
+    static_assert(std::is_same<typename DoesntBreak##N::holder_type,                              \
+                               std::TYPE##_ptr<BreaksBase<(N)>>>::value,                          \
+                  "DoesntBreak" #N " has wrong holder_type!")
+CHECK_HOLDER(1, unique);
+CHECK_HOLDER(2, unique);
+CHECK_HOLDER(3, unique);
+CHECK_HOLDER(4, unique);
+CHECK_HOLDER(5, unique);
+CHECK_HOLDER(6, shared);
+CHECK_HOLDER(7, shared);
+CHECK_HOLDER(8, shared);
 
 // There's no nice way to test that these fail because they fail to compile; leave them here,
 // though, so that they can be manually tested by uncommenting them (and seeing that compilation
 // failures occurs).
 
 // We have to actually look into the type: the typedef alone isn't enough to instantiate the type:
-#define CHECK_BROKEN(N) static_assert(std::is_same<typename Breaks##N::type, BreaksBase<-(N)>>::value, \
-        "Breaks1 has wrong type!");
+#define CHECK_BROKEN(N)                                                                           \
+    static_assert(std::is_same<typename Breaks##N::type, BreaksBase<-(N)>>::value,                \
+                  "Breaks1 has wrong type!");
 
 //// Two holder classes:
-//typedef py::class_<BreaksBase<-1>, std::unique_ptr<BreaksBase<-1>>, std::unique_ptr<BreaksBase<-1>>> Breaks1;
-//CHECK_BROKEN(1);
+// typedef py::class_<BreaksBase<-1>, std::unique_ptr<BreaksBase<-1>>,
+// std::unique_ptr<BreaksBase<-1>>> Breaks1; CHECK_BROKEN(1);
 //// Two aliases:
-//typedef py::class_<BreaksBase<-2>, BreaksTramp<-2>, BreaksTramp<-2>> Breaks2;
-//CHECK_BROKEN(2);
+// typedef py::class_<BreaksBase<-2>, BreaksTramp<-2>, BreaksTramp<-2>> Breaks2;
+// CHECK_BROKEN(2);
 //// Holder + 2 aliases
-//typedef py::class_<BreaksBase<-3>, std::unique_ptr<BreaksBase<-3>>, BreaksTramp<-3>, BreaksTramp<-3>> Breaks3;
-//CHECK_BROKEN(3);
+// typedef py::class_<BreaksBase<-3>, std::unique_ptr<BreaksBase<-3>>, BreaksTramp<-3>,
+// BreaksTramp<-3>> Breaks3; CHECK_BROKEN(3);
 //// Alias + 2 holders
-//typedef py::class_<BreaksBase<-4>, std::unique_ptr<BreaksBase<-4>>, BreaksTramp<-4>, std::shared_ptr<BreaksBase<-4>>> Breaks4;
-//CHECK_BROKEN(4);
+// typedef py::class_<BreaksBase<-4>, std::unique_ptr<BreaksBase<-4>>, BreaksTramp<-4>,
+// std::shared_ptr<BreaksBase<-4>>> Breaks4; CHECK_BROKEN(4);
 //// Invalid option (not a subclass or holder)
-//typedef py::class_<BreaksBase<-5>, BreaksTramp<-4>> Breaks5;
-//CHECK_BROKEN(5);
+// typedef py::class_<BreaksBase<-5>, BreaksTramp<-4>> Breaks5;
+// CHECK_BROKEN(5);
 //// Invalid option: multiple inheritance not supported:
-//template <> struct BreaksBase<-8> : BreaksBase<-6>, BreaksBase<-7> {};
-//typedef py::class_<BreaksBase<-8>, BreaksBase<-6>, BreaksBase<-7>> Breaks8;
-//CHECK_BROKEN(8);
+// template <> struct BreaksBase<-8> : BreaksBase<-6>, BreaksBase<-7> {};
+// typedef py::class_<BreaksBase<-8>, BreaksBase<-6>, BreaksBase<-7>> Breaks8;
+// CHECK_BROKEN(8);
diff --git a/tests/test_cmake_build/embed.cpp b/tests/test_cmake_build/embed.cpp
index a3abc8a84d..e700a7c9c2 100644
--- a/tests/test_cmake_build/embed.cpp
+++ b/tests/test_cmake_build/embed.cpp
@@ -8,7 +8,7 @@ PYBIND11_EMBEDDED_MODULE(test_cmake_build, m) {
 int main(int argc, char *argv[]) {
     if (argc != 2)
         throw std::runtime_error("Expected test.py file as the first argument");
-    auto test_py_file = argv[1];
+    auto *test_py_file = argv[1];
 
     py::scoped_interpreter guard{};
 
diff --git a/tests/test_constants_and_functions.cpp b/tests/test_constants_and_functions.cpp
index c0554503fa..7a6dae1a10 100644
--- a/tests/test_constants_and_functions.cpp
+++ b/tests/test_constants_and_functions.cpp
@@ -12,20 +12,14 @@
 
 enum MyEnum { EFirstEntry = 1, ESecondEntry };
 
-std::string test_function1() {
-    return "test_function()";
-}
+std::string test_function1() { return "test_function()"; }
 
-std::string test_function2(MyEnum k) {
-    return "test_function(enum=" + std::to_string(k) + ")";
-}
+std::string test_function2(MyEnum k) { return "test_function(enum=" + std::to_string(k) + ")"; }
 
-std::string test_function3(int i) {
-    return "test_function(" + std::to_string(i) + ")";
-}
+std::string test_function3(int i) { return "test_function(" + std::to_string(i) + ")"; }
 
-py::str test_function4()           { return "test_function()"; }
-py::str test_function4(char *)     { return "test_function(char *)"; }
+py::str test_function4() { return "test_function()"; }
+py::str test_function4(char *) { return "test_function(char *)"; }
 py::str test_function4(int, float) { return "test_function(int, float)"; }
 py::str test_function4(float, int) { return "test_function(float, int)"; }
 
@@ -44,50 +38,50 @@ std::string print_bytes(const py::bytes &bytes) {
     return ret;
 }
 
-// Test that we properly handle C++17 exception specifiers (which are part of the function signature
-// in C++17).  These should all still work before C++17, but don't affect the function signature.
+// Test that we properly handle C++17 exception specifiers (which are part of the function
+// signature in C++17).  These should all still work before C++17, but don't affect the function
+// signature.
 namespace test_exc_sp {
 // [workaround(intel)] Unable to use noexcept instead of noexcept(true)
 // Make the f1 test basically the same as the f2 test in C++17 mode for the Intel compiler as
 // it fails to compile with a plain noexcept (tested with icc (ICC) 2021.1 Beta 20200827).
 #if defined(__INTEL_COMPILER) && defined(PYBIND11_CPP17)
-int f1(int x) noexcept(true) { return x+1; }
+int f1(int x) noexcept(true) { return x + 1; }
 #else
-int f1(int x) noexcept { return x+1; }
+int f1(int x) noexcept { return x + 1; }
 #endif
-int f2(int x) noexcept(true) { return x+2; }
-int f3(int x) noexcept(false) { return x+3; }
+int f2(int x) noexcept(true) { return x + 2; }
+int f3(int x) noexcept(false) { return x + 3; }
 #if defined(__GNUG__) && !defined(__INTEL_COMPILER)
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wdeprecated"
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wdeprecated"
 #endif
 // NOLINTNEXTLINE(modernize-use-noexcept)
-int f4(int x) throw() { return x+4; } // Deprecated equivalent to noexcept(true)
+int f4(int x) throw() { return x + 4; } // Deprecated equivalent to noexcept(true)
 #if defined(__GNUG__) && !defined(__INTEL_COMPILER)
-#  pragma GCC diagnostic pop
+#    pragma GCC diagnostic pop
 #endif
 struct C {
-    int m1(int x) noexcept { return x-1; }
-    int m2(int x) const noexcept { return x-2; }
-    int m3(int x) noexcept(true) { return x-3; }
-    int m4(int x) const noexcept(true) { return x-4; }
-    int m5(int x) noexcept(false) { return x-5; }
-    int m6(int x) const noexcept(false) { return x-6; }
+    int m1(int x) noexcept { return x - 1; }
+    int m2(int x) const noexcept { return x - 2; }
+    int m3(int x) noexcept(true) { return x - 3; }
+    int m4(int x) const noexcept(true) { return x - 4; }
+    int m5(int x) noexcept(false) { return x - 5; }
+    int m6(int x) const noexcept(false) { return x - 6; }
 #if defined(__GNUG__) && !defined(__INTEL_COMPILER)
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wdeprecated"
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wdeprecated"
 #endif
     // NOLINTNEXTLINE(modernize-use-noexcept)
     int m7(int x) throw() { return x - 7; }
     // NOLINTNEXTLINE(modernize-use-noexcept)
     int m8(int x) const throw() { return x - 8; }
 #if defined(__GNUG__) && !defined(__INTEL_COMPILER)
-#  pragma GCC diagnostic pop
+#    pragma GCC diagnostic pop
 #endif
 };
 } // namespace test_exc_sp
 
-
 TEST_SUBMODULE(constants_and_functions, m) {
     // test_constants
     m.attr("some_constant") = py::int_(14);
@@ -129,8 +123,7 @@ TEST_SUBMODULE(constants_and_functions, m) {
         .def("m5", &C::m5)
         .def("m6", &C::m6)
         .def("m7", &C::m7)
-        .def("m8", &C::m8)
-        ;
+        .def("m8", &C::m8);
     m.def("f1", f1);
     m.def("f2", f2);
 #if defined(__INTEL_COMPILER)
@@ -150,8 +143,12 @@ TEST_SUBMODULE(constants_and_functions, m) {
         uint64_t zeros[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
     };
     m.def("register_large_capture_with_invalid_arguments", [](py::module_ m) {
-        LargeCapture capture;  // VS 2015's MSVC is acting up if we create the array here
-        m.def("should_raise", [capture](int) { return capture.zeros[9] + 33; }, py::kw_only(), py::arg());
+        LargeCapture capture; // VS 2015's MSVC is acting up if we create the array here
+        m.def(
+            "should_raise",
+            [capture](int) { return capture.zeros[9] + 33; },
+            py::kw_only(),
+            py::arg());
     });
     m.def("register_with_raising_repr", [](py::module_ m, const py::object &default_value) {
         m.def(
diff --git a/tests/test_copy_move.cpp b/tests/test_copy_move.cpp
index 4711a94822..554b263c42 100644
--- a/tests/test_copy_move.cpp
+++ b/tests/test_copy_move.cpp
@@ -8,30 +8,33 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
-#include "constructor_stats.h"
 #include <pybind11/stl.h>
 
+#include "constructor_stats.h"
+#include "pybind11_tests.h"
+
 template <typename derived>
 struct empty {
-    static const derived& get_one() { return instance_; }
+    static const derived &get_one() { return instance_; }
     static derived instance_;
 };
 
 struct lacking_copy_ctor : public empty<lacking_copy_ctor> {
     lacking_copy_ctor() = default;
-    lacking_copy_ctor(const lacking_copy_ctor& other) = delete;
+    lacking_copy_ctor(const lacking_copy_ctor &other) = delete;
 };
 
-template <> lacking_copy_ctor empty<lacking_copy_ctor>::instance_ = {};
+template <>
+lacking_copy_ctor empty<lacking_copy_ctor>::instance_ = {};
 
 struct lacking_move_ctor : public empty<lacking_move_ctor> {
     lacking_move_ctor() = default;
-    lacking_move_ctor(const lacking_move_ctor& other) = delete;
-    lacking_move_ctor(lacking_move_ctor&& other) = delete;
+    lacking_move_ctor(const lacking_move_ctor &other) = delete;
+    lacking_move_ctor(lacking_move_ctor &&other) = delete;
 };
 
-template <> lacking_move_ctor empty<lacking_move_ctor>::instance_ = {};
+template <>
+lacking_move_ctor empty<lacking_move_ctor>::instance_ = {};
 
 /* Custom type caster move/copy test classes */
 class MoveOnlyInt {
@@ -66,8 +69,15 @@ class MoveOrCopyInt {
         std::swap(value, m.value);
         return *this;
     }
-    MoveOrCopyInt(const MoveOrCopyInt &c) { print_copy_created(this, c.value); value = c.value; }
-    MoveOrCopyInt &operator=(const MoveOrCopyInt &c) { print_copy_assigned(this, c.value); value = c.value; return *this; }
+    MoveOrCopyInt(const MoveOrCopyInt &c) {
+        print_copy_created(this, c.value);
+        value = c.value;
+    }
+    MoveOrCopyInt &operator=(const MoveOrCopyInt &c) {
+        print_copy_assigned(this, c.value);
+        value = c.value;
+        return *this;
+    }
     ~MoveOrCopyInt() { print_destroyed(this); }
 
     int value;
@@ -76,40 +86,68 @@ class CopyOnlyInt {
 public:
     CopyOnlyInt() { print_default_created(this); }
     explicit CopyOnlyInt(int v) : value{v} { print_created(this, value); }
-    CopyOnlyInt(const CopyOnlyInt &c) { print_copy_created(this, c.value); value = c.value; }
-    CopyOnlyInt &operator=(const CopyOnlyInt &c) { print_copy_assigned(this, c.value); value = c.value; return *this; }
+    CopyOnlyInt(const CopyOnlyInt &c) {
+        print_copy_created(this, c.value);
+        value = c.value;
+    }
+    CopyOnlyInt &operator=(const CopyOnlyInt &c) {
+        print_copy_assigned(this, c.value);
+        value = c.value;
+        return *this;
+    }
     ~CopyOnlyInt() { print_destroyed(this); }
 
     int value;
 };
 PYBIND11_NAMESPACE_BEGIN(pybind11)
 PYBIND11_NAMESPACE_BEGIN(detail)
-template <> struct type_caster<MoveOnlyInt> {
+template <>
+struct type_caster<MoveOnlyInt> {
     PYBIND11_TYPE_CASTER(MoveOnlyInt, const_name("MoveOnlyInt"));
-    bool load(handle src, bool) { value = MoveOnlyInt(src.cast<int>()); return true; }
-    static handle cast(const MoveOnlyInt &m, return_value_policy r, handle p) { return pybind11::cast(m.value, r, p); }
+    bool load(handle src, bool) {
+        value = MoveOnlyInt(src.cast<int>());
+        return true;
+    }
+    static handle cast(const MoveOnlyInt &m, return_value_policy r, handle p) {
+        return pybind11::cast(m.value, r, p);
+    }
 };
 
-template <> struct type_caster<MoveOrCopyInt> {
+template <>
+struct type_caster<MoveOrCopyInt> {
     PYBIND11_TYPE_CASTER(MoveOrCopyInt, const_name("MoveOrCopyInt"));
-    bool load(handle src, bool) { value = MoveOrCopyInt(src.cast<int>()); return true; }
-    static handle cast(const MoveOrCopyInt &m, return_value_policy r, handle p) { return pybind11::cast(m.value, r, p); }
+    bool load(handle src, bool) {
+        value = MoveOrCopyInt(src.cast<int>());
+        return true;
+    }
+    static handle cast(const MoveOrCopyInt &m, return_value_policy r, handle p) {
+        return pybind11::cast(m.value, r, p);
+    }
 };
 
-template <> struct type_caster<CopyOnlyInt> {
+template <>
+struct type_caster<CopyOnlyInt> {
 protected:
     CopyOnlyInt value;
+
 public:
     static constexpr auto name = const_name("CopyOnlyInt");
-    bool load(handle src, bool) { value = CopyOnlyInt(src.cast<int>()); return true; }
-    static handle cast(const CopyOnlyInt &m, return_value_policy r, handle p) { return pybind11::cast(m.value, r, p); }
+    bool load(handle src, bool) {
+        value = CopyOnlyInt(src.cast<int>());
+        return true;
+    }
+    static handle cast(const CopyOnlyInt &m, return_value_policy r, handle p) {
+        return pybind11::cast(m.value, r, p);
+    }
     static handle cast(const CopyOnlyInt *src, return_value_policy policy, handle parent) {
-        if (!src) return none().release();
+        if (!src)
+            return none().release();
         return cast(*src, policy, parent);
     }
     explicit operator CopyOnlyInt *() { return &value; }
     explicit operator CopyOnlyInt &() { return value; }
-    template <typename T> using cast_op_type = pybind11::detail::cast_op_type<T>;
+    template <typename T>
+    using cast_op_type = pybind11::detail::cast_op_type<T>;
 };
 PYBIND11_NAMESPACE_END(detail)
 PYBIND11_NAMESPACE_END(pybind11)
@@ -117,23 +155,21 @@ PYBIND11_NAMESPACE_END(pybind11)
 TEST_SUBMODULE(copy_move_policies, m) {
     // test_lacking_copy_ctor
     py::class_<lacking_copy_ctor>(m, "lacking_copy_ctor")
-        .def_static("get_one", &lacking_copy_ctor::get_one,
-                    py::return_value_policy::copy);
+        .def_static("get_one", &lacking_copy_ctor::get_one, py::return_value_policy::copy);
     // test_lacking_move_ctor
     py::class_<lacking_move_ctor>(m, "lacking_move_ctor")
-        .def_static("get_one", &lacking_move_ctor::get_one,
-                    py::return_value_policy::move);
+        .def_static("get_one", &lacking_move_ctor::get_one, py::return_value_policy::move);
 
     // test_move_and_copy_casts
     // NOLINTNEXTLINE(performance-unnecessary-value-param)
     m.def("move_and_copy_casts", [](const py::object &o) {
         int r = 0;
         r += py::cast<MoveOrCopyInt>(o).value; /* moves */
-        r += py::cast<MoveOnlyInt>(o).value; /* moves */
-        r += py::cast<CopyOnlyInt>(o).value; /* copies */
-        auto m1(py::cast<MoveOrCopyInt>(o)); /* moves */
-        auto m2(py::cast<MoveOnlyInt>(o)); /* moves */
-        auto m3(py::cast<CopyOnlyInt>(o)); /* copies */
+        r += py::cast<MoveOnlyInt>(o).value;   /* moves */
+        r += py::cast<CopyOnlyInt>(o).value;   /* copies */
+        auto m1(py::cast<MoveOrCopyInt>(o));   /* moves */
+        auto m2(py::cast<MoveOnlyInt>(o));     /* moves */
+        auto m3(py::cast<CopyOnlyInt>(o));     /* copies */
         r += m1.value + m2.value + m3.value;
 
         return r;
@@ -147,28 +183,34 @@ TEST_SUBMODULE(copy_move_policies, m) {
     // Changing this breaks the existing test: needs careful review.
     // NOLINTNEXTLINE(performance-unnecessary-value-param)
     m.def("copy_only", [](CopyOnlyInt m) { return m.value; });
-    m.def("move_pair", [](std::pair<MoveOnlyInt, MoveOrCopyInt> p) {
-        return p.first.value + p.second.value;
-    });
+    m.def("move_pair",
+          [](std::pair<MoveOnlyInt, MoveOrCopyInt> p) { return p.first.value + p.second.value; });
     m.def("move_tuple", [](std::tuple<MoveOnlyInt, MoveOrCopyInt, MoveOnlyInt> t) {
         return std::get<0>(t).value + std::get<1>(t).value + std::get<2>(t).value;
     });
     m.def("copy_tuple", [](std::tuple<CopyOnlyInt, CopyOnlyInt> t) {
         return std::get<0>(t).value + std::get<1>(t).value;
     });
-    m.def("move_copy_nested", [](std::pair<MoveOnlyInt, std::pair<std::tuple<MoveOrCopyInt, CopyOnlyInt, std::tuple<MoveOnlyInt>>, MoveOrCopyInt>> x) {
-        return x.first.value + std::get<0>(x.second.first).value + std::get<1>(x.second.first).value +
-            std::get<0>(std::get<2>(x.second.first)).value + x.second.second.value;
-    });
+    m.def("move_copy_nested",
+          [](std::pair<MoveOnlyInt,
+                       std::pair<std::tuple<MoveOrCopyInt, CopyOnlyInt, std::tuple<MoveOnlyInt>>,
+                                 MoveOrCopyInt>> x) {
+              return x.first.value + std::get<0>(x.second.first).value
+                     + std::get<1>(x.second.first).value
+                     + std::get<0>(std::get<2>(x.second.first)).value + x.second.second.value;
+          });
     m.def("move_and_copy_cstats", []() {
         ConstructorStats::gc();
         // Reset counts to 0 so that previous tests don't affect later ones:
         auto &mc = ConstructorStats::get<MoveOrCopyInt>();
-        mc.move_assignments = mc.move_constructions = mc.copy_assignments = mc.copy_constructions = 0;
+        mc.move_assignments = mc.move_constructions = mc.copy_assignments = mc.copy_constructions
+            = 0;
         auto &mo = ConstructorStats::get<MoveOnlyInt>();
-        mo.move_assignments = mo.move_constructions = mo.copy_assignments = mo.copy_constructions = 0;
+        mo.move_assignments = mo.move_constructions = mo.copy_assignments = mo.copy_constructions
+            = 0;
         auto &co = ConstructorStats::get<CopyOnlyInt>();
-        co.move_assignments = co.move_constructions = co.copy_assignments = co.copy_constructions = 0;
+        co.move_assignments = co.move_constructions = co.copy_assignments = co.copy_constructions
+            = 0;
         py::dict d;
         d["MoveOrCopyInt"] = py::cast(mc, py::return_value_policy::reference);
         d["MoveOnlyInt"] = py::cast(mo, py::return_value_policy::reference);
@@ -178,18 +220,13 @@ TEST_SUBMODULE(copy_move_policies, m) {
 #ifdef PYBIND11_HAS_OPTIONAL
     // test_move_and_copy_load_optional
     m.attr("has_optional") = true;
-    m.def("move_optional", [](std::optional<MoveOnlyInt> o) {
-        return o->value;
-    });
-    m.def("move_or_copy_optional", [](std::optional<MoveOrCopyInt> o) {
-        return o->value;
-    });
-    m.def("copy_optional", [](std::optional<CopyOnlyInt> o) {
-        return o->value;
-    });
-    m.def("move_optional_tuple", [](std::optional<std::tuple<MoveOrCopyInt, MoveOnlyInt, CopyOnlyInt>> x) {
-        return std::get<0>(*x).value + std::get<1>(*x).value + std::get<2>(*x).value;
-    });
+    m.def("move_optional", [](std::optional<MoveOnlyInt> o) { return o->value; });
+    m.def("move_or_copy_optional", [](std::optional<MoveOrCopyInt> o) { return o->value; });
+    m.def("copy_optional", [](std::optional<CopyOnlyInt> o) { return o->value; });
+    m.def("move_optional_tuple",
+          [](std::optional<std::tuple<MoveOrCopyInt, MoveOnlyInt, CopyOnlyInt>> x) {
+              return std::get<0>(*x).value + std::get<1>(*x).value + std::get<2>(*x).value;
+          });
 #else
     m.attr("has_optional") = false;
 #endif
@@ -200,6 +237,7 @@ TEST_SUBMODULE(copy_move_policies, m) {
     // added later.
     struct PrivateOpNew {
         int value = 1;
+
     private:
         void *operator new(size_t bytes) {
             void *ptr = std::malloc(bytes);
@@ -210,10 +248,13 @@ TEST_SUBMODULE(copy_move_policies, m) {
     };
     py::class_<PrivateOpNew>(m, "PrivateOpNew").def_readonly("value", &PrivateOpNew::value);
     m.def("private_op_new_value", []() { return PrivateOpNew(); });
-    m.def("private_op_new_reference", []() -> const PrivateOpNew & {
-        static PrivateOpNew x{};
-        return x;
-    }, py::return_value_policy::reference);
+    m.def(
+        "private_op_new_reference",
+        []() -> const PrivateOpNew & {
+            static PrivateOpNew x{};
+            return x;
+        },
+        py::return_value_policy::reference);
 
     // test_move_fallback
     // #389: rvp::move should fall-through to copy on non-movable objects
@@ -223,16 +264,25 @@ TEST_SUBMODULE(copy_move_policies, m) {
         MoveIssue1(const MoveIssue1 &c) = default;
         MoveIssue1(MoveIssue1 &&) = delete;
     };
-    py::class_<MoveIssue1>(m, "MoveIssue1").def(py::init<int>()).def_readwrite("value", &MoveIssue1::v);
+    py::class_<MoveIssue1>(m, "MoveIssue1")
+        .def(py::init<int>())
+        .def_readwrite("value", &MoveIssue1::v);
 
     struct MoveIssue2 {
         int v;
         explicit MoveIssue2(int v) : v{v} {}
         MoveIssue2(MoveIssue2 &&) = default;
     };
-    py::class_<MoveIssue2>(m, "MoveIssue2").def(py::init<int>()).def_readwrite("value", &MoveIssue2::v);
+    py::class_<MoveIssue2>(m, "MoveIssue2")
+        .def(py::init<int>())
+        .def_readwrite("value", &MoveIssue2::v);
 
-    // #2742: Don't expect ownership of raw pointer to `new`ed object to be transferred with `py::return_value_policy::move`
-    m.def("get_moveissue1", [](int i) { return std::unique_ptr<MoveIssue1>(new MoveIssue1(i)); }, py::return_value_policy::move);
-    m.def("get_moveissue2", [](int i) { return MoveIssue2(i); }, py::return_value_policy::move);
+    // #2742: Don't expect ownership of raw pointer to `new`ed object to be transferred with
+    // `py::return_value_policy::move`
+    m.def(
+        "get_moveissue1",
+        [](int i) { return std::unique_ptr<MoveIssue1>(new MoveIssue1(i)); },
+        py::return_value_policy::move);
+    m.def(
+        "get_moveissue2", [](int i) { return MoveIssue2(i); }, py::return_value_policy::move);
 }
diff --git a/tests/test_custom_type_casters.cpp b/tests/test_custom_type_casters.cpp
index 48613ee5a1..1d6341582c 100644
--- a/tests/test_custom_type_casters.cpp
+++ b/tests/test_custom_type_casters.cpp
@@ -7,16 +7,23 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include "constructor_stats.h"
-
+#include "pybind11_tests.h"
 
 // py::arg/py::arg_v testing: these arguments just record their argument when invoked
-class ArgInspector1 { public: std::string arg = "(default arg inspector 1)"; };
-class ArgInspector2 { public: std::string arg = "(default arg inspector 2)"; };
-class ArgAlwaysConverts { };
-namespace pybind11 { namespace detail {
-template <> struct type_caster<ArgInspector1> {
+class ArgInspector1 {
+public:
+    std::string arg = "(default arg inspector 1)";
+};
+class ArgInspector2 {
+public:
+    std::string arg = "(default arg inspector 2)";
+};
+class ArgAlwaysConverts {};
+namespace pybind11 {
+namespace detail {
+template <>
+struct type_caster<ArgInspector1> {
 public:
     // Classic
 #ifdef PYBIND11_DETAIL_UNDERSCORE_BACKWARD_COMPATIBILITY
@@ -26,9 +33,10 @@ template <> struct type_caster<ArgInspector1> {
 #endif
 
     bool load(handle src, bool convert) {
-        value.arg = "loading ArgInspector1 argument " +
-            std::string(convert ? "WITH" : "WITHOUT") + " conversion allowed.  "
-            "Argument value = " + (std::string) str(src);
+        value.arg = "loading ArgInspector1 argument " + std::string(convert ? "WITH" : "WITHOUT")
+                    + " conversion allowed.  "
+                      "Argument value = "
+                    + (std::string) str(src);
         return true;
     }
 
@@ -36,14 +44,16 @@ template <> struct type_caster<ArgInspector1> {
         return str(src.arg).release();
     }
 };
-template <> struct type_caster<ArgInspector2> {
+template <>
+struct type_caster<ArgInspector2> {
 public:
     PYBIND11_TYPE_CASTER(ArgInspector2, const_name("ArgInspector2"));
 
     bool load(handle src, bool convert) {
-        value.arg = "loading ArgInspector2 argument " +
-            std::string(convert ? "WITH" : "WITHOUT") + " conversion allowed.  "
-            "Argument value = " + (std::string) str(src);
+        value.arg = "loading ArgInspector2 argument " + std::string(convert ? "WITH" : "WITHOUT")
+                    + " conversion allowed.  "
+                      "Argument value = "
+                    + (std::string) str(src);
         return true;
     }
 
@@ -51,13 +61,12 @@ template <> struct type_caster<ArgInspector2> {
         return str(src.arg).release();
     }
 };
-template <> struct type_caster<ArgAlwaysConverts> {
+template <>
+struct type_caster<ArgAlwaysConverts> {
 public:
     PYBIND11_TYPE_CASTER(ArgAlwaysConverts, const_name("ArgAlwaysConverts"));
 
-    bool load(handle, bool convert) {
-        return convert;
-    }
+    bool load(handle, bool convert) { return convert; }
 
     static handle cast(const ArgAlwaysConverts &, return_value_policy, handle) {
         return py::none().release();
@@ -73,14 +82,19 @@ class DestructionTester {
     ~DestructionTester() { print_destroyed(this); }
     DestructionTester(const DestructionTester &) { print_copy_created(this); }
     DestructionTester(DestructionTester &&) noexcept { print_move_created(this); }
-    DestructionTester &operator=(const DestructionTester &) { print_copy_assigned(this); return *this; }
+    DestructionTester &operator=(const DestructionTester &) {
+        print_copy_assigned(this);
+        return *this;
+    }
     DestructionTester &operator=(DestructionTester &&) noexcept {
         print_move_assigned(this);
         return *this;
     }
 };
-namespace pybind11 { namespace detail {
-template <> struct type_caster<DestructionTester> {
+namespace pybind11 {
+namespace detail {
+template <>
+struct type_caster<DestructionTester> {
     PYBIND11_TYPE_CASTER(DestructionTester, const_name("DestructionTester"));
     bool load(handle, bool) { return true; }
 
@@ -115,9 +129,14 @@ TEST_SUBMODULE(custom_type_casters, m) {
     py::class_<ArgInspector>(m, "ArgInspector")
         .def(py::init<>())
         .def("f", &ArgInspector::f, py::arg(), py::arg() = ArgAlwaysConverts())
-        .def("g", &ArgInspector::g, "a"_a.noconvert(), "b"_a, "c"_a.noconvert()=13, "d"_a=ArgInspector2(), py::arg() = ArgAlwaysConverts())
-        .def_static("h", &ArgInspector::h, py::arg{}.noconvert(), py::arg() = ArgAlwaysConverts())
-        ;
+        .def("g",
+             &ArgInspector::g,
+             "a"_a.noconvert(),
+             "b"_a,
+             "c"_a.noconvert() = 13,
+             "d"_a = ArgInspector2(),
+             py::arg() = ArgAlwaysConverts())
+        .def_static("h", &ArgInspector::h, py::arg{}.noconvert(), py::arg() = ArgAlwaysConverts());
     m.def(
         "arg_inspect_func",
         [](const ArgInspector2 &a, const ArgInspector1 &b, ArgAlwaysConverts) {
@@ -127,20 +146,33 @@ TEST_SUBMODULE(custom_type_casters, m) {
         py::arg_v(nullptr, ArgInspector1()).noconvert(true),
         py::arg() = ArgAlwaysConverts());
 
-    m.def("floats_preferred", [](double f) { return 0.5 * f; }, "f"_a);
-    m.def("floats_only", [](double f) { return 0.5 * f; }, "f"_a.noconvert());
-    m.def("ints_preferred", [](int i) { return i / 2; }, "i"_a);
-    m.def("ints_only", [](int i) { return i / 2; }, "i"_a.noconvert());
+    m.def(
+        "floats_preferred", [](double f) { return 0.5 * f; }, "f"_a);
+    m.def(
+        "floats_only", [](double f) { return 0.5 * f; }, "f"_a.noconvert());
+    m.def(
+        "ints_preferred", [](int i) { return i / 2; }, "i"_a);
+    m.def(
+        "ints_only", [](int i) { return i / 2; }, "i"_a.noconvert());
 
     // test_custom_caster_destruction
     // Test that `take_ownership` works on types with a custom type caster when given a pointer
 
     // default policy: don't take ownership:
-    m.def("custom_caster_no_destroy", []() { static auto *dt = new DestructionTester(); return dt; });
+    m.def("custom_caster_no_destroy", []() {
+        static auto *dt = new DestructionTester();
+        return dt;
+    });
 
-    m.def("custom_caster_destroy", []() { return new DestructionTester(); },
-            py::return_value_policy::take_ownership); // Takes ownership: destroy when finished
-    m.def("custom_caster_destroy_const", []() -> const DestructionTester * { return new DestructionTester(); },
-            py::return_value_policy::take_ownership); // Likewise (const doesn't inhibit destruction)
-    m.def("destruction_tester_cstats", &ConstructorStats::get<DestructionTester>, py::return_value_policy::reference);
+    m.def(
+        "custom_caster_destroy",
+        []() { return new DestructionTester(); },
+        py::return_value_policy::take_ownership); // Takes ownership: destroy when finished
+    m.def(
+        "custom_caster_destroy_const",
+        []() -> const DestructionTester * { return new DestructionTester(); },
+        py::return_value_policy::take_ownership); // Likewise (const doesn't inhibit destruction)
+    m.def("destruction_tester_cstats",
+          &ConstructorStats::get<DestructionTester>,
+          py::return_value_policy::reference);
 }
diff --git a/tests/test_docstring_options.cpp b/tests/test_docstring_options.cpp
index 8a97af55fc..4d44f4e20d 100644
--- a/tests/test_docstring_options.cpp
+++ b/tests/test_docstring_options.cpp
@@ -15,35 +15,52 @@ TEST_SUBMODULE(docstring_options, m) {
         py::options options;
         options.disable_function_signatures();
 
-        m.def("test_function1", [](int, int) {}, py::arg("a"), py::arg("b"));
-        m.def("test_function2", [](int, int) {}, py::arg("a"), py::arg("b"), "A custom docstring");
-
-        m.def("test_overloaded1", [](int) {}, py::arg("i"), "Overload docstring");
-        m.def("test_overloaded1", [](double) {}, py::arg("d"));
-
-        m.def("test_overloaded2", [](int) {}, py::arg("i"), "overload docstring 1");
-        m.def("test_overloaded2", [](double) {}, py::arg("d"), "overload docstring 2");
-
-        m.def("test_overloaded3", [](int) {}, py::arg("i"));
-        m.def("test_overloaded3", [](double) {}, py::arg("d"), "Overload docstr");
+        m.def(
+            "test_function1", [](int, int) {}, py::arg("a"), py::arg("b"));
+        m.def(
+            "test_function2", [](int, int) {}, py::arg("a"), py::arg("b"), "A custom docstring");
+
+        m.def(
+            "test_overloaded1", [](int) {}, py::arg("i"), "Overload docstring");
+        m.def(
+            "test_overloaded1", [](double) {}, py::arg("d"));
+
+        m.def(
+            "test_overloaded2", [](int) {}, py::arg("i"), "overload docstring 1");
+        m.def(
+            "test_overloaded2", [](double) {}, py::arg("d"), "overload docstring 2");
+
+        m.def(
+            "test_overloaded3", [](int) {}, py::arg("i"));
+        m.def(
+            "test_overloaded3", [](double) {}, py::arg("d"), "Overload docstr");
 
         options.enable_function_signatures();
 
-        m.def("test_function3", [](int, int) {}, py::arg("a"), py::arg("b"));
-        m.def("test_function4", [](int, int) {}, py::arg("a"), py::arg("b"), "A custom docstring");
+        m.def(
+            "test_function3", [](int, int) {}, py::arg("a"), py::arg("b"));
+        m.def(
+            "test_function4", [](int, int) {}, py::arg("a"), py::arg("b"), "A custom docstring");
 
         options.disable_function_signatures().disable_user_defined_docstrings();
 
-        m.def("test_function5", [](int, int) {}, py::arg("a"), py::arg("b"), "A custom docstring");
+        m.def(
+            "test_function5", [](int, int) {}, py::arg("a"), py::arg("b"), "A custom docstring");
 
         {
             py::options nested_options;
             nested_options.enable_user_defined_docstrings();
-            m.def("test_function6", [](int, int) {}, py::arg("a"), py::arg("b"), "A custom docstring");
+            m.def(
+                "test_function6",
+                [](int, int) {},
+                py::arg("a"),
+                py::arg("b"),
+                "A custom docstring");
         }
     }
 
-    m.def("test_function7", [](int, int) {}, py::arg("a"), py::arg("b"), "A custom docstring");
+    m.def(
+        "test_function7", [](int, int) {}, py::arg("a"), py::arg("b"), "A custom docstring");
 
     {
         py::options options;
@@ -63,7 +80,9 @@ TEST_SUBMODULE(docstring_options, m) {
             int getValue() const { return value; }
         };
         py::class_<DocstringTestFoo>(m, "DocstringTestFoo", "This is a class docstring")
-            .def_property("value_prop", &DocstringTestFoo::getValue, &DocstringTestFoo::setValue, "This is a property docstring")
-        ;
+            .def_property("value_prop",
+                          &DocstringTestFoo::getValue,
+                          &DocstringTestFoo::setValue,
+                          "This is a property docstring");
     }
 }
diff --git a/tests/test_eigen.cpp b/tests/test_eigen.cpp
index d22a94a1a1..7624bf1c5e 100644
--- a/tests/test_eigen.cpp
+++ b/tests/test_eigen.cpp
@@ -7,29 +7,30 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
-#include "constructor_stats.h"
 #include <pybind11/eigen.h>
 #include <pybind11/stl.h>
 
+#include "constructor_stats.h"
+#include "pybind11_tests.h"
+
 #if defined(_MSC_VER)
-#if _MSC_VER < 1910  // VS 2015's MSVC
-#  pragma warning(disable: 4127) // C4127: conditional expression is constant
-#endif
-#  pragma warning(disable: 4996) // C4996: std::unary_negation is deprecated
+#    if _MSC_VER < 1910                 // VS 2015's MSVC
+#        pragma warning(disable : 4127) // C4127: conditional expression is constant
+#    endif
+#    pragma warning(disable : 4996) // C4996: std::unary_negation is deprecated
 #endif
 
 #include <Eigen/Cholesky>
 
 using MatrixXdR = Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor>;
 
-
-
 // Sets/resets a testing reference matrix to have values of 10*r + c, where r and c are the
 // (1-based) row/column number.
-template <typename M> void reset_ref(M &x) {
-    for (int i = 0; i < x.rows(); i++) for (int j = 0; j < x.cols(); j++)
-        x(i, j) = 11 + 10*i + j;
+template <typename M>
+void reset_ref(M &x) {
+    for (int i = 0; i < x.rows(); i++)
+        for (int j = 0; j < x.cols(); j++)
+            x(i, j) = 11 + 10 * i + j;
 }
 
 // Returns a static, column-major matrix
@@ -61,11 +62,12 @@ double get_elem(const Eigen::Ref<const Eigen::MatrixXd> &m) { return m(2, 1); };
 
 // Returns a matrix with 10*r + 100*c added to each matrix element (to help test that the matrix
 // reference is referencing rows/columns correctly).
-template <typename MatrixArgType> Eigen::MatrixXd adjust_matrix(MatrixArgType m) {
+template <typename MatrixArgType>
+Eigen::MatrixXd adjust_matrix(MatrixArgType m) {
     Eigen::MatrixXd ret(m);
     for (int c = 0; c < m.cols(); c++)
         for (int r = 0; r < m.rows(); r++)
-            ret(r, c) += 10*r + 100*c;  // NOLINT(clang-analyzer-core.uninitialized.Assign)
+            ret(r, c) += 10 * r + 100 * c; // NOLINT(clang-analyzer-core.uninitialized.Assign)
     return ret;
 }
 
@@ -92,8 +94,10 @@ TEST_SUBMODULE(eigen, m) {
 
     // various tests
     m.def("double_col", [](const Eigen::VectorXf &x) -> Eigen::VectorXf { return 2.0f * x; });
-    m.def("double_row", [](const Eigen::RowVectorXf &x) -> Eigen::RowVectorXf { return 2.0f * x; });
-    m.def("double_complex", [](const Eigen::VectorXcf &x) -> Eigen::VectorXcf { return 2.0f * x; });
+    m.def("double_row",
+          [](const Eigen::RowVectorXf &x) -> Eigen::RowVectorXf { return 2.0f * x; });
+    m.def("double_complex",
+          [](const Eigen::VectorXcf &x) -> Eigen::VectorXcf { return 2.0f * x; });
     m.def("double_threec", [](py::EigenDRef<Eigen::Vector3f> x) { x *= 2; });
     m.def("double_threer", [](py::EigenDRef<Eigen::RowVector3f> x) { x *= 2; });
     m.def("double_mat_cm", [](const Eigen::MatrixXf &x) -> Eigen::MatrixXf { return 2.0f * x; });
@@ -103,19 +107,22 @@ TEST_SUBMODULE(eigen, m) {
     // Different ways of passing via Eigen::Ref; the first and second are the Eigen-recommended
     m.def("cholesky1",
           [](const Eigen::Ref<MatrixXdR> &x) -> Eigen::MatrixXd { return x.llt().matrixL(); });
-    m.def("cholesky2", [](const Eigen::Ref<const MatrixXdR> &x) -> Eigen::MatrixXd { return x.llt().matrixL(); });
-    m.def("cholesky3", [](const Eigen::Ref<MatrixXdR> &x) -> Eigen::MatrixXd { return x.llt().matrixL(); });
+    m.def("cholesky2", [](const Eigen::Ref<const MatrixXdR> &x) -> Eigen::MatrixXd {
+        return x.llt().matrixL();
+    });
+    m.def("cholesky3",
+          [](const Eigen::Ref<MatrixXdR> &x) -> Eigen::MatrixXd { return x.llt().matrixL(); });
     m.def("cholesky4", [](const Eigen::Ref<const MatrixXdR> &x) -> Eigen::MatrixXd {
         return x.llt().matrixL();
     });
 
     // test_eigen_ref_mutators
-    // Mutators: these add some value to the given element using Eigen, but Eigen should be mapping into
-    // the numpy array data and so the result should show up there.  There are three versions: one that
-    // works on a contiguous-row matrix (numpy's default), one for a contiguous-column matrix, and one
-    // for any matrix.
-    auto add_rm = [](Eigen::Ref<MatrixXdR> x, int r, int c, double v) { x(r,c) += v; };
-    auto add_cm = [](Eigen::Ref<Eigen::MatrixXd> x, int r, int c, double v) { x(r,c) += v; };
+    // Mutators: these add some value to the given element using Eigen, but Eigen should be mapping
+    // into the numpy array data and so the result should show up there.  There are three versions:
+    // one that works on a contiguous-row matrix (numpy's default), one for a contiguous-column
+    // matrix, and one for any matrix.
+    auto add_rm = [](Eigen::Ref<MatrixXdR> x, int r, int c, double v) { x(r, c) += v; };
+    auto add_cm = [](Eigen::Ref<Eigen::MatrixXd> x, int r, int c, double v) { x(r, c) += v; };
 
     // Mutators (Eigen maps into numpy variables):
     m.def("add_rm", add_rm); // Only takes row-contiguous
@@ -126,7 +133,8 @@ TEST_SUBMODULE(eigen, m) {
     m.def("add2", add_cm);
     m.def("add2", add_rm);
     // This one accepts a matrix of any stride:
-    m.def("add_any", [](py::EigenDRef<Eigen::MatrixXd> x, int r, int c, double v) { x(r,c) += v; });
+    m.def("add_any",
+          [](py::EigenDRef<Eigen::MatrixXd> x, int r, int c, double v) { x(r, c) += v; });
 
     // Return mutable references (numpy maps into eigen variables)
     m.def("get_cm_ref", []() { return Eigen::Ref<Eigen::MatrixXd>(get_cm()); });
@@ -138,45 +146,67 @@ TEST_SUBMODULE(eigen, m) {
     m.def("reset_refs", reset_refs); // Restores get_{cm,rm}_ref to original values
 
     // Increments and returns ref to (same) matrix
-    m.def("incr_matrix", [](Eigen::Ref<Eigen::MatrixXd> m, double v) {
-        m += Eigen::MatrixXd::Constant(m.rows(), m.cols(), v);
-        return m;
-    }, py::return_value_policy::reference);
+    m.def(
+        "incr_matrix",
+        [](Eigen::Ref<Eigen::MatrixXd> m, double v) {
+            m += Eigen::MatrixXd::Constant(m.rows(), m.cols(), v);
+            return m;
+        },
+        py::return_value_policy::reference);
 
     // Same, but accepts a matrix of any strides
-    m.def("incr_matrix_any", [](py::EigenDRef<Eigen::MatrixXd> m, double v) {
-        m += Eigen::MatrixXd::Constant(m.rows(), m.cols(), v);
-        return m;
-    }, py::return_value_policy::reference);
+    m.def(
+        "incr_matrix_any",
+        [](py::EigenDRef<Eigen::MatrixXd> m, double v) {
+            m += Eigen::MatrixXd::Constant(m.rows(), m.cols(), v);
+            return m;
+        },
+        py::return_value_policy::reference);
 
     // Returns an eigen slice of even rows
-    m.def("even_rows", [](py::EigenDRef<Eigen::MatrixXd> m) {
-        return py::EigenDMap<Eigen::MatrixXd>(
-                m.data(), (m.rows() + 1) / 2, m.cols(),
+    m.def(
+        "even_rows",
+        [](py::EigenDRef<Eigen::MatrixXd> m) {
+            return py::EigenDMap<Eigen::MatrixXd>(
+                m.data(),
+                (m.rows() + 1) / 2,
+                m.cols(),
                 py::EigenDStride(m.outerStride(), 2 * m.innerStride()));
-    }, py::return_value_policy::reference);
+        },
+        py::return_value_policy::reference);
 
     // Returns an eigen slice of even columns
-    m.def("even_cols", [](py::EigenDRef<Eigen::MatrixXd> m) {
-        return py::EigenDMap<Eigen::MatrixXd>(
-                m.data(), m.rows(), (m.cols() + 1) / 2,
+    m.def(
+        "even_cols",
+        [](py::EigenDRef<Eigen::MatrixXd> m) {
+            return py::EigenDMap<Eigen::MatrixXd>(
+                m.data(),
+                m.rows(),
+                (m.cols() + 1) / 2,
                 py::EigenDStride(2 * m.outerStride(), m.innerStride()));
-    }, py::return_value_policy::reference);
+        },
+        py::return_value_policy::reference);
 
     // Returns diagonals: a vector-like object with an inner stride != 1
     m.def("diagonal", [](const Eigen::Ref<const Eigen::MatrixXd> &x) { return x.diagonal(); });
-    m.def("diagonal_1", [](const Eigen::Ref<const Eigen::MatrixXd> &x) { return x.diagonal<1>(); });
-    m.def("diagonal_n", [](const Eigen::Ref<const Eigen::MatrixXd> &x, int index) { return x.diagonal(index); });
+    m.def("diagonal_1",
+          [](const Eigen::Ref<const Eigen::MatrixXd> &x) { return x.diagonal<1>(); });
+    m.def("diagonal_n",
+          [](const Eigen::Ref<const Eigen::MatrixXd> &x, int index) { return x.diagonal(index); });
 
     // Return a block of a matrix (gives non-standard strides)
-    m.def("block", [](const Eigen::Ref<const Eigen::MatrixXd> &x, int start_row, int start_col, int block_rows, int block_cols) {
-        return x.block(start_row, start_col, block_rows, block_cols);
-    });
+    m.def("block",
+          [](const Eigen::Ref<const Eigen::MatrixXd> &x,
+             int start_row,
+             int start_col,
+             int block_rows,
+             int block_cols) { return x.block(start_row, start_col, block_rows, block_cols); });
 
     // test_eigen_return_references, test_eigen_keepalive
     // return value referencing/copying tests:
     class ReturnTester {
         Eigen::MatrixXd mat = create();
+
     public:
         ReturnTester() { print_created(this); }
         ~ReturnTester() { print_destroyed(this); }
@@ -189,12 +219,24 @@ TEST_SUBMODULE(eigen, m) {
         const Eigen::MatrixXd *viewPtr() { return &mat; }
         Eigen::Ref<Eigen::MatrixXd> ref() { return mat; }
         Eigen::Ref<const Eigen::MatrixXd> refConst() { return mat; }
-        Eigen::Block<Eigen::MatrixXd> block(int r, int c, int nrow, int ncol) { return mat.block(r, c, nrow, ncol); }
-        Eigen::Block<const Eigen::MatrixXd> blockConst(int r, int c, int nrow, int ncol) const { return mat.block(r, c, nrow, ncol); }
-        py::EigenDMap<Eigen::Matrix2d> corners() { return py::EigenDMap<Eigen::Matrix2d>(mat.data(),
-                    py::EigenDStride(mat.outerStride() * (mat.outerSize()-1), mat.innerStride() * (mat.innerSize()-1))); }
-        py::EigenDMap<const Eigen::Matrix2d> cornersConst() const { return py::EigenDMap<const Eigen::Matrix2d>(mat.data(),
-                    py::EigenDStride(mat.outerStride() * (mat.outerSize()-1), mat.innerStride() * (mat.innerSize()-1))); }
+        Eigen::Block<Eigen::MatrixXd> block(int r, int c, int nrow, int ncol) {
+            return mat.block(r, c, nrow, ncol);
+        }
+        Eigen::Block<const Eigen::MatrixXd> blockConst(int r, int c, int nrow, int ncol) const {
+            return mat.block(r, c, nrow, ncol);
+        }
+        py::EigenDMap<Eigen::Matrix2d> corners() {
+            return py::EigenDMap<Eigen::Matrix2d>(
+                mat.data(),
+                py::EigenDStride(mat.outerStride() * (mat.outerSize() - 1),
+                                 mat.innerStride() * (mat.innerSize() - 1)));
+        }
+        py::EigenDMap<const Eigen::Matrix2d> cornersConst() const {
+            return py::EigenDMap<const Eigen::Matrix2d>(
+                mat.data(),
+                py::EigenDStride(mat.outerStride() * (mat.outerSize() - 1),
+                                 mat.innerStride() * (mat.innerSize() - 1)));
+        }
     };
     using rvp = py::return_value_policy;
     py::class_<ReturnTester>(m, "ReturnTester")
@@ -205,9 +247,9 @@ TEST_SUBMODULE(eigen, m) {
         .def("get_ptr", &ReturnTester::getPtr, rvp::reference_internal)
         .def("view", &ReturnTester::view, rvp::reference_internal)
         .def("view_ptr", &ReturnTester::view, rvp::reference_internal)
-        .def("copy_get", &ReturnTester::get)   // Default rvp: copy
-        .def("copy_view", &ReturnTester::view) //         "
-        .def("ref", &ReturnTester::ref) // Default for Ref is to reference
+        .def("copy_get", &ReturnTester::get)       // Default rvp: copy
+        .def("copy_view", &ReturnTester::view)     //         "
+        .def("ref", &ReturnTester::ref)            // Default for Ref is to reference
         .def("ref_const", &ReturnTester::refConst) // Likewise, but const
         .def("ref_safe", &ReturnTester::ref, rvp::reference_internal)
         .def("ref_const_safe", &ReturnTester::refConst, rvp::reference_internal)
@@ -218,33 +260,28 @@ TEST_SUBMODULE(eigen, m) {
         .def("block_const", &ReturnTester::blockConst, rvp::reference_internal)
         .def("copy_block", &ReturnTester::block, rvp::copy)
         .def("corners", &ReturnTester::corners, rvp::reference_internal)
-        .def("corners_const", &ReturnTester::cornersConst, rvp::reference_internal)
-        ;
+        .def("corners_const", &ReturnTester::cornersConst, rvp::reference_internal);
 
     // test_special_matrix_objects
     // Returns a DiagonalMatrix with diagonal (1,2,3,...)
     m.def("incr_diag", [](int k) {
         Eigen::DiagonalMatrix<int, Eigen::Dynamic> m(k);
-        for (int i = 0; i < k; i++) m.diagonal()[i] = i+1;
+        for (int i = 0; i < k; i++)
+            m.diagonal()[i] = i + 1;
         return m;
     });
 
     // Returns a SelfAdjointView referencing the lower triangle of m
-    m.def("symmetric_lower", [](const Eigen::MatrixXi &m) {
-            return m.selfadjointView<Eigen::Lower>();
-    });
+    m.def("symmetric_lower",
+          [](const Eigen::MatrixXi &m) { return m.selfadjointView<Eigen::Lower>(); });
     // Returns a SelfAdjointView referencing the lower triangle of m
-    m.def("symmetric_upper", [](const Eigen::MatrixXi &m) {
-            return m.selfadjointView<Eigen::Upper>();
-    });
+    m.def("symmetric_upper",
+          [](const Eigen::MatrixXi &m) { return m.selfadjointView<Eigen::Upper>(); });
 
     // Test matrix for various functions below.
     Eigen::MatrixXf mat(5, 6);
-    mat << 0,  3,  0,  0,  0, 11,
-           22, 0,  0,  0, 17, 11,
-           7,  5,  0,  1,  0, 11,
-           0,  0,  0,  0,  0, 11,
-           0,  0, 14,  0,  8, 11;
+    mat << 0, 3, 0, 0, 0, 11, 22, 0, 0, 0, 17, 11, 7, 5, 0, 1, 0, 11, 0, 0, 0, 0, 0, 11, 0, 0, 14,
+        0, 8, 11;
 
     // test_fixed, and various other tests
     m.def("fixed_r", [mat]() -> FixedMatrixR { return FixedMatrixR(mat); });
@@ -269,7 +306,8 @@ TEST_SUBMODULE(eigen, m) {
         // NOLINTNEXTLINE(clang-analyzer-core.uninitialized.UndefReturn)
         return Eigen::SparseView<Eigen::MatrixXf>(mat);
     });
-    m.def("sparse_c", [mat]() -> SparseMatrixC { return Eigen::SparseView<Eigen::MatrixXf>(mat); });
+    m.def("sparse_c",
+          [mat]() -> SparseMatrixC { return Eigen::SparseView<Eigen::MatrixXf>(mat); });
     m.def("sparse_copy_r", [](const SparseMatrixR &m) -> SparseMatrixR { return m; });
     m.def("sparse_copy_c", [](const SparseMatrixC &m) -> SparseMatrixC { return m; });
     // test_partially_fixed
@@ -283,7 +321,8 @@ TEST_SUBMODULE(eigen, m) {
     m.def("cpp_copy", [](py::handle m) { return m.cast<Eigen::MatrixXd>()(1, 0); });
     m.def("cpp_ref_c", [](py::handle m) { return m.cast<Eigen::Ref<Eigen::MatrixXd>>()(1, 0); });
     m.def("cpp_ref_r", [](py::handle m) { return m.cast<Eigen::Ref<MatrixXdR>>()(1, 0); });
-    m.def("cpp_ref_any", [](py::handle m) { return m.cast<py::EigenDRef<Eigen::MatrixXd>>()(1, 0); });
+    m.def("cpp_ref_any",
+          [](py::handle m) { return m.cast<py::EigenDRef<Eigen::MatrixXd>>()(1, 0); });
 
     // [workaround(intel)] ICC 20/21 breaks with py::arg().stuff, using py::arg{}.stuff works.
 
@@ -297,15 +336,23 @@ TEST_SUBMODULE(eigen, m) {
         [](const Eigen::Ref<const Eigen::MatrixXd> &m) -> double { return get_elem(m); },
         py::arg{}.noconvert());
     // Also test a row-major-only no-copy const ref:
-    m.def("get_elem_rm_nocopy", [](Eigen::Ref<const Eigen::Matrix<long, -1, -1, Eigen::RowMajor>> &m) -> long { return m(2, 1); },
-            py::arg{}.noconvert());
+    m.def(
+        "get_elem_rm_nocopy",
+        [](Eigen::Ref<const Eigen::Matrix<long, -1, -1, Eigen::RowMajor>> &m) -> long {
+            return m(2, 1);
+        },
+        py::arg{}.noconvert());
 
     // test_issue738
     // Issue #738: 1xN or Nx1 2D matrices were neither accepted nor properly copied with an
     // incompatible stride value on the length-1 dimension--but that should be allowed (without
     // requiring a copy!) because the stride value can be safely ignored on a size-1 dimension.
-    m.def("iss738_f1", &adjust_matrix<const Eigen::Ref<const Eigen::MatrixXd> &>, py::arg{}.noconvert());
-    m.def("iss738_f2", &adjust_matrix<const Eigen::Ref<const Eigen::Matrix<double, -1, -1, Eigen::RowMajor>> &>, py::arg{}.noconvert());
+    m.def("iss738_f1",
+          &adjust_matrix<const Eigen::Ref<const Eigen::MatrixXd> &>,
+          py::arg{}.noconvert());
+    m.def("iss738_f2",
+          &adjust_matrix<const Eigen::Ref<const Eigen::Matrix<double, -1, -1, Eigen::RowMajor>> &>,
+          py::arg{}.noconvert());
 
     // test_issue1105
     // Issue #1105: when converting from a numpy two-dimensional (Nx1) or (1xN) value into a dense
diff --git a/tests/test_embed/catch.cpp b/tests/test_embed/catch.cpp
index dd137385cb..590256ffb9 100644
--- a/tests/test_embed/catch.cpp
+++ b/tests/test_embed/catch.cpp
@@ -4,9 +4,9 @@
 #include <pybind11/embed.h>
 
 #ifdef _MSC_VER
-// Silence MSVC C++17 deprecation warning from Catch regarding std::uncaught_exceptions (up to catch
-// 2.0.1; this should be fixed in the next catch release after 2.0.1).
-#  pragma warning(disable: 4996)
+// Silence MSVC C++17 deprecation warning from Catch regarding std::uncaught_exceptions (up to
+// catch 2.0.1; this should be fixed in the next catch release after 2.0.1).
+#    pragma warning(disable : 4996)
 #endif
 
 #define CATCH_CONFIG_RUNNER
diff --git a/tests/test_embed/external_module.cpp b/tests/test_embed/external_module.cpp
index 4909522993..5c482fe061 100644
--- a/tests/test_embed/external_module.cpp
+++ b/tests/test_embed/external_module.cpp
@@ -13,11 +13,8 @@ PYBIND11_MODULE(external_module, m) {
         int v;
     };
 
-    py::class_<A>(m, "A")
-        .def(py::init<int>())
-        .def_readwrite("value", &A::v);
+    py::class_<A>(m, "A").def(py::init<int>()).def_readwrite("value", &A::v);
 
-    m.def("internals_at", []() {
-        return reinterpret_cast<uintptr_t>(&py::detail::get_internals());
-    });
+    m.def("internals_at",
+          []() { return reinterpret_cast<uintptr_t>(&py::detail::get_internals()); });
 }
diff --git a/tests/test_embed/test_interpreter.cpp b/tests/test_embed/test_interpreter.cpp
index 508975eb3c..383de01b39 100644
--- a/tests/test_embed/test_interpreter.cpp
+++ b/tests/test_embed/test_interpreter.cpp
@@ -1,13 +1,12 @@
 #include <pybind11/embed.h>
 
 #ifdef _MSC_VER
-// Silence MSVC C++17 deprecation warning from Catch regarding std::uncaught_exceptions (up to catch
-// 2.0.1; this should be fixed in the next catch release after 2.0.1).
-#  pragma warning(disable: 4996)
+// Silence MSVC C++17 deprecation warning from Catch regarding std::uncaught_exceptions (up to
+// catch 2.0.1; this should be fixed in the next catch release after 2.0.1).
+#    pragma warning(disable : 4996)
 #endif
 
 #include <catch.hpp>
-
 #include <cstdlib>
 #include <fstream>
 #include <functional>
@@ -62,14 +61,14 @@ PYBIND11_EMBEDDED_MODULE(widget_module, m) {
 }
 
 PYBIND11_EMBEDDED_MODULE(trampoline_module, m) {
-    py::class_<test_override_cache_helper, test_override_cache_helper_trampoline, std::shared_ptr<test_override_cache_helper>>(m, "test_override_cache_helper")
+    py::class_<test_override_cache_helper,
+               test_override_cache_helper_trampoline,
+               std::shared_ptr<test_override_cache_helper>>(m, "test_override_cache_helper")
         .def(py::init_alias<>())
         .def("func", &test_override_cache_helper::func);
 }
 
-PYBIND11_EMBEDDED_MODULE(throw_exception, ) {
-    throw std::runtime_error("C++ Error");
-}
+PYBIND11_EMBEDDED_MODULE(throw_exception, ) { throw std::runtime_error("C++ Error"); }
 
 PYBIND11_EMBEDDED_MODULE(throw_error_already_set, ) {
     auto d = py::dict();
@@ -80,11 +79,13 @@ TEST_CASE("Pass classes and data between modules defined in C++ and Python") {
     auto module_ = py::module_::import("test_interpreter");
     REQUIRE(py::hasattr(module_, "DerivedWidget"));
 
-    auto locals = py::dict("hello"_a="Hello, World!", "x"_a=5, **module_.attr("__dict__"));
+    auto locals = py::dict("hello"_a = "Hello, World!", "x"_a = 5, **module_.attr("__dict__"));
     py::exec(R"(
         widget = DerivedWidget("{} - {}".format(hello, x))
         message = widget.the_message
-    )", py::globals(), locals);
+    )",
+             py::globals(),
+             locals);
     REQUIRE(locals["message"].cast<std::string>() == "Hello, World! - 5");
 
     auto py_widget = module_.attr("DerivedWidget")("The question");
@@ -124,20 +125,21 @@ TEST_CASE("Override cache") {
 
 TEST_CASE("Import error handling") {
     REQUIRE_NOTHROW(py::module_::import("widget_module"));
-    REQUIRE_THROWS_WITH(py::module_::import("throw_exception"),
-                        "ImportError: C++ Error");
+    REQUIRE_THROWS_WITH(py::module_::import("throw_exception"), "ImportError: C++ Error");
 #if PY_VERSION_HEX >= 0x03030000
     REQUIRE_THROWS_WITH(py::module_::import("throw_error_already_set"),
                         Catch::Contains("ImportError: initialization failed"));
 
-    auto locals = py::dict("is_keyerror"_a=false, "message"_a="not set");
+    auto locals = py::dict("is_keyerror"_a = false, "message"_a = "not set");
     py::exec(R"(
         try:
             import throw_error_already_set
         except ImportError as e:
             is_keyerror = type(e.__cause__) == KeyError
             message = str(e.__cause__)
-    )", py::globals(), locals);
+    )",
+             py::globals(),
+             locals);
     REQUIRE(locals["is_keyerror"].cast<bool>() == true);
     REQUIRE(locals["message"].cast<std::string>() == "'missing'");
 #else
@@ -179,11 +181,12 @@ TEST_CASE("Restart the interpreter") {
     REQUIRE(py::module_::import("widget_module").attr("add")(1, 2).cast<int>() == 3);
     REQUIRE(has_pybind11_internals_builtin());
     REQUIRE(has_pybind11_internals_static());
-    REQUIRE(py::module_::import("external_module").attr("A")(123).attr("value").cast<int>() == 123);
+    REQUIRE(py::module_::import("external_module").attr("A")(123).attr("value").cast<int>()
+            == 123);
 
     // local and foreign module internals should point to the same internals:
-    REQUIRE(reinterpret_cast<uintptr_t>(*py::detail::get_internals_pp()) ==
-            py::module_::import("external_module").attr("internals_at")().cast<uintptr_t>());
+    REQUIRE(reinterpret_cast<uintptr_t>(*py::detail::get_internals_pp())
+            == py::module_::import("external_module").attr("internals_at")().cast<uintptr_t>());
 
     // Restart the interpreter.
     py::finalize_interpreter();
@@ -198,16 +201,19 @@ TEST_CASE("Restart the interpreter") {
     pybind11::detail::get_internals();
     REQUIRE(has_pybind11_internals_builtin());
     REQUIRE(has_pybind11_internals_static());
-    REQUIRE(reinterpret_cast<uintptr_t>(*py::detail::get_internals_pp()) ==
-            py::module_::import("external_module").attr("internals_at")().cast<uintptr_t>());
+    REQUIRE(reinterpret_cast<uintptr_t>(*py::detail::get_internals_pp())
+            == py::module_::import("external_module").attr("internals_at")().cast<uintptr_t>());
 
     // Make sure that an interpreter with no get_internals() created until finalize still gets the
     // internals destroyed
     py::finalize_interpreter();
     py::initialize_interpreter();
     bool ran = false;
-    py::module_::import("__main__").attr("internals_destroy_test") =
-        py::capsule(&ran, [](void *ran) { py::detail::get_internals(); *static_cast<bool *>(ran) = true; });
+    py::module_::import("__main__").attr("internals_destroy_test")
+        = py::capsule(&ran, [](void *ran) {
+              py::detail::get_internals();
+              *static_cast<bool *>(ran) = true;
+          });
     REQUIRE_FALSE(has_pybind11_internals_builtin());
     REQUIRE_FALSE(has_pybind11_internals_static());
     REQUIRE_FALSE(ran);
@@ -240,8 +246,8 @@ TEST_CASE("Subinterpreter") {
     REQUIRE(has_pybind11_internals_static());
 
     /// Create and switch to a subinterpreter.
-    auto main_tstate = PyThreadState_Get();
-    auto sub_tstate = Py_NewInterpreter();
+    auto *main_tstate = PyThreadState_Get();
+    auto *sub_tstate = Py_NewInterpreter();
 
     // Subinterpreters get their own copy of builtins. detail::get_internals() still
     // works by returning from the static variable, i.e. all interpreters share a single
@@ -281,7 +287,7 @@ TEST_CASE("Threads") {
     REQUIRE_FALSE(has_pybind11_internals_static());
 
     constexpr auto num_threads = 10;
-    auto locals = py::dict("count"_a=0);
+    auto locals = py::dict("count"_a = 0);
 
     {
         py::gil_scoped_release gil_release{};
@@ -307,7 +313,10 @@ TEST_CASE("Threads") {
 struct scope_exit {
     std::function<void()> f_;
     explicit scope_exit(std::function<void()> f) noexcept : f_(std::move(f)) {}
-    ~scope_exit() { if (f_) f_(); }
+    ~scope_exit() {
+        if (f_)
+            f_();
+    }
 };
 
 TEST_CASE("Reload module from file") {
@@ -318,9 +327,8 @@ TEST_CASE("Reload module from file") {
     bool dont_write_bytecode = sys.attr("dont_write_bytecode").cast<bool>();
     sys.attr("dont_write_bytecode") = true;
     // Reset the value at scope exit
-    scope_exit reset_dont_write_bytecode([&]() {
-        sys.attr("dont_write_bytecode") = dont_write_bytecode;
-    });
+    scope_exit reset_dont_write_bytecode(
+        [&]() { sys.attr("dont_write_bytecode") = dont_write_bytecode; });
 
     std::string module_name = "test_module_reload";
     std::string module_file = module_name + ".py";
@@ -331,9 +339,7 @@ TEST_CASE("Reload module from file") {
     test_module << "    return 1\n";
     test_module.close();
     // Delete the file at scope exit
-    scope_exit delete_module_file([&]() {
-        std::remove(module_file.c_str());
-    });
+    scope_exit delete_module_file([&]() { std::remove(module_file.c_str()); });
 
     // Import the module from file
     auto module_ = py::module_::import(module_name.c_str());
diff --git a/tests/test_enum.cpp b/tests/test_enum.cpp
index 40c48d412a..2597b275ef 100644
--- a/tests/test_enum.cpp
+++ b/tests/test_enum.cpp
@@ -11,11 +11,7 @@
 
 TEST_SUBMODULE(enums, m) {
     // test_unscoped_enum
-    enum UnscopedEnum {
-        EOne = 1,
-        ETwo,
-        EThree
-    };
+    enum UnscopedEnum { EOne = 1, ETwo, EThree };
     py::enum_<UnscopedEnum>(m, "UnscopedEnum", py::arithmetic(), "An unscoped enumeration")
         .value("EOne", EOne, "Docstring for EOne")
         .value("ETwo", ETwo, "Docstring for ETwo")
@@ -23,10 +19,7 @@ TEST_SUBMODULE(enums, m) {
         .export_values();
 
     // test_scoped_enum
-    enum class ScopedEnum {
-        Two = 2,
-        Three
-    };
+    enum class ScopedEnum { Two = 2, Three };
     py::enum_<ScopedEnum>(m, "ScopedEnum", py::arithmetic())
         .value("Two", ScopedEnum::Two)
         .value("Three", ScopedEnum::Three);
@@ -36,11 +29,7 @@ TEST_SUBMODULE(enums, m) {
     });
 
     // test_binary_operators
-    enum Flags {
-        Read = 4,
-        Write = 2,
-        Execute = 1
-    };
+    enum Flags { Read = 4, Write = 2, Execute = 1 };
     py::enum_<Flags>(m, "Flags", py::arithmetic())
         .value("Read", Flags::Read)
         .value("Write", Flags::Write)
@@ -50,14 +39,9 @@ TEST_SUBMODULE(enums, m) {
     // test_implicit_conversion
     class ClassWithUnscopedEnum {
     public:
-        enum EMode {
-            EFirstMode = 1,
-            ESecondMode
-        };
-
-        static EMode test_function(EMode mode) {
-            return mode;
-        }
+        enum EMode { EFirstMode = 1, ESecondMode };
+
+        static EMode test_function(EMode mode) { return mode; }
     };
     py::class_<ClassWithUnscopedEnum> exenum_class(m, "ClassWithUnscopedEnum");
     exenum_class.def_static("test_function", &ClassWithUnscopedEnum::test_function);
@@ -67,19 +51,17 @@ TEST_SUBMODULE(enums, m) {
         .export_values();
 
     // test_enum_to_int
-    m.def("test_enum_to_int", [](int) { });
-    m.def("test_enum_to_uint", [](uint32_t) { });
-    m.def("test_enum_to_long_long", [](long long) { });
+    m.def("test_enum_to_int", [](int) {});
+    m.def("test_enum_to_uint", [](uint32_t) {});
+    m.def("test_enum_to_long_long", [](long long) {});
 
     // test_duplicate_enum_name
-    enum SimpleEnum
-    {
-        ONE, TWO, THREE
-    };
+    enum SimpleEnum { ONE, TWO, THREE };
 
     m.def("register_bad_enum", [m]() {
         py::enum_<SimpleEnum>(m, "SimpleEnum")
-            .value("ONE", SimpleEnum::ONE)          //NOTE: all value function calls are called with the same first parameter value
+            .value("ONE", SimpleEnum::ONE) // NOTE: all value function calls are called with the
+                                           // same first parameter value
             .value("ONE", SimpleEnum::TWO)
             .value("ONE", SimpleEnum::THREE)
             .export_values();
@@ -90,33 +72,36 @@ TEST_SUBMODULE(enums, m) {
     enum class ScopedShortEnum : short {};
     enum class ScopedLongEnum : long {};
     enum UnscopedUInt64Enum : std::uint64_t {};
-    static_assert(py::detail::all_of<
-        std::is_same<py::enum_<UnscopedUCharEnum>::Scalar, unsigned char>,
-        std::is_same<py::enum_<ScopedShortEnum>::Scalar, short>,
-        std::is_same<py::enum_<ScopedLongEnum>::Scalar, long>,
-        std::is_same<py::enum_<UnscopedUInt64Enum>::Scalar, std::uint64_t>
-    >::value, "Error during the deduction of enum's scalar type with normal integer underlying");
+    static_assert(
+        py::detail::all_of<
+            std::is_same<py::enum_<UnscopedUCharEnum>::Scalar, unsigned char>,
+            std::is_same<py::enum_<ScopedShortEnum>::Scalar, short>,
+            std::is_same<py::enum_<ScopedLongEnum>::Scalar, long>,
+            std::is_same<py::enum_<UnscopedUInt64Enum>::Scalar, std::uint64_t>>::value,
+        "Error during the deduction of enum's scalar type with normal integer underlying");
 
     // test_enum_scalar_with_char_underlying
-    enum class ScopedCharEnum   : char     { Zero, Positive };
-    enum class ScopedWCharEnum  : wchar_t  { Zero, Positive };
+    enum class ScopedCharEnum : char { Zero, Positive };
+    enum class ScopedWCharEnum : wchar_t { Zero, Positive };
     enum class ScopedChar32Enum : char32_t { Zero, Positive };
     enum class ScopedChar16Enum : char16_t { Zero, Positive };
 
     // test the scalar of char type enums according to chapter 'Character types'
     // from https://en.cppreference.com/w/cpp/language/types
-    static_assert(py::detail::any_of<
-        std::is_same<py::enum_<ScopedCharEnum>::Scalar, signed char>, // e.g. gcc on x86
-        std::is_same<py::enum_<ScopedCharEnum>::Scalar, unsigned char>  // e.g. arm linux
-    >::value, "char should be cast to either signed char or unsigned char");
     static_assert(
-        sizeof(py::enum_<ScopedWCharEnum>::Scalar) == 2 ||
-        sizeof(py::enum_<ScopedWCharEnum>::Scalar) == 4
-    , "wchar_t should be either 16 bits (Windows) or 32 (everywhere else)");
-    static_assert(py::detail::all_of<
-        std::is_same<py::enum_<ScopedChar32Enum>::Scalar, std::uint_least32_t>,
-        std::is_same<py::enum_<ScopedChar16Enum>::Scalar, std::uint_least16_t>
-    >::value, "char32_t, char16_t (and char8_t)'s size, signedness, and alignment is determined");
+        py::detail::any_of<
+            std::is_same<py::enum_<ScopedCharEnum>::Scalar, signed char>,  // e.g. gcc on x86
+            std::is_same<py::enum_<ScopedCharEnum>::Scalar, unsigned char> // e.g. arm linux
+            >::value,
+        "char should be cast to either signed char or unsigned char");
+    static_assert(sizeof(py::enum_<ScopedWCharEnum>::Scalar) == 2
+                      || sizeof(py::enum_<ScopedWCharEnum>::Scalar) == 4,
+                  "wchar_t should be either 16 bits (Windows) or 32 (everywhere else)");
+    static_assert(
+        py::detail::all_of<
+            std::is_same<py::enum_<ScopedChar32Enum>::Scalar, std::uint_least32_t>,
+            std::is_same<py::enum_<ScopedChar16Enum>::Scalar, std::uint_least16_t>>::value,
+        "char32_t, char16_t (and char8_t)'s size, signedness, and alignment is determined");
 #if defined(PYBIND11_HAS_U8STRING)
     enum class ScopedChar8Enum : char8_t { Zero, Positive };
     static_assert(std::is_same<py::enum_<ScopedChar8Enum>::Scalar, unsigned char>::value);
diff --git a/tests/test_eval.cpp b/tests/test_eval.cpp
index 29366f6798..dd8d1ac3b6 100644
--- a/tests/test_eval.cpp
+++ b/tests/test_eval.cpp
@@ -7,10 +7,10 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-
 #include <pybind11/eval.h>
 
 #include "pybind11_tests.h"
+
 #include <utility>
 
 TEST_SUBMODULE(eval_, m) {
@@ -20,16 +20,13 @@ TEST_SUBMODULE(eval_, m) {
 
     m.def("test_eval_statements", [global]() {
         auto local = py::dict();
-        local["call_test"] = py::cpp_function([&]() -> int {
-            return 42;
-        });
+        local["call_test"] = py::cpp_function([&]() -> int { return 42; });
 
         // Regular string literal
-        py::exec(
-            "message = 'Hello World!'\n"
-            "x = call_test()",
-            global, local
-        );
+        py::exec("message = 'Hello World!'\n"
+                 "x = call_test()",
+                 global,
+                 local);
 
         // Multi-line raw string literal
         py::exec(R"(
@@ -37,8 +34,9 @@ TEST_SUBMODULE(eval_, m) {
                 print(message)
             else:
                 raise RuntimeError
-            )", global, local
-        );
+            )",
+                 global,
+                 local);
         auto x = local["x"].cast<int>();
 
         return x == 42;
@@ -53,9 +51,7 @@ TEST_SUBMODULE(eval_, m) {
 
     m.def("test_eval_single_statement", []() {
         auto local = py::dict();
-        local["call_test"] = py::cpp_function([&]() -> int {
-            return 42;
-        });
+        local["call_test"] = py::cpp_function([&]() -> int { return 42; });
 
         auto result = py::eval<py::eval_single_statement>("x = call_test()", py::dict(), local);
         auto x = local["x"].cast<int>();
@@ -113,7 +109,9 @@ TEST_SUBMODULE(eval_, m) {
 
             def func_local():
                 return local_value
-            )", global, local);
+            )",
+                 global,
+                 local);
         return std::make_pair(global, local);
     });
 }
diff --git a/tests/test_exceptions.cpp b/tests/test_exceptions.cpp
index 3aa9673828..b47ae33bad 100644
--- a/tests/test_exceptions.cpp
+++ b/tests/test_exceptions.cpp
@@ -9,8 +9,8 @@
 #include "test_exceptions.h"
 
 #include "local_bindings.h"
-
 #include "pybind11_tests.h"
+
 #include <exception>
 #include <stdexcept>
 #include <utility>
@@ -18,8 +18,9 @@
 // A type that should be raised as an exception in Python
 class MyException : public std::exception {
 public:
-    explicit MyException(const char * m) : message{m} {}
-    const char * what() const noexcept override {return message.c_str();}
+    explicit MyException(const char *m) : message{m} {}
+    const char *what() const noexcept override { return message.c_str(); }
+
 private:
     std::string message = "";
 };
@@ -27,8 +28,9 @@ class MyException : public std::exception {
 // A type that should be translated to a standard Python exception
 class MyException2 : public std::exception {
 public:
-    explicit MyException2(const char * m) : message{m} {}
-    const char * what() const noexcept override {return message.c_str();}
+    explicit MyException2(const char *m) : message{m} {}
+    const char *what() const noexcept override { return message.c_str(); }
+
 private:
     std::string message = "";
 };
@@ -36,13 +38,13 @@ class MyException2 : public std::exception {
 // A type that is not derived from std::exception (and is thus unknown)
 class MyException3 {
 public:
-    explicit MyException3(const char * m) : message{m} {}
-    virtual const char * what() const noexcept {return message.c_str();}
+    explicit MyException3(const char *m) : message{m} {}
+    virtual const char *what() const noexcept { return message.c_str(); }
     // Rule of 5 BEGIN: to preempt compiler warnings.
-    MyException3(const MyException3&) = default;
-    MyException3(MyException3&&) = default;
-    MyException3& operator=(const MyException3&) = default;
-    MyException3& operator=(MyException3&&) = default;
+    MyException3(const MyException3 &) = default;
+    MyException3(MyException3 &&) = default;
+    MyException3 &operator=(const MyException3 &) = default;
+    MyException3 &operator=(MyException3 &&) = default;
     virtual ~MyException3() = default;
     // Rule of 5 END.
 private:
@@ -53,13 +55,13 @@ class MyException3 {
 // and delegated to its exception translator
 class MyException4 : public std::exception {
 public:
-    explicit MyException4(const char * m) : message{m} {}
-    const char * what() const noexcept override {return message.c_str();}
+    explicit MyException4(const char *m) : message{m} {}
+    const char *what() const noexcept override { return message.c_str(); }
+
 private:
     std::string message = "";
 };
 
-
 // Like the above, but declared via the helper function
 class MyException5 : public std::logic_error {
 public:
@@ -71,17 +73,16 @@ class MyException5_1 : public MyException5 {
     using MyException5::MyException5;
 };
 
-
 // Exception that will be caught via the module local translator.
 class MyException6 : public std::exception {
 public:
-    explicit MyException6(const char * m) : message{m} {}
-    const char * what() const noexcept override {return message.c_str();}
+    explicit MyException6(const char *m) : message{m} {}
+    const char *what() const noexcept override { return message.c_str(); }
+
 private:
     std::string message = "";
 };
 
-
 struct PythonCallInDestructor {
     explicit PythonCallInDestructor(const py::dict &d) : d(d) {}
     ~PythonCallInDestructor() { d["good"] = true; }
@@ -89,8 +90,6 @@ struct PythonCallInDestructor {
     py::dict d;
 };
 
-
-
 struct PythonAlreadySetInDestructor {
     explicit PythonAlreadySetInDestructor(const py::str &s) : s(s) {}
     ~PythonAlreadySetInDestructor() {
@@ -98,8 +97,7 @@ struct PythonAlreadySetInDestructor {
         try {
             // Assign to a py::object to force read access of nonexistent dict entry
             py::object o = foo["bar"];
-        }
-        catch (py::error_already_set& ex) {
+        } catch (py::error_already_set &ex) {
             ex.discard_as_unraisable(s);
         }
     }
@@ -108,15 +106,15 @@ struct PythonAlreadySetInDestructor {
 };
 
 TEST_SUBMODULE(exceptions, m) {
-    m.def("throw_std_exception", []() {
-        throw std::runtime_error("This exception was intentionally thrown.");
-    });
+    m.def("throw_std_exception",
+          []() { throw std::runtime_error("This exception was intentionally thrown."); });
 
     // make a new custom exception and use it as a translation target
     static py::exception<MyException> ex(m, "MyException");
     py::register_exception_translator([](std::exception_ptr p) {
         try {
-            if (p) std::rethrow_exception(p);
+            if (p)
+                std::rethrow_exception(p);
         } catch (const MyException &e) {
             // Set MyException as the active python error
             ex(e.what());
@@ -128,7 +126,8 @@ TEST_SUBMODULE(exceptions, m) {
     // never by visible from Python
     py::register_exception_translator([](std::exception_ptr p) {
         try {
-            if (p) std::rethrow_exception(p);
+            if (p)
+                std::rethrow_exception(p);
         } catch (const MyException2 &e) {
             // Translate this exception to a standard RuntimeError
             PyErr_SetString(PyExc_RuntimeError, e.what());
@@ -140,7 +139,8 @@ TEST_SUBMODULE(exceptions, m) {
     // translator for MyException by throwing a new exception
     py::register_exception_translator([](std::exception_ptr p) {
         try {
-            if (p) std::rethrow_exception(p);
+            if (p)
+                std::rethrow_exception(p);
         } catch (const MyException4 &e) {
             throw MyException(e.what());
         }
@@ -151,26 +151,30 @@ TEST_SUBMODULE(exceptions, m) {
     // A slightly more complicated one that declares MyException5_1 as a subclass of MyException5
     py::register_exception<MyException5_1>(m, "MyException5_1", ex5.ptr());
 
-    //py::register_local_exception<LocalSimpleException>(m, "LocalSimpleException")
+    // py::register_local_exception<LocalSimpleException>(m, "LocalSimpleException")
 
     py::register_local_exception_translator([](std::exception_ptr p) {
-      try {
-          if (p) {
-            std::rethrow_exception(p);
-          }
-      } catch (const MyException6 &e) {
-        PyErr_SetString(PyExc_RuntimeError, e.what());
-      }
+        try {
+            if (p) {
+                std::rethrow_exception(p);
+            }
+        } catch (const MyException6 &e) {
+            PyErr_SetString(PyExc_RuntimeError, e.what());
+        }
     });
 
     m.def("throws1", []() { throw MyException("this error should go to a custom type"); });
-    m.def("throws2", []() { throw MyException2("this error should go to a standard Python exception"); });
+    m.def("throws2",
+          []() { throw MyException2("this error should go to a standard Python exception"); });
     m.def("throws3", []() { throw MyException3("this error cannot be translated"); });
     m.def("throws4", []() { throw MyException4("this error is rethrown"); });
-    m.def("throws5", []() { throw MyException5("this is a helper-defined translated exception"); });
+    m.def("throws5",
+          []() { throw MyException5("this is a helper-defined translated exception"); });
     m.def("throws5_1", []() { throw MyException5_1("MyException5 subclass"); });
     m.def("throws6", []() { throw MyException6("MyException6 only handled in this module"); });
-    m.def("throws_logic_error", []() { throw std::logic_error("this error should fall through to the standard handler"); });
+    m.def("throws_logic_error", []() {
+        throw std::logic_error("this error should fall through to the standard handler");
+    });
     m.def("throws_overflow_error", []() { throw std::overflow_error(""); });
     m.def("throws_local_error", []() { throw LocalException("never caught"); });
     m.def("throws_local_simple_error", []() { throw LocalSimpleException("this mod"); });
@@ -179,9 +183,9 @@ TEST_SUBMODULE(exceptions, m) {
         try {
             // Assign to a py::object to force read access of nonexistent dict entry
             py::object o = foo["bar"];
-        }
-        catch (py::error_already_set& ex) {
-            if (!ex.matches(PyExc_KeyError)) throw;
+        } catch (py::error_already_set &ex) {
+            if (!ex.matches(PyExc_KeyError))
+                throw;
             return true;
         }
         return false;
@@ -191,9 +195,9 @@ TEST_SUBMODULE(exceptions, m) {
         try {
             // Assign to a py::object to force read access of nonexistent dict entry
             py::object o = foo["bar"];
-        }
-        catch (py::error_already_set &ex) {
-            if (!ex.matches(PyExc_Exception)) throw;
+        } catch (py::error_already_set &ex) {
+            if (!ex.matches(PyExc_Exception))
+                throw;
             return true;
         }
         return false;
@@ -202,9 +206,9 @@ TEST_SUBMODULE(exceptions, m) {
         try {
             // On Python >= 3.6, this raises a ModuleNotFoundError, a subclass of ImportError
             py::module_::import("nonexistent");
-        }
-        catch (py::error_already_set &ex) {
-            if (!ex.matches(PyExc_ImportError)) throw;
+        } catch (py::error_already_set &ex) {
+            if (!ex.matches(PyExc_ImportError))
+                throw;
             return true;
         }
         return false;
@@ -215,10 +219,9 @@ TEST_SUBMODULE(exceptions, m) {
             PyErr_SetString(PyExc_ValueError, "foo");
         try {
             throw py::error_already_set();
-        } catch (const std::runtime_error& e) {
-            if ((err && e.what() != std::string("ValueError: foo")) ||
-                (!err && e.what() != std::string("Unknown internal error occurred")))
-            {
+        } catch (const std::runtime_error &e) {
+            if ((err && e.what() != std::string("ValueError: foo"))
+                || (!err && e.what() != std::string("Unknown internal error occurred"))) {
                 PyErr_Clear();
                 throw std::runtime_error("error message mismatch");
             }
@@ -235,7 +238,7 @@ TEST_SUBMODULE(exceptions, m) {
             PythonCallInDestructor set_dict_in_destructor(d);
             PyErr_SetString(PyExc_ValueError, "foo");
             throw py::error_already_set();
-        } catch (const py::error_already_set&) {
+        } catch (const py::error_already_set &) {
             retval = true;
         }
         return retval;
@@ -260,7 +263,7 @@ TEST_SUBMODULE(exceptions, m) {
           });
 
     // Test repr that cannot be displayed
-    m.def("simple_bool_passthrough", [](bool x) {return x;});
+    m.def("simple_bool_passthrough", [](bool x) { return x; });
 
     m.def("throw_should_be_translated_to_key_error", []() { throw shared_exception(); });
 
@@ -276,7 +279,7 @@ TEST_SUBMODULE(exceptions, m) {
         try {
             PyErr_SetString(PyExc_ValueError, "inner");
             throw py::error_already_set();
-        } catch (py::error_already_set& e) {
+        } catch (py::error_already_set &e) {
             py::raise_from(e, PyExc_ValueError, "outer");
             throw py::error_already_set();
         }
diff --git a/tests/test_exceptions.h b/tests/test_exceptions.h
index 9d428312eb..03684b89fa 100644
--- a/tests/test_exceptions.h
+++ b/tests/test_exceptions.h
@@ -1,5 +1,6 @@
 #pragma once
 #include "pybind11_tests.h"
+
 #include <stdexcept>
 
 // shared exceptions for cross_module_tests
diff --git a/tests/test_factory_constructors.cpp b/tests/test_factory_constructors.cpp
index 660e2896af..f7568a7b0b 100644
--- a/tests/test_factory_constructors.cpp
+++ b/tests/test_factory_constructors.cpp
@@ -10,6 +10,7 @@
 
 #include "constructor_stats.h"
 #include "pybind11_tests.h"
+
 #include <cmath>
 #include <new>
 #include <utility>
@@ -89,6 +90,7 @@ class TestFactory6 {
 protected:
     int value;
     bool alias = false;
+
 public:
     explicit TestFactory6(int i) : value{i} { print_created(this, i); }
     TestFactory6(TestFactory6 &&f) noexcept {
@@ -96,7 +98,11 @@ class TestFactory6 {
         value = f.value;
         alias = f.alias;
     }
-    TestFactory6(const TestFactory6 &f) { print_copy_created(this); value = f.value; alias = f.alias; }
+    TestFactory6(const TestFactory6 &f) {
+        print_copy_created(this);
+        value = f.value;
+        alias = f.alias;
+    }
     virtual ~TestFactory6() { print_destroyed(this); }
     virtual int get() { return value; }
     bool has_alias() const { return alias; }
@@ -127,6 +133,7 @@ class TestFactory7 {
 protected:
     int value;
     bool alias = false;
+
 public:
     explicit TestFactory7(int i) : value{i} { print_created(this, i); }
     TestFactory7(TestFactory7 &&f) noexcept {
@@ -134,7 +141,11 @@ class TestFactory7 {
         value = f.value;
         alias = f.alias;
     }
-    TestFactory7(const TestFactory7 &f) { print_copy_created(this); value = f.value; alias = f.alias; }
+    TestFactory7(const TestFactory7 &f) {
+        print_copy_created(this);
+        value = f.value;
+        alias = f.alias;
+    }
     virtual ~TestFactory7() { print_destroyed(this); }
     virtual int get() { return value; }
     bool has_alias() const { return alias; }
@@ -151,14 +162,15 @@ class PyTF7 : public TestFactory7 {
     int get() override { PYBIND11_OVERRIDE(int, TestFactory7, get, /*no args*/); }
 };
 
-
 class TestFactoryHelper {
 public:
     // Non-movable, non-copyable type:
     // Return via pointer:
     static TestFactory1 *construct1() { return new TestFactory1(); }
     // Holder:
-    static std::unique_ptr<TestFactory1> construct1(int a) { return std::unique_ptr<TestFactory1>(new TestFactory1(a)); }
+    static std::unique_ptr<TestFactory1> construct1(int a) {
+        return std::unique_ptr<TestFactory1>(new TestFactory1(a));
+    }
     // pointer again
     static TestFactory1 *construct1_string(std::string a) {
         return new TestFactory1(std::move(a));
@@ -168,7 +180,9 @@ class TestFactoryHelper {
     // pointer:
     static TestFactory2 *construct2() { return new TestFactory2(); }
     // holder:
-    static std::unique_ptr<TestFactory2> construct2(int a) { return std::unique_ptr<TestFactory2>(new TestFactory2(a)); }
+    static std::unique_ptr<TestFactory2> construct2(int a) {
+        return std::unique_ptr<TestFactory2>(new TestFactory2(a));
+    }
     // by value moving:
     static TestFactory2 construct2(std::string a) { return TestFactory2(std::move(a)); }
 
@@ -176,16 +190,18 @@ class TestFactoryHelper {
     // pointer:
     static TestFactory3 *construct3() { return new TestFactory3(); }
     // holder:
-    static std::shared_ptr<TestFactory3> construct3(int a) { return std::shared_ptr<TestFactory3>(new TestFactory3(a)); }
+    static std::shared_ptr<TestFactory3> construct3(int a) {
+        return std::shared_ptr<TestFactory3>(new TestFactory3(a));
+    }
 };
 
 TEST_SUBMODULE(factory_constructors, m) {
 
     // Define various trivial types to allow simpler overload resolution:
     py::module_ m_tag = m.def_submodule("tag");
-#define MAKE_TAG_TYPE(Name) \
-    struct Name##_tag {}; \
-    py::class_<Name##_tag>(m_tag, #Name "_tag").def(py::init<>()); \
+#define MAKE_TAG_TYPE(Name)                                                                       \
+    struct Name##_tag {};                                                                         \
+    py::class_<Name##_tag>(m_tag, #Name "_tag").def(py::init<>());                                \
     m_tag.attr(#Name) = py::cast(Name##_tag{})
     MAKE_TAG_TYPE(pointer);
     MAKE_TAG_TYPE(unique_ptr);
@@ -208,9 +224,9 @@ TEST_SUBMODULE(factory_constructors, m) {
         .def(py::init([](unique_ptr_tag, int v) { return TestFactoryHelper::construct1(v); }))
         .def(py::init(&TestFactoryHelper::construct1_string)) // raw function pointer
         .def(py::init([](pointer_tag) { return TestFactoryHelper::construct1(); }))
-        .def(py::init([](py::handle, int v, py::handle) { return TestFactoryHelper::construct1(v); }))
-        .def_readwrite("value", &TestFactory1::value)
-        ;
+        .def(py::init(
+            [](py::handle, int v, py::handle) { return TestFactoryHelper::construct1(v); }))
+        .def_readwrite("value", &TestFactory1::value);
     py::class_<TestFactory2>(m, "TestFactory2")
         .def(py::init([](pointer_tag, int v) { return TestFactoryHelper::construct2(v); }))
         .def(py::init([](unique_ptr_tag, std::string v) {
@@ -221,7 +237,10 @@ TEST_SUBMODULE(factory_constructors, m) {
 
     // Stateful & reused:
     int c = 1;
-    auto c4a = [c](pointer_tag, TF4_tag, int a) { (void) c; return new TestFactory4(a);};
+    auto c4a = [c](pointer_tag, TF4_tag, int a) {
+        (void) c;
+        return new TestFactory4(a);
+    };
 
     // test_init_factory_basic, test_init_factory_casting
     py::class_<TestFactory3, std::shared_ptr<TestFactory3>> pyTestFactory3(m, "TestFactory3");
@@ -238,16 +257,17 @@ TEST_SUBMODULE(factory_constructors, m) {
         .def(py::init(c4a)) // derived ptr
         .def(py::init([](pointer_tag, TF5_tag, int a) { return new TestFactory5(a); }))
         // derived shared ptr:
-        .def(py::init([](shared_ptr_tag, TF4_tag, int a) { return std::make_shared<TestFactory4>(a); }))
-        .def(py::init([](shared_ptr_tag, TF5_tag, int a) { return std::make_shared<TestFactory5>(a); }))
+        .def(py::init(
+            [](shared_ptr_tag, TF4_tag, int a) { return std::make_shared<TestFactory4>(a); }))
+        .def(py::init(
+            [](shared_ptr_tag, TF5_tag, int a) { return std::make_shared<TestFactory5>(a); }))
 
         // Returns nullptr:
         .def(py::init([](null_ptr_tag) { return (TestFactory3 *) nullptr; }))
         .def(py::init([](null_unique_ptr_tag) { return std::unique_ptr<TestFactory3>(); }))
         .def(py::init([](null_shared_ptr_tag) { return std::shared_ptr<TestFactory3>(); }))
 
-        .def_readwrite("value", &TestFactory3::value)
-        ;
+        .def_readwrite("value", &TestFactory3::value);
 
     // test_init_factory_casting
     py::class_<TestFactory4, TestFactory3, std::shared_ptr<TestFactory4>>(m, "TestFactory4")
@@ -331,9 +351,7 @@ TEST_SUBMODULE(factory_constructors, m) {
     py::class_<NoPlacementNew>(m, "NoPlacementNew")
         .def(py::init<int>())
         .def(py::init([]() { return new NoPlacementNew(100); }))
-        .def_readwrite("i", &NoPlacementNew::i)
-        ;
-
+        .def_readwrite("i", &NoPlacementNew::i);
 
     // test_reallocations
     // Class that has verbose operator_new/operator_delete calls
@@ -343,23 +361,36 @@ TEST_SUBMODULE(factory_constructors, m) {
         explicit NoisyAlloc(double d) { py::print(py::str("NoisyAlloc(double {})").format(d)); }
         ~NoisyAlloc() { py::print("~NoisyAlloc()"); }
 
-        static void *operator new(size_t s) { py::print("noisy new"); return ::operator new(s); }
-        static void *operator new(size_t, void *p) { py::print("noisy placement new"); return p; }
-        static void operator delete(void *p, size_t) { py::print("noisy delete"); ::operator delete(p); }
+        static void *operator new(size_t s) {
+            py::print("noisy new");
+            return ::operator new(s);
+        }
+        static void *operator new(size_t, void *p) {
+            py::print("noisy placement new");
+            return p;
+        }
+        static void operator delete(void *p, size_t) {
+            py::print("noisy delete");
+            ::operator delete(p);
+        }
         static void operator delete(void *, void *) { py::print("noisy placement delete"); }
 #if defined(_MSC_VER) && _MSC_VER < 1910
         // MSVC 2015 bug: the above "noisy delete" isn't invoked (fixed in MSVC 2017)
-        static void operator delete(void *p) { py::print("noisy delete"); ::operator delete(p); }
+        static void operator delete(void *p) {
+            py::print("noisy delete");
+            ::operator delete(p);
+        }
 #endif
     };
 
-
     py::class_<NoisyAlloc> pyNoisyAlloc(m, "NoisyAlloc");
-        // Since these overloads have the same number of arguments, the dispatcher will try each of
-        // them until the arguments convert.  Thus we can get a pre-allocation here when passing a
-        // single non-integer:
+    // Since these overloads have the same number of arguments, the dispatcher will try each of
+    // them until the arguments convert.  Thus we can get a pre-allocation here when passing a
+    // single non-integer:
     ignoreOldStyleInitWarnings([&pyNoisyAlloc]() {
-        pyNoisyAlloc.def("__init__", [](NoisyAlloc *a, int i) { new (a) NoisyAlloc(i); }); // Regular constructor, runs first, requires preallocation
+        pyNoisyAlloc.def("__init__", [](NoisyAlloc *a, int i) {
+            new (a) NoisyAlloc(i);
+        }); // Regular constructor, runs first, requires preallocation
     });
 
     pyNoisyAlloc.def(py::init([](double d) { return new NoisyAlloc(d); }));
@@ -370,7 +401,8 @@ TEST_SUBMODULE(factory_constructors, m) {
     pyNoisyAlloc.def(py::init([](double d, int) { return NoisyAlloc(d); }));
     // Old-style placement new init; requires preallocation
     ignoreOldStyleInitWarnings([&pyNoisyAlloc]() {
-        pyNoisyAlloc.def("__init__", [](NoisyAlloc &a, double d, double) { new (&a) NoisyAlloc(d); });
+        pyNoisyAlloc.def("__init__",
+                         [](NoisyAlloc &a, double d, double) { new (&a) NoisyAlloc(d); });
     });
     // Requires deallocation of previous overload preallocated value:
     pyNoisyAlloc.def(py::init([](int i, double) { return new NoisyAlloc(i); }));
@@ -380,7 +412,8 @@ TEST_SUBMODULE(factory_constructors, m) {
             "__init__", [](NoisyAlloc &a, int i, const std::string &) { new (&a) NoisyAlloc(i); });
     });
 
-    // static_assert testing (the following def's should all fail with appropriate compilation errors):
+    // static_assert testing (the following def's should all fail with appropriate compilation
+    // errors):
 #if 0
     struct BadF1Base {};
     struct BadF1 : BadF1Base {};
diff --git a/tests/test_gil_scoped.cpp b/tests/test_gil_scoped.cpp
index b261085c88..97efdc1616 100644
--- a/tests/test_gil_scoped.cpp
+++ b/tests/test_gil_scoped.cpp
@@ -7,43 +7,41 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include <pybind11/functional.h>
 
+#include "pybind11_tests.h"
 
-class VirtClass  {
+class VirtClass {
 public:
     virtual ~VirtClass() = default;
     VirtClass() = default;
-    VirtClass(const VirtClass&) = delete;
+    VirtClass(const VirtClass &) = delete;
     virtual void virtual_func() {}
     virtual void pure_virtual_func() = 0;
 };
 
 class PyVirtClass : public VirtClass {
-    void virtual_func() override {
-        PYBIND11_OVERRIDE(void, VirtClass, virtual_func,);
-    }
+    void virtual_func() override { PYBIND11_OVERRIDE(void, VirtClass, virtual_func, ); }
     void pure_virtual_func() override {
-        PYBIND11_OVERRIDE_PURE(void, VirtClass, pure_virtual_func,);
+        PYBIND11_OVERRIDE_PURE(void, VirtClass, pure_virtual_func, );
     }
 };
 
 TEST_SUBMODULE(gil_scoped, m) {
-  py::class_<VirtClass, PyVirtClass>(m, "VirtClass")
-      .def(py::init<>())
-      .def("virtual_func", &VirtClass::virtual_func)
-      .def("pure_virtual_func", &VirtClass::pure_virtual_func);
-
-  m.def("test_callback_py_obj", [](py::object &func) { func(); });
-  m.def("test_callback_std_func", [](const std::function<void()> &func) { func(); });
-  m.def("test_callback_virtual_func", [](VirtClass &virt) { virt.virtual_func(); });
-  m.def("test_callback_pure_virtual_func", [](VirtClass &virt) { virt.pure_virtual_func(); });
-  m.def("test_cross_module_gil", []() {
-      auto cm = py::module_::import("cross_module_gil_utils");
-      auto gil_acquire
-          = reinterpret_cast<void (*)()>(PyLong_AsVoidPtr(cm.attr("gil_acquire_funcaddr").ptr()));
-      py::gil_scoped_release gil_release;
-      gil_acquire();
-  });
+    py::class_<VirtClass, PyVirtClass>(m, "VirtClass")
+        .def(py::init<>())
+        .def("virtual_func", &VirtClass::virtual_func)
+        .def("pure_virtual_func", &VirtClass::pure_virtual_func);
+
+    m.def("test_callback_py_obj", [](py::object &func) { func(); });
+    m.def("test_callback_std_func", [](const std::function<void()> &func) { func(); });
+    m.def("test_callback_virtual_func", [](VirtClass &virt) { virt.virtual_func(); });
+    m.def("test_callback_pure_virtual_func", [](VirtClass &virt) { virt.pure_virtual_func(); });
+    m.def("test_cross_module_gil", []() {
+        auto cm = py::module_::import("cross_module_gil_utils");
+        auto gil_acquire = reinterpret_cast<void (*)()>(
+            PyLong_AsVoidPtr(cm.attr("gil_acquire_funcaddr").ptr()));
+        py::gil_scoped_release gil_release;
+        gil_acquire();
+    });
 }
diff --git a/tests/test_iostream.cpp b/tests/test_iostream.cpp
index c620b59493..22063dfa15 100644
--- a/tests/test_iostream.cpp
+++ b/tests/test_iostream.cpp
@@ -7,12 +7,14 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#if defined(_MSC_VER) && _MSC_VER < 1910  // VS 2015's MSVC
-#  pragma warning(disable: 4702) // unreachable code in system header (xatomic.h(382))
+#if defined(_MSC_VER) && _MSC_VER < 1910 // VS 2015's MSVC
+#    pragma warning(disable : 4702)      // unreachable code in system header (xatomic.h(382))
 #endif
 
 #include <pybind11/iostream.h>
+
 #include "pybind11_tests.h"
+
 #include <atomic>
 #include <iostream>
 #include <mutex>
@@ -50,13 +52,12 @@ struct TestThread {
                     std::cout << "x" << std::flush;
                 }
                 std::this_thread::sleep_for(std::chrono::microseconds(50));
-            } };
+            }
+        };
         t_ = new std::thread(std::move(thread_f));
     }
 
-    ~TestThread() {
-        delete t_;
-    }
+    ~TestThread() { delete t_; }
 
     void stop() { stop_ = true; }
 
@@ -74,7 +75,6 @@ struct TestThread {
     std::atomic<bool> stop_;
 };
 
-
 TEST_SUBMODULE(iostream, m) {
 
     add_ostream_redirect(m);
@@ -91,9 +91,11 @@ TEST_SUBMODULE(iostream, m) {
         std::cout << msg << std::flush;
     });
 
-    m.def("guard_output", &noisy_function,
-            py::call_guard<py::scoped_ostream_redirect>(),
-            py::arg("msg"), py::arg("flush")=true);
+    m.def("guard_output",
+          &noisy_function,
+          py::call_guard<py::scoped_ostream_redirect>(),
+          py::arg("msg"),
+          py::arg("flush") = true);
 
     m.def("captured_err", [](const std::string &msg) {
         py::scoped_ostream_redirect redir(std::cerr, py::module_::import("sys").attr("stderr"));
@@ -102,9 +104,11 @@ TEST_SUBMODULE(iostream, m) {
 
     m.def("noisy_function", &noisy_function, py::arg("msg"), py::arg("flush") = true);
 
-    m.def("dual_guard", &noisy_funct_dual,
-            py::call_guard<py::scoped_ostream_redirect, py::scoped_estream_redirect>(),
-            py::arg("msg"), py::arg("emsg"));
+    m.def("dual_guard",
+          &noisy_funct_dual,
+          py::call_guard<py::scoped_ostream_redirect, py::scoped_estream_redirect>(),
+          py::arg("msg"),
+          py::arg("emsg"));
 
     m.def("raw_output", [](const std::string &msg) { std::cout << msg << std::flush; });
 
diff --git a/tests/test_kwargs_and_defaults.cpp b/tests/test_kwargs_and_defaults.cpp
index 34ad2a8647..293d2f25ce 100644
--- a/tests/test_kwargs_and_defaults.cpp
+++ b/tests/test_kwargs_and_defaults.cpp
@@ -7,38 +7,42 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
-#include "constructor_stats.h"
 #include <pybind11/stl.h>
 
+#include "constructor_stats.h"
+#include "pybind11_tests.h"
+
 #include <utility>
 
 TEST_SUBMODULE(kwargs_and_defaults, m) {
-    auto kw_func = [](int x, int y) { return "x=" + std::to_string(x) + ", y=" + std::to_string(y); };
+    auto kw_func
+        = [](int x, int y) { return "x=" + std::to_string(x) + ", y=" + std::to_string(y); };
 
     // test_named_arguments
     m.def("kw_func0", kw_func);
     m.def("kw_func1", kw_func, py::arg("x"), py::arg("y"));
     m.def("kw_func2", kw_func, py::arg("x") = 100, py::arg("y") = 200);
-    m.def("kw_func3", [](const char *) { }, py::arg("data") = std::string("Hello world!"));
+    m.def(
+        "kw_func3", [](const char *) {}, py::arg("data") = std::string("Hello world!"));
 
     /* A fancier default argument */
     std::vector<int> list{{13, 17}};
-    m.def("kw_func4", [](const std::vector<int> &entries) {
-        std::string ret = "{";
-        for (int i : entries)
-            ret += std::to_string(i) + " ";
-        ret.back() = '}';
-        return ret;
-    }, py::arg("myList") = list);
+    m.def(
+        "kw_func4",
+        [](const std::vector<int> &entries) {
+            std::string ret = "{";
+            for (int i : entries)
+                ret += std::to_string(i) + " ";
+            ret.back() = '}';
+            return ret;
+        },
+        py::arg("myList") = list);
 
-    m.def("kw_func_udl", kw_func, "x"_a, "y"_a=300);
-    m.def("kw_func_udl_z", kw_func, "x"_a, "y"_a=0);
+    m.def("kw_func_udl", kw_func, "x"_a, "y"_a = 300);
+    m.def("kw_func_udl_z", kw_func, "x"_a, "y"_a = 0);
 
     // test_args_and_kwargs
-    m.def("args_function", [](py::args args) -> py::tuple {
-        return std::move(args);
-    });
+    m.def("args_function", [](py::args args) -> py::tuple { return std::move(args); });
     m.def("args_kwargs_function", [](const py::args &args, const py::kwargs &kwargs) {
         return py::make_tuple(args, kwargs);
     });
@@ -53,35 +57,60 @@ TEST_SUBMODULE(kwargs_and_defaults, m) {
     };
     m.def("mixed_plus_args_kwargs", mixed_plus_both);
 
-    m.def("mixed_plus_args_kwargs_defaults", mixed_plus_both,
-            py::arg("i") = 1, py::arg("j") = 3.14159);
-
-    m.def("args_kwonly",
-            [](int i, double j, const py::args &args, int z) { return py::make_tuple(i, j, args, z); },
-            "i"_a, "j"_a, "z"_a);
-    m.def("args_kwonly_kwargs",
-            [](int i, double j, const py::args &args, int z, const py::kwargs &kwargs) {
-                return py::make_tuple(i, j, args, z, kwargs); },
-            "i"_a, "j"_a, py::kw_only{}, "z"_a);
-    m.def("args_kwonly_kwargs_defaults",
-            [](int i, double j, const py::args &args, int z, const py::kwargs &kwargs) {
-                return py::make_tuple(i, j, args, z, kwargs); },
-            "i"_a = 1, "j"_a = 3.14159, "z"_a = 42);
-    m.def("args_kwonly_full_monty",
-            [](int h, int i, double j, const py::args &args, int z, const py::kwargs &kwargs) {
-                return py::make_tuple(h, i, j, args, z, kwargs); },
-            py::arg() = 1, py::arg() = 2, py::pos_only{}, "j"_a = 3.14159, "z"_a = 42);
-
-
-    // test_args_refcount
-    // PyPy needs a garbage collection to get the reference count values to match CPython's behaviour
-    #ifdef PYPY_VERSION
-    #define GC_IF_NEEDED ConstructorStats::gc()
-    #else
-    #define GC_IF_NEEDED
-    #endif
-    m.def("arg_refcount_h", [](py::handle h) { GC_IF_NEEDED; return h.ref_count(); });
-    m.def("arg_refcount_h", [](py::handle h, py::handle, py::handle) { GC_IF_NEEDED; return h.ref_count(); });
+    m.def("mixed_plus_args_kwargs_defaults",
+          mixed_plus_both,
+          py::arg("i") = 1,
+          py::arg("j") = 3.14159);
+
+    m.def(
+        "args_kwonly",
+        [](int i, double j, const py::args &args, int z) { return py::make_tuple(i, j, args, z); },
+        "i"_a,
+        "j"_a,
+        "z"_a);
+    m.def(
+        "args_kwonly_kwargs",
+        [](int i, double j, const py::args &args, int z, const py::kwargs &kwargs) {
+            return py::make_tuple(i, j, args, z, kwargs);
+        },
+        "i"_a,
+        "j"_a,
+        py::kw_only{},
+        "z"_a);
+    m.def(
+        "args_kwonly_kwargs_defaults",
+        [](int i, double j, const py::args &args, int z, const py::kwargs &kwargs) {
+            return py::make_tuple(i, j, args, z, kwargs);
+        },
+        "i"_a = 1,
+        "j"_a = 3.14159,
+        "z"_a = 42);
+    m.def(
+        "args_kwonly_full_monty",
+        [](int h, int i, double j, const py::args &args, int z, const py::kwargs &kwargs) {
+            return py::make_tuple(h, i, j, args, z, kwargs);
+        },
+        py::arg() = 1,
+        py::arg() = 2,
+        py::pos_only{},
+        "j"_a = 3.14159,
+        "z"_a = 42);
+
+// test_args_refcount
+// PyPy needs a garbage collection to get the reference count values to match CPython's behaviour
+#ifdef PYPY_VERSION
+#    define GC_IF_NEEDED ConstructorStats::gc()
+#else
+#    define GC_IF_NEEDED
+#endif
+    m.def("arg_refcount_h", [](py::handle h) {
+        GC_IF_NEEDED;
+        return h.ref_count();
+    });
+    m.def("arg_refcount_h", [](py::handle h, py::handle, py::handle) {
+        GC_IF_NEEDED;
+        return h.ref_count();
+    });
     m.def("arg_refcount_o", [](const py::object &o) {
         GC_IF_NEEDED;
         return o.ref_count();
@@ -106,23 +135,42 @@ TEST_SUBMODULE(kwargs_and_defaults, m) {
 
     // pybind11 won't allow these to be bound: args and kwargs, if present, must be at the end.
     // Uncomment these to test that the static_assert is indeed working:
-//    m.def("bad_args1", [](py::args, int) {});
-//    m.def("bad_args2", [](py::kwargs, int) {});
-//    m.def("bad_args3", [](py::kwargs, py::args) {});
-//    m.def("bad_args4", [](py::args, int, py::kwargs) {});
-//    m.def("bad_args5", [](py::args, py::kwargs, int) {});
-//    m.def("bad_args6", [](py::args, py::args) {});
-//    m.def("bad_args7", [](py::kwargs, py::kwargs) {});
+    //    m.def("bad_args1", [](py::args, int) {});
+    //    m.def("bad_args2", [](py::kwargs, int) {});
+    //    m.def("bad_args3", [](py::kwargs, py::args) {});
+    //    m.def("bad_args4", [](py::args, int, py::kwargs) {});
+    //    m.def("bad_args5", [](py::args, py::kwargs, int) {});
+    //    m.def("bad_args6", [](py::args, py::args) {});
+    //    m.def("bad_args7", [](py::kwargs, py::kwargs) {});
 
     // test_keyword_only_args
-    m.def("kw_only_all", [](int i, int j) { return py::make_tuple(i, j); },
-            py::kw_only(), py::arg("i"), py::arg("j"));
-    m.def("kw_only_some", [](int i, int j, int k) { return py::make_tuple(i, j, k); },
-            py::arg(), py::kw_only(), py::arg("j"), py::arg("k"));
-    m.def("kw_only_with_defaults", [](int i, int j, int k, int z) { return py::make_tuple(i, j, k, z); },
-            py::arg() = 3, "j"_a = 4, py::kw_only(), "k"_a = 5, "z"_a);
-    m.def("kw_only_mixed", [](int i, int j) { return py::make_tuple(i, j); },
-            "i"_a, py::kw_only(), "j"_a);
+    m.def(
+        "kw_only_all",
+        [](int i, int j) { return py::make_tuple(i, j); },
+        py::kw_only(),
+        py::arg("i"),
+        py::arg("j"));
+    m.def(
+        "kw_only_some",
+        [](int i, int j, int k) { return py::make_tuple(i, j, k); },
+        py::arg(),
+        py::kw_only(),
+        py::arg("j"),
+        py::arg("k"));
+    m.def(
+        "kw_only_with_defaults",
+        [](int i, int j, int k, int z) { return py::make_tuple(i, j, k, z); },
+        py::arg() = 3,
+        "j"_a = 4,
+        py::kw_only(),
+        "k"_a = 5,
+        "z"_a);
+    m.def(
+        "kw_only_mixed",
+        [](int i, int j) { return py::make_tuple(i, j); },
+        "i"_a,
+        py::kw_only(),
+        "j"_a);
     m.def(
         "kw_only_plus_more",
         [](int i, int j, int k, const py::kwargs &kwargs) {
@@ -134,29 +182,53 @@ TEST_SUBMODULE(kwargs_and_defaults, m) {
         py::arg("k") /* kw-only */);
 
     m.def("register_invalid_kw_only", [](py::module_ m) {
-        m.def("bad_kw_only", [](int i, int j) { return py::make_tuple(i, j); },
-                py::kw_only(), py::arg() /* invalid unnamed argument */, "j"_a);
+        m.def(
+            "bad_kw_only",
+            [](int i, int j) { return py::make_tuple(i, j); },
+            py::kw_only(),
+            py::arg() /* invalid unnamed argument */,
+            "j"_a);
     });
 
     // test_positional_only_args
-    m.def("pos_only_all", [](int i, int j) { return py::make_tuple(i, j); },
-            py::arg("i"), py::arg("j"), py::pos_only());
-    m.def("pos_only_mix", [](int i, int j) { return py::make_tuple(i, j); },
-            py::arg("i"), py::pos_only(), py::arg("j"));
-    m.def("pos_kw_only_mix", [](int i, int j, int k) { return py::make_tuple(i, j, k); },
-            py::arg("i"), py::pos_only(), py::arg("j"), py::kw_only(), py::arg("k"));
-    m.def("pos_only_def_mix", [](int i, int j, int k) { return py::make_tuple(i, j, k); },
-            py::arg("i"), py::arg("j") = 2, py::pos_only(), py::arg("k") = 3);
-
+    m.def(
+        "pos_only_all",
+        [](int i, int j) { return py::make_tuple(i, j); },
+        py::arg("i"),
+        py::arg("j"),
+        py::pos_only());
+    m.def(
+        "pos_only_mix",
+        [](int i, int j) { return py::make_tuple(i, j); },
+        py::arg("i"),
+        py::pos_only(),
+        py::arg("j"));
+    m.def(
+        "pos_kw_only_mix",
+        [](int i, int j, int k) { return py::make_tuple(i, j, k); },
+        py::arg("i"),
+        py::pos_only(),
+        py::arg("j"),
+        py::kw_only(),
+        py::arg("k"));
+    m.def(
+        "pos_only_def_mix",
+        [](int i, int j, int k) { return py::make_tuple(i, j, k); },
+        py::arg("i"),
+        py::arg("j") = 2,
+        py::pos_only(),
+        py::arg("k") = 3);
 
     // These should fail to compile:
     // argument annotations are required when using kw_only
-//    m.def("bad_kw_only1", [](int) {}, py::kw_only());
+    //    m.def("bad_kw_only1", [](int) {}, py::kw_only());
     // can't specify both `py::kw_only` and a `py::args` argument
-//    m.def("bad_kw_only2", [](int i, py::args) {}, py::kw_only(), "i"_a);
+    //    m.def("bad_kw_only2", [](int i, py::args) {}, py::kw_only(), "i"_a);
 
     // test_function_signatures (along with most of the above)
-    struct KWClass { void foo(int, float) {} };
+    struct KWClass {
+        void foo(int, float) {}
+    };
     py::class_<KWClass>(m, "KWClass")
         .def("foo0", &KWClass::foo)
         .def("foo1", &KWClass::foo, "x"_a, "y"_a);
@@ -177,11 +249,18 @@ TEST_SUBMODULE(kwargs_and_defaults, m) {
         .def(py::init([](int) { return first_arg_kw_only(); }),
              py::kw_only(), // This being before any args was broken
              py::arg("i") = 0)
-        .def("method", [](first_arg_kw_only&, int, int) {},
-             py::kw_only(), // and likewise here
-             py::arg("i") = 1, py::arg("j") = 2)
+        .def(
+            "method",
+            [](first_arg_kw_only &, int, int) {},
+            py::kw_only(), // and likewise here
+            py::arg("i") = 1,
+            py::arg("j") = 2)
         // Closely related: pos_only marker didn't show up properly when it was before any other
         // arguments (although that is fairly useless in practice).
-        .def("pos_only", [](first_arg_kw_only&, int, int) {},
-                py::pos_only{}, py::arg("i"), py::arg("j"));
+        .def(
+            "pos_only",
+            [](first_arg_kw_only &, int, int) {},
+            py::pos_only{},
+            py::arg("i"),
+            py::arg("j"));
 }
diff --git a/tests/test_local_bindings.cpp b/tests/test_local_bindings.cpp
index a5808e2f2a..afa1e74189 100644
--- a/tests/test_local_bindings.cpp
+++ b/tests/test_local_bindings.cpp
@@ -8,12 +8,12 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
-#include "local_bindings.h"
-
 #include <pybind11/stl.h>
 #include <pybind11/stl_bind.h>
 
+#include "local_bindings.h"
+#include "pybind11_tests.h"
+
 #include <numeric>
 #include <utility>
 
@@ -24,9 +24,9 @@ TEST_SUBMODULE(local_bindings, m) {
 
     // test_local_bindings
     // Register a class with py::module_local:
-    bind_local<LocalType, -1>(m, "LocalType", py::module_local())
-        .def("get3", [](LocalType &t) { return t.i + 3; })
-        ;
+    bind_local<LocalType, -1>(m, "LocalType", py::module_local()).def("get3", [](LocalType &t) {
+        return t.i + 3;
+    });
 
     m.def("local_value", [](LocalType &l) { return l.i; });
 
@@ -35,20 +35,20 @@ TEST_SUBMODULE(local_bindings, m) {
     // one, in pybind11_cross_module_tests.cpp, is designed to fail):
     bind_local<NonLocalType, 0>(m, "NonLocalType")
         .def(py::init<int>())
-        .def("get", [](LocalType &i) { return i.i; })
-        ;
+        .def("get", [](LocalType &i) { return i.i; });
 
     // test_duplicate_local
-    // py::module_local declarations should be visible across compilation units that get linked together;
-    // this tries to register a duplicate local.  It depends on a definition in test_class.cpp and
-    // should raise a runtime error from the duplicate definition attempt.  If test_class isn't
-    // available it *also* throws a runtime error (with "test_class not enabled" as value).
+    // py::module_local declarations should be visible across compilation units that get linked
+    // together; this tries to register a duplicate local.  It depends on a definition in
+    // test_class.cpp and should raise a runtime error from the duplicate definition attempt.  If
+    // test_class isn't available it *also* throws a runtime error (with "test_class not enabled"
+    // as value).
     m.def("register_local_external", [m]() {
         auto main = py::module_::import("pybind11_tests");
         if (py::hasattr(main, "class_")) {
             bind_local<LocalExternal, 7>(m, "LocalExternal", py::module_local());
-        }
-        else throw std::runtime_error("test_class not enabled");
+        } else
+            throw std::runtime_error("test_class not enabled");
     });
 
     // test_stl_bind_local
@@ -78,12 +78,12 @@ TEST_SUBMODULE(local_bindings, m) {
     m.def("get_mixed_lg", [](int i) { return MixedLocalGlobal(i); });
 
     // test_internal_locals_differ
-    m.def("local_cpp_types_addr", []() { return (uintptr_t) &py::detail::get_local_internals().registered_types_cpp; });
+    m.def("local_cpp_types_addr",
+          []() { return (uintptr_t) &py::detail::get_local_internals().registered_types_cpp; });
 
     // test_stl_caster_vs_stl_bind
-    m.def("load_vector_via_caster", [](std::vector<int> v) {
-        return std::accumulate(v.begin(), v.end(), 0);
-    });
+    m.def("load_vector_via_caster",
+          [](std::vector<int> v) { return std::accumulate(v.begin(), v.end(), 0); });
 
     // test_cross_module_calls
     m.def("return_self", [](LocalVec *v) { return v; });
@@ -93,11 +93,9 @@ TEST_SUBMODULE(local_bindings, m) {
     public:
         explicit Cat(std::string name) : Pet(std::move(name)) {}
     };
-    py::class_<pets::Pet>(m, "Pet", py::module_local())
-        .def("get_name", &pets::Pet::name);
+    py::class_<pets::Pet>(m, "Pet", py::module_local()).def("get_name", &pets::Pet::name);
     // Binding for local extending class:
-    py::class_<Cat, pets::Pet>(m, "Cat")
-        .def(py::init<std::string>());
+    py::class_<Cat, pets::Pet>(m, "Cat").def(py::init<std::string>());
     m.def("pet_name", [](pets::Pet &p) { return p.name(); });
 
     py::class_<MixGL>(m, "MixGL").def(py::init<int>());
diff --git a/tests/test_methods_and_attributes.cpp b/tests/test_methods_and_attributes.cpp
index 9e55452dec..10515e26f9 100644
--- a/tests/test_methods_and_attributes.cpp
+++ b/tests/test_methods_and_attributes.cpp
@@ -8,8 +8,8 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include "constructor_stats.h"
+#include "pybind11_tests.h"
 
 #if !defined(PYBIND11_OVERLOAD_CAST)
 template <typename... Args>
@@ -27,7 +27,10 @@ class ExampleMandA {
 
     std::string toString() const { return "ExampleMandA[value=" + std::to_string(value) + "]"; }
 
-    void operator=(const ExampleMandA &e) { print_copy_assigned(this); value = e.value; }
+    void operator=(const ExampleMandA &e) {
+        print_copy_assigned(this);
+        value = e.value;
+    }
     void operator=(ExampleMandA &&e) noexcept {
         print_move_assigned(this);
         value = e.value;
@@ -40,37 +43,37 @@ class ExampleMandA {
     void add4(ExampleMandA *other) { value += other->value; }       // passing by pointer
     void add5(const ExampleMandA *other) { value += other->value; } // passing by const pointer
 
-    void add6(int other) { value += other; }                        // passing by value
-    void add7(int &other) { value += other; }                       // passing by reference
-    void add8(const int &other) { value += other; }                 // passing by const reference
+    void add6(int other) { value += other; }        // passing by value
+    void add7(int &other) { value += other; }       // passing by reference
+    void add8(const int &other) { value += other; } // passing by const reference
     // NOLINTNEXTLINE(readability-non-const-parameter) Deliberately non-const for testing
-    void add9(int *other) { value += *other; }                      // passing by pointer
-    void add10(const int *other) { value += *other; }               // passing by const pointer
-
-    void consume_str(std::string&&) {}
-
-    ExampleMandA self1() { return *this; }                          // return by value
-    ExampleMandA &self2() { return *this; }                         // return by reference
-    const ExampleMandA &self3() const { return *this; }             // return by const reference
-    ExampleMandA *self4() { return this; }                          // return by pointer
-    const ExampleMandA *self5() const { return this; }              // return by const pointer
-
-    int internal1() const { return value; }                         // return by value
-    int &internal2() { return value; }                              // return by reference
-    const int &internal3() const { return value; }                  // return by const reference
-    int *internal4() { return &value; }                             // return by pointer
-    const int *internal5() { return &value; }                       // return by const pointer
-
-    py::str overloaded()             { return "()"; }
-    py::str overloaded(int)          { return "(int)"; }
-    py::str overloaded(int, float)   { return "(int, float)"; }
-    py::str overloaded(float, int)   { return "(float, int)"; }
-    py::str overloaded(int, int)     { return "(int, int)"; }
+    void add9(int *other) { value += *other; }        // passing by pointer
+    void add10(const int *other) { value += *other; } // passing by const pointer
+
+    void consume_str(std::string &&) {}
+
+    ExampleMandA self1() { return *this; }              // return by value
+    ExampleMandA &self2() { return *this; }             // return by reference
+    const ExampleMandA &self3() const { return *this; } // return by const reference
+    ExampleMandA *self4() { return this; }              // return by pointer
+    const ExampleMandA *self5() const { return this; }  // return by const pointer
+
+    int internal1() const { return value; }        // return by value
+    int &internal2() { return value; }             // return by reference
+    const int &internal3() const { return value; } // return by const reference
+    int *internal4() { return &value; }            // return by pointer
+    const int *internal5() { return &value; }      // return by const pointer
+
+    py::str overloaded() { return "()"; }
+    py::str overloaded(int) { return "(int)"; }
+    py::str overloaded(int, float) { return "(int, float)"; }
+    py::str overloaded(float, int) { return "(float, int)"; }
+    py::str overloaded(int, int) { return "(int, int)"; }
     py::str overloaded(float, float) { return "(float, float)"; }
-    py::str overloaded(int)          const { return "(int) const"; }
-    py::str overloaded(int, float)   const { return "(int, float) const"; }
-    py::str overloaded(float, int)   const { return "(float, int) const"; }
-    py::str overloaded(int, int)     const { return "(int, int) const"; }
+    py::str overloaded(int) const { return "(int) const"; }
+    py::str overloaded(int, float) const { return "(int, float) const"; }
+    py::str overloaded(float, int) const { return "(float, int) const"; }
+    py::str overloaded(int, int) const { return "(int, int) const"; }
     py::str overloaded(float, float) const { return "(float, float) const"; }
 
     static py::str overloaded(float) { return "static float"; }
@@ -112,7 +115,10 @@ UserType TestPropRVP::sv1(1);
 UserType TestPropRVP::sv2(1);
 
 // Test None-allowed py::arg argument policy
-class NoneTester { public: int answer = 42; };
+class NoneTester {
+public:
+    int answer = 42;
+};
 int none1(const NoneTester &obj) { return obj.answer; }
 int none2(NoneTester *obj) { return obj ? obj->answer : -1; }
 int none3(std::shared_ptr<NoneTester> &obj) { return obj ? obj->answer : -1; }
@@ -134,11 +140,15 @@ struct StrIssue {
     explicit StrIssue(int i) : val{i} {}
 };
 
-// Issues #854, #910: incompatible function args when member function/pointer is in unregistered base class
+// Issues #854, #910: incompatible function args when member function/pointer is in unregistered
+// base class
 class UnregisteredBase {
 public:
     void do_nothing() const {}
-    void increase_value() { rw_value++; ro_value += 0.25; }
+    void increase_value() {
+        rw_value++;
+        ro_value += 0.25;
+    }
     void set_int(int v) { rw_value = v; }
     int get_int() const { return rw_value; }
     double get_double() const { return ro_value; }
@@ -161,10 +171,10 @@ struct RefQualified {
 
 // Test rvalue ref param
 struct RValueRefParam {
-    std::size_t func1(std::string&& s) { return s.size(); }
-    std::size_t func2(std::string&& s) const { return s.size(); }
-    std::size_t func3(std::string&& s) & { return s.size(); }
-    std::size_t func4(std::string&& s) const & { return s.size(); }
+    std::size_t func1(std::string &&s) { return s.size(); }
+    std::size_t func2(std::string &&s) const { return s.size(); }
+    std::size_t func3(std::string &&s) & { return s.size(); }
+    std::size_t func4(std::string &&s) const & { return s.size(); }
 };
 
 TEST_SUBMODULE(methods_and_attributes, m) {
@@ -172,8 +182,8 @@ TEST_SUBMODULE(methods_and_attributes, m) {
     py::class_<ExampleMandA> emna(m, "ExampleMandA");
     emna.def(py::init<>())
         .def(py::init<int>())
-        .def(py::init<std::string&&>())
-        .def(py::init<const ExampleMandA&>())
+        .def(py::init<std::string &&>())
+        .def(py::init<const ExampleMandA &>())
         .def("add1", &ExampleMandA::add1)
         .def("add2", &ExampleMandA::add2)
         .def("add3", &ExampleMandA::add3)
@@ -198,16 +208,20 @@ TEST_SUBMODULE(methods_and_attributes, m) {
 #if defined(PYBIND11_OVERLOAD_CAST)
         .def("overloaded", py::overload_cast<>(&ExampleMandA::overloaded))
         .def("overloaded", py::overload_cast<int>(&ExampleMandA::overloaded))
-        .def("overloaded", py::overload_cast<int,   float>(&ExampleMandA::overloaded))
-        .def("overloaded", py::overload_cast<float,   int>(&ExampleMandA::overloaded))
-        .def("overloaded", py::overload_cast<int,     int>(&ExampleMandA::overloaded))
+        .def("overloaded", py::overload_cast<int, float>(&ExampleMandA::overloaded))
+        .def("overloaded", py::overload_cast<float, int>(&ExampleMandA::overloaded))
+        .def("overloaded", py::overload_cast<int, int>(&ExampleMandA::overloaded))
         .def("overloaded", py::overload_cast<float, float>(&ExampleMandA::overloaded))
         .def("overloaded_float", py::overload_cast<float, float>(&ExampleMandA::overloaded))
-        .def("overloaded_const", py::overload_cast<int         >(&ExampleMandA::overloaded, py::const_))
-        .def("overloaded_const", py::overload_cast<int,   float>(&ExampleMandA::overloaded, py::const_))
-        .def("overloaded_const", py::overload_cast<float,   int>(&ExampleMandA::overloaded, py::const_))
-        .def("overloaded_const", py::overload_cast<int,     int>(&ExampleMandA::overloaded, py::const_))
-        .def("overloaded_const", py::overload_cast<float, float>(&ExampleMandA::overloaded, py::const_))
+        .def("overloaded_const", py::overload_cast<int>(&ExampleMandA::overloaded, py::const_))
+        .def("overloaded_const",
+             py::overload_cast<int, float>(&ExampleMandA::overloaded, py::const_))
+        .def("overloaded_const",
+             py::overload_cast<float, int>(&ExampleMandA::overloaded, py::const_))
+        .def("overloaded_const",
+             py::overload_cast<int, int>(&ExampleMandA::overloaded, py::const_))
+        .def("overloaded_const",
+             py::overload_cast<float, float>(&ExampleMandA::overloaded, py::const_))
 #else
         // Use both the traditional static_cast method and the C++11 compatible overload_cast_
         .def("overloaded", overload_cast_<>()(&ExampleMandA::overloaded))
@@ -225,16 +239,29 @@ TEST_SUBMODULE(methods_and_attributes, m) {
 #endif
         // test_no_mixed_overloads
         // Raise error if trying to mix static/non-static overloads on the same name:
-        .def_static("add_mixed_overloads1", []() {
-            auto emna = py::reinterpret_borrow<py::class_<ExampleMandA>>(py::module_::import("pybind11_tests.methods_and_attributes").attr("ExampleMandA"));
-            emna.def       ("overload_mixed1", static_cast<py::str (ExampleMandA::*)(int, int)>(&ExampleMandA::overloaded))
-                .def_static("overload_mixed1", static_cast<py::str (              *)(float   )>(&ExampleMandA::overloaded));
-        })
-        .def_static("add_mixed_overloads2", []() {
-            auto emna = py::reinterpret_borrow<py::class_<ExampleMandA>>(py::module_::import("pybind11_tests.methods_and_attributes").attr("ExampleMandA"));
-            emna.def_static("overload_mixed2", static_cast<py::str (              *)(float   )>(&ExampleMandA::overloaded))
-                .def       ("overload_mixed2", static_cast<py::str (ExampleMandA::*)(int, int)>(&ExampleMandA::overloaded));
-        })
+        .def_static("add_mixed_overloads1",
+                    []() {
+                        auto emna = py::reinterpret_borrow<py::class_<ExampleMandA>>(
+                            py::module_::import("pybind11_tests.methods_and_attributes")
+                                .attr("ExampleMandA"));
+                        emna.def("overload_mixed1",
+                                 static_cast<py::str (ExampleMandA::*)(int, int)>(
+                                     &ExampleMandA::overloaded))
+                            .def_static(
+                                "overload_mixed1",
+                                static_cast<py::str (*)(float)>(&ExampleMandA::overloaded));
+                    })
+        .def_static("add_mixed_overloads2",
+                    []() {
+                        auto emna = py::reinterpret_borrow<py::class_<ExampleMandA>>(
+                            py::module_::import("pybind11_tests.methods_and_attributes")
+                                .attr("ExampleMandA"));
+                        emna.def_static("overload_mixed2",
+                                        static_cast<py::str (*)(float)>(&ExampleMandA::overloaded))
+                            .def("overload_mixed2",
+                                 static_cast<py::str (ExampleMandA::*)(int, int)>(
+                                     &ExampleMandA::overloaded));
+                    })
         .def("__str__", &ExampleMandA::toString)
         .def_readwrite("value", &ExampleMandA::value);
 
@@ -307,7 +334,7 @@ TEST_SUBMODULE(methods_and_attributes, m) {
                                       [](const py::object &) { return UserType(1); });
 
     // test_metaclass_override
-    struct MetaclassOverride { };
+    struct MetaclassOverride {};
     py::class_<MetaclassOverride>(m, "MetaclassOverride", py::metaclass((PyObject *) &PyType_Type))
         .def_property_readonly_static("readonly", [](const py::object &) { return 1; });
 
@@ -315,22 +342,21 @@ TEST_SUBMODULE(methods_and_attributes, m) {
     m.def("overload_order", [](const std::string &) { return 1; });
     m.def("overload_order", [](const std::string &) { return 2; });
     m.def("overload_order", [](int) { return 3; });
-    m.def("overload_order", [](int) { return 4; }, py::prepend{});
+    m.def(
+        "overload_order", [](int) { return 4; }, py::prepend{});
 
 #if !defined(PYPY_VERSION)
     // test_dynamic_attributes
     class DynamicClass {
     public:
         DynamicClass() { print_default_created(this); }
-        DynamicClass(const DynamicClass&) = delete;
+        DynamicClass(const DynamicClass &) = delete;
         ~DynamicClass() { print_destroyed(this); }
     };
-    py::class_<DynamicClass>(m, "DynamicClass", py::dynamic_attr())
-        .def(py::init());
+    py::class_<DynamicClass>(m, "DynamicClass", py::dynamic_attr()).def(py::init());
 
-    class CppDerivedDynamicClass : public DynamicClass { };
-    py::class_<CppDerivedDynamicClass, DynamicClass>(m, "CppDerivedDynamicClass")
-        .def(py::init());
+    class CppDerivedDynamicClass : public DynamicClass {};
+    py::class_<CppDerivedDynamicClass, DynamicClass>(m, "CppDerivedDynamicClass").def(py::init());
 #endif
 
     // test_bad_arg_default
@@ -340,20 +366,27 @@ TEST_SUBMODULE(methods_and_attributes, m) {
 #else
     m.attr("debug_enabled") = false;
 #endif
-    m.def("bad_arg_def_named", []{
+    m.def("bad_arg_def_named", [] {
         auto m = py::module_::import("pybind11_tests");
-        m.def("should_fail", [](int, UnregisteredType) {}, py::arg(), py::arg("a") = UnregisteredType());
+        m.def(
+            "should_fail",
+            [](int, UnregisteredType) {},
+            py::arg(),
+            py::arg("a") = UnregisteredType());
     });
-    m.def("bad_arg_def_unnamed", []{
+    m.def("bad_arg_def_unnamed", [] {
         auto m = py::module_::import("pybind11_tests");
-        m.def("should_fail", [](int, UnregisteredType) {}, py::arg(), py::arg() = UnregisteredType());
+        m.def(
+            "should_fail",
+            [](int, UnregisteredType) {},
+            py::arg(),
+            py::arg() = UnregisteredType());
     });
 
     // [workaround(intel)] ICC 20/21 breaks with py::arg().stuff, using py::arg{}.stuff works.
 
     // test_accepts_none
-    py::class_<NoneTester, std::shared_ptr<NoneTester>>(m, "NoneTester")
-        .def(py::init<>());
+    py::class_<NoneTester, std::shared_ptr<NoneTester>>(m, "NoneTester").def(py::init<>());
     m.def("no_none1", &none1, py::arg{}.none(false));
     m.def("no_none2", &none2, py::arg{}.none(false));
     m.def("no_none3", &none3, py::arg{}.none(false));
@@ -371,21 +404,19 @@ TEST_SUBMODULE(methods_and_attributes, m) {
     // test_casts_none
     // Issue #2778: implicit casting from None to object (not pointer)
     py::class_<NoneCastTester>(m, "NoneCastTester")
-          .def(py::init<>())
-          .def(py::init<int>())
-          .def(py::init([](py::none const&) { return NoneCastTester{}; }));
+        .def(py::init<>())
+        .def(py::init<int>())
+        .def(py::init([](py::none const &) { return NoneCastTester{}; }));
     py::implicitly_convertible<py::none, NoneCastTester>();
-    m.def("ok_obj_or_none", [](NoneCastTester const& foo) { return foo.answer; });
-
+    m.def("ok_obj_or_none", [](NoneCastTester const &foo) { return foo.answer; });
 
     // test_str_issue
     // Issue #283: __str__ called on uninitialized instance when constructor arguments invalid
     py::class_<StrIssue>(m, "StrIssue")
         .def(py::init<int>())
         .def(py::init<>())
-        .def("__str__", [](const StrIssue &si) {
-            return "StrIssue[" + std::to_string(si.val) + "]"; }
-        );
+        .def("__str__",
+             [](const StrIssue &si) { return "StrIssue[" + std::to_string(si.val) + "]"; });
 
     // test_unregistered_base_implementations
     //
@@ -408,7 +439,8 @@ TEST_SUBMODULE(methods_and_attributes, m) {
         // This one is in the registered class:
         .def("sum", &RegisteredDerived::sum);
 
-    using Adapted = decltype(py::method_adaptor<RegisteredDerived>(&RegisteredDerived::do_nothing));
+    using Adapted
+        = decltype(py::method_adaptor<RegisteredDerived>(&RegisteredDerived::do_nothing));
     static_assert(std::is_same<Adapted, void (RegisteredDerived::*)() const>::value, "");
 
     // test_methods_and_attributes
diff --git a/tests/test_modules.cpp b/tests/test_modules.cpp
index ce61c1a25c..8b91444ebf 100644
--- a/tests/test_modules.cpp
+++ b/tests/test_modules.cpp
@@ -8,8 +8,8 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include "constructor_stats.h"
+#include "pybind11_tests.h"
 
 TEST_SUBMODULE(modules, m) {
     // test_nested_modules
@@ -22,23 +22,30 @@ TEST_SUBMODULE(modules, m) {
     public:
         explicit A(int v) : v(v) { print_created(this, v); }
         ~A() { print_destroyed(this); }
-        A(const A&) { print_copy_created(this); }
-        A& operator=(const A &copy) { print_copy_assigned(this); v = copy.v; return *this; }
+        A(const A &) { print_copy_created(this); }
+        A &operator=(const A &copy) {
+            print_copy_assigned(this);
+            v = copy.v;
+            return *this;
+        }
         std::string toString() const { return "A[" + std::to_string(v) + "]"; }
 
     private:
         int v;
     };
-    py::class_<A>(m_sub, "A")
-        .def(py::init<int>())
-        .def("__repr__", &A::toString);
+    py::class_<A>(m_sub, "A").def(py::init<int>()).def("__repr__", &A::toString);
 
     class B {
     public:
         B() { print_default_created(this); }
         ~B() { print_destroyed(this); }
-        B(const B&) { print_copy_created(this); }
-        B& operator=(const B &copy) { print_copy_assigned(this); a1 = copy.a1; a2 = copy.a2; return *this; }
+        B(const B &) { print_copy_created(this); }
+        B &operator=(const B &copy) {
+            print_copy_assigned(this);
+            a1 = copy.a1;
+            a2 = copy.a2;
+            return *this;
+        }
         A &get_a1() { return a1; }
         A &get_a2() { return a2; }
 
@@ -47,9 +54,16 @@ TEST_SUBMODULE(modules, m) {
     };
     py::class_<B>(m_sub, "B")
         .def(py::init<>())
-        .def("get_a1", &B::get_a1, "Return the internal A 1", py::return_value_policy::reference_internal)
-        .def("get_a2", &B::get_a2, "Return the internal A 2", py::return_value_policy::reference_internal)
-        .def_readwrite("a1", &B::a1)  // def_readonly uses an internal reference return policy by default
+        .def("get_a1",
+             &B::get_a1,
+             "Return the internal A 1",
+             py::return_value_policy::reference_internal)
+        .def("get_a2",
+             &B::get_a2,
+             "Return the internal A 2",
+             py::return_value_policy::reference_internal)
+        .def_readwrite("a1",
+                       &B::a1) // def_readonly uses an internal reference return policy by default
         .def_readwrite("a2", &B::a2);
 
     // This is intentionally "py::module" to verify it still can be used in place of "py::module_"
@@ -58,13 +72,14 @@ TEST_SUBMODULE(modules, m) {
     // test_duplicate_registration
     // Registering two things with the same name
     m.def("duplicate_registration", []() {
-        class Dupe1 { };
-        class Dupe2 { };
-        class Dupe3 { };
-        class DupeException { };
+        class Dupe1 {};
+        class Dupe2 {};
+        class Dupe3 {};
+        class DupeException {};
 
         // Go ahead and leak, until we have a non-leaking py::module_ constructor
-        auto dm = py::module_::create_extension_module("dummy", nullptr, new py::module_::module_def);
+        auto dm
+            = py::module_::create_extension_module("dummy", nullptr, new py::module_::module_def);
         auto failures = py::list();
 
         py::class_<Dupe1>(dm, "Dupe1");
@@ -75,27 +90,33 @@ TEST_SUBMODULE(modules, m) {
         try {
             py::class_<Dupe1>(dm, "Dupe1");
             failures.append("Dupe1 class");
-        } catch (std::runtime_error &) {}
+        } catch (std::runtime_error &) {
+        }
         try {
             dm.def("Dupe1", []() { return Dupe1(); });
             failures.append("Dupe1 function");
-        } catch (std::runtime_error &) {}
+        } catch (std::runtime_error &) {
+        }
         try {
             py::class_<Dupe3>(dm, "dupe1_factory");
             failures.append("dupe1_factory");
-        } catch (std::runtime_error &) {}
+        } catch (std::runtime_error &) {
+        }
         try {
             py::exception<Dupe3>(dm, "Dupe2");
             failures.append("Dupe2");
-        } catch (std::runtime_error &) {}
+        } catch (std::runtime_error &) {
+        }
         try {
             dm.def("DupeException", []() { return 30; });
             failures.append("DupeException1");
-        } catch (std::runtime_error &) {}
+        } catch (std::runtime_error &) {
+        }
         try {
             py::class_<DupeException>(dm, "DupeException");
             failures.append("DupeException2");
-        } catch (std::runtime_error &) {}
+        } catch (std::runtime_error &) {
+        }
 
         return failures;
     });
diff --git a/tests/test_multiple_inheritance.cpp b/tests/test_multiple_inheritance.cpp
index 4689df4e46..5916ae9010 100644
--- a/tests/test_multiple_inheritance.cpp
+++ b/tests/test_multiple_inheritance.cpp
@@ -8,14 +8,15 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include "constructor_stats.h"
+#include "pybind11_tests.h"
 
 namespace {
 
 // Many bases for testing that multiple inheritance from many classes (i.e. requiring extra
 // space for holder constructed flags) works.
-template <int N> struct BaseN {
+template <int N>
+struct BaseN {
     explicit BaseN(int i) : i(i) {}
     int i;
 };
@@ -57,13 +58,23 @@ struct Base2a {
     int i;
 };
 struct Base12a : Base1a, Base2a {
-    Base12a(int i, int j) : Base1a(i), Base2a(j) { }
+    Base12a(int i, int j) : Base1a(i), Base2a(j) {}
 };
 
 // test_mi_unaligned_base
 // test_mi_base_return
-struct I801B1 { int a = 1; I801B1() = default; I801B1(const I801B1 &) = default; virtual ~I801B1() = default; };
-struct I801B2 { int b = 2; I801B2() = default; I801B2(const I801B2 &) = default; virtual ~I801B2() = default; };
+struct I801B1 {
+    int a = 1;
+    I801B1() = default;
+    I801B1(const I801B1 &) = default;
+    virtual ~I801B1() = default;
+};
+struct I801B2 {
+    int b = 2;
+    I801B2() = default;
+    I801B2(const I801B2 &) = default;
+    virtual ~I801B2() = default;
+};
 struct I801C : I801B1, I801B2 {};
 struct I801D : I801C {}; // Indirect MI
 
@@ -82,8 +93,7 @@ TEST_SUBMODULE(multiple_inheritance, m) {
         int i;
     };
     py::class_<Base1> b1(m, "Base1");
-    b1.def(py::init<int>())
-      .def("foo", &Base1::foo);
+    b1.def(py::init<int>()).def("foo", &Base1::foo);
 
     struct Base2 {
         explicit Base2(int i) : i(i) {}
@@ -91,42 +101,49 @@ TEST_SUBMODULE(multiple_inheritance, m) {
         int i;
     };
     py::class_<Base2> b2(m, "Base2");
-    b2.def(py::init<int>())
-      .def("bar", &Base2::bar);
-
+    b2.def(py::init<int>()).def("bar", &Base2::bar);
 
     // test_multiple_inheritance_cpp
     struct Base12 : Base1, Base2 {
-        Base12(int i, int j) : Base1(i), Base2(j) { }
+        Base12(int i, int j) : Base1(i), Base2(j) {}
     };
     struct MIType : Base12 {
-        MIType(int i, int j) : Base12(i, j) { }
+        MIType(int i, int j) : Base12(i, j) {}
     };
     py::class_<Base12, Base1, Base2>(m, "Base12");
-    py::class_<MIType, Base12>(m, "MIType")
-        .def(py::init<int, int>());
-
+    py::class_<MIType, Base12>(m, "MIType").def(py::init<int, int>());
 
     // test_multiple_inheritance_python_many_bases
 #define PYBIND11_BASEN(N)                                                                         \
     py::class_<BaseN<(N)>>(m, "BaseN" #N).def(py::init<int>()).def("f" #N, [](BaseN<N> &b) {      \
         return b.i + (N);                                                                         \
     })
-    PYBIND11_BASEN( 1); PYBIND11_BASEN( 2); PYBIND11_BASEN( 3); PYBIND11_BASEN( 4);
-    PYBIND11_BASEN( 5); PYBIND11_BASEN( 6); PYBIND11_BASEN( 7); PYBIND11_BASEN( 8);
-    PYBIND11_BASEN( 9); PYBIND11_BASEN(10); PYBIND11_BASEN(11); PYBIND11_BASEN(12);
-    PYBIND11_BASEN(13); PYBIND11_BASEN(14); PYBIND11_BASEN(15); PYBIND11_BASEN(16);
+    PYBIND11_BASEN(1);
+    PYBIND11_BASEN(2);
+    PYBIND11_BASEN(3);
+    PYBIND11_BASEN(4);
+    PYBIND11_BASEN(5);
+    PYBIND11_BASEN(6);
+    PYBIND11_BASEN(7);
+    PYBIND11_BASEN(8);
+    PYBIND11_BASEN(9);
+    PYBIND11_BASEN(10);
+    PYBIND11_BASEN(11);
+    PYBIND11_BASEN(12);
+    PYBIND11_BASEN(13);
+    PYBIND11_BASEN(14);
+    PYBIND11_BASEN(15);
+    PYBIND11_BASEN(16);
     PYBIND11_BASEN(17);
 
     // Uncommenting this should result in a compile time failure (MI can only be specified via
-    // template parameters because pybind has to know the types involved; see discussion in #742 for
-    // details).
-//    struct Base12v2 : Base1, Base2 {
-//        Base12v2(int i, int j) : Base1(i), Base2(j) { }
-//    };
-//    py::class_<Base12v2>(m, "Base12v2", b1, b2)
-//        .def(py::init<int, int>());
-
+    // template parameters because pybind has to know the types involved; see discussion in #742
+    // for details).
+    //    struct Base12v2 : Base1, Base2 {
+    //        Base12v2(int i, int j) : Base1(i), Base2(j) { }
+    //    };
+    //    py::class_<Base12v2>(m, "Base12v2", b1, b2)
+    //        .def(py::init<int, int>());
 
     // test_multiple_inheritance_virtbase
     // Test the case where not all base classes are specified, and where pybind11 requires the
@@ -139,8 +156,8 @@ TEST_SUBMODULE(multiple_inheritance, m) {
         .def(py::init<int>())
         .def("bar", &Base2a::bar);
 
-    py::class_<Base12a, /* Base1 missing */ Base2a,
-               std::shared_ptr<Base12a>>(m, "Base12a", py::multiple_inheritance())
+    py::class_<Base12a, /* Base1 missing */ Base2a, std::shared_ptr<Base12a>>(
+        m, "Base12a", py::multiple_inheritance())
         .def(py::init<int, int>());
 
     m.def("bar_base2a", [](Base2a *b) { return b->bar(); });
@@ -150,11 +167,18 @@ TEST_SUBMODULE(multiple_inheritance, m) {
     // test_mi_base_return
     // Issue #801: invalid casting to derived type with MI bases
     // Unregistered classes:
-    struct I801B3 { int c = 3; virtual ~I801B3() = default; };
+    struct I801B3 {
+        int c = 3;
+        virtual ~I801B3() = default;
+    };
     struct I801E : I801B3, I801D {};
 
-    py::class_<I801B1, std::shared_ptr<I801B1>>(m, "I801B1").def(py::init<>()).def_readonly("a", &I801B1::a);
-    py::class_<I801B2, std::shared_ptr<I801B2>>(m, "I801B2").def(py::init<>()).def_readonly("b", &I801B2::b);
+    py::class_<I801B1, std::shared_ptr<I801B1>>(m, "I801B1")
+        .def(py::init<>())
+        .def_readonly("a", &I801B1::a);
+    py::class_<I801B2, std::shared_ptr<I801B2>>(m, "I801B2")
+        .def(py::init<>())
+        .def_readonly("b", &I801B2::b);
     py::class_<I801C, I801B1, I801B2, std::shared_ptr<I801C>>(m, "I801C").def(py::init<>());
     py::class_<I801D, I801C, std::shared_ptr<I801D>>(m, "I801D").def(py::init<>());
 
@@ -179,11 +203,8 @@ TEST_SUBMODULE(multiple_inheritance, m) {
     m.def("i801e_c", []() -> I801C * { return new I801E(); });
     m.def("i801e_b2", []() -> I801B2 * { return new I801E(); });
 
-
     // test_mi_static_properties
-    py::class_<Vanilla>(m, "Vanilla")
-        .def(py::init<>())
-        .def("vanilla", &Vanilla::vanilla);
+    py::class_<Vanilla>(m, "Vanilla").def(py::init<>()).def("vanilla", &Vanilla::vanilla);
 
     py::class_<WithStatic1>(m, "WithStatic1")
         .def(py::init<>())
@@ -195,22 +216,19 @@ TEST_SUBMODULE(multiple_inheritance, m) {
         .def_static("static_func2", &WithStatic2::static_func2)
         .def_readwrite_static("static_value2", &WithStatic2::static_value2);
 
-    py::class_<VanillaStaticMix1, Vanilla, WithStatic1, WithStatic2>(
-        m, "VanillaStaticMix1")
+    py::class_<VanillaStaticMix1, Vanilla, WithStatic1, WithStatic2>(m, "VanillaStaticMix1")
         .def(py::init<>())
         .def_static("static_func", &VanillaStaticMix1::static_func)
         .def_readwrite_static("static_value", &VanillaStaticMix1::static_value);
 
-    py::class_<VanillaStaticMix2, WithStatic1, Vanilla, WithStatic2>(
-        m, "VanillaStaticMix2")
+    py::class_<VanillaStaticMix2, WithStatic1, Vanilla, WithStatic2>(m, "VanillaStaticMix2")
         .def(py::init<>())
         .def_static("static_func", &VanillaStaticMix2::static_func)
         .def_readwrite_static("static_value", &VanillaStaticMix2::static_value);
 
-
-    struct WithDict { };
-    struct VanillaDictMix1 : Vanilla, WithDict { };
-    struct VanillaDictMix2 : WithDict, Vanilla { };
+    struct WithDict {};
+    struct VanillaDictMix1 : Vanilla, WithDict {};
+    struct VanillaDictMix2 : WithDict, Vanilla {};
     py::class_<WithDict>(m, "WithDict", py::dynamic_attr()).def(py::init<>());
     py::class_<VanillaDictMix1, Vanilla, WithDict>(m, "VanillaDictMix1").def(py::init<>());
     py::class_<VanillaDictMix2, WithDict, Vanilla>(m, "VanillaDictMix2").def(py::init<>());
@@ -218,18 +236,25 @@ TEST_SUBMODULE(multiple_inheritance, m) {
     // test_diamond_inheritance
     // Issue #959: segfault when constructing diamond inheritance instance
     // All of these have int members so that there will be various unequal pointers involved.
-    struct B { int b; B() = default; B(const B&) = default; virtual ~B() = default; };
-    struct C0 : public virtual B { int c0; };
-    struct C1 : public virtual B { int c1; };
-    struct D : public C0, public C1 { int d; };
-    py::class_<B>(m, "B")
-        .def("b", [](B *self) { return self; });
-    py::class_<C0, B>(m, "C0")
-        .def("c0", [](C0 *self) { return self; });
-    py::class_<C1, B>(m, "C1")
-        .def("c1", [](C1 *self) { return self; });
-    py::class_<D, C0, C1>(m, "D")
-        .def(py::init<>());
+    struct B {
+        int b;
+        B() = default;
+        B(const B &) = default;
+        virtual ~B() = default;
+    };
+    struct C0 : public virtual B {
+        int c0;
+    };
+    struct C1 : public virtual B {
+        int c1;
+    };
+    struct D : public C0, public C1 {
+        int d;
+    };
+    py::class_<B>(m, "B").def("b", [](B *self) { return self; });
+    py::class_<C0, B>(m, "C0").def("c0", [](C0 *self) { return self; });
+    py::class_<C1, B>(m, "C1").def("c1", [](C1 *self) { return self; });
+    py::class_<D, C0, C1>(m, "D").def(py::init<>());
 
     // test_pr3635_diamond_*
     // - functions are get_{base}_{var}, return {var}
diff --git a/tests/test_numpy_array.cpp b/tests/test_numpy_array.cpp
index 30a71acc9b..b454117ec8 100644
--- a/tests/test_numpy_array.cpp
+++ b/tests/test_numpy_array.cpp
@@ -7,11 +7,11 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
-
 #include <pybind11/numpy.h>
 #include <pybind11/stl.h>
 
+#include "pybind11_tests.h"
+
 #include <cstdint>
 #include <utility>
 
@@ -22,7 +22,7 @@ struct DtypeCheck {
 };
 
 template <typename T>
-DtypeCheck get_dtype_check(const char* name) {
+DtypeCheck get_dtype_check(const char *name) {
     py::module_ np = py::module_::import("numpy");
     DtypeCheck check{};
     check.numpy = np.attr("dtype")(np.attr(name));
@@ -31,17 +31,15 @@ DtypeCheck get_dtype_check(const char* name) {
 }
 
 std::vector<DtypeCheck> get_concrete_dtype_checks() {
-    return {
-        // Normalization
-        get_dtype_check<std::int8_t>("int8"),
-        get_dtype_check<std::uint8_t>("uint8"),
-        get_dtype_check<std::int16_t>("int16"),
-        get_dtype_check<std::uint16_t>("uint16"),
-        get_dtype_check<std::int32_t>("int32"),
-        get_dtype_check<std::uint32_t>("uint32"),
-        get_dtype_check<std::int64_t>("int64"),
-        get_dtype_check<std::uint64_t>("uint64")
-    };
+    return {// Normalization
+            get_dtype_check<std::int8_t>("int8"),
+            get_dtype_check<std::uint8_t>("uint8"),
+            get_dtype_check<std::int16_t>("int16"),
+            get_dtype_check<std::uint16_t>("uint16"),
+            get_dtype_check<std::int32_t>("int32"),
+            get_dtype_check<std::uint32_t>("uint32"),
+            get_dtype_check<std::int64_t>("int64"),
+            get_dtype_check<std::uint64_t>("uint64")};
 }
 
 struct DtypeSizeCheck {
@@ -80,43 +78,68 @@ using arr = py::array;
 using arr_t = py::array_t<uint16_t, 0>;
 static_assert(std::is_same<arr_t::value_type, uint16_t>::value, "");
 
-template<typename... Ix> arr data(const arr& a, Ix... index) {
+template <typename... Ix>
+arr data(const arr &a, Ix... index) {
     return arr(a.nbytes() - a.offset_at(index...), (const uint8_t *) a.data(index...));
 }
 
-template<typename... Ix> arr data_t(const arr_t& a, Ix... index) {
+template <typename... Ix>
+arr data_t(const arr_t &a, Ix... index) {
     return arr(a.size() - a.index_at(index...), a.data(index...));
 }
 
-template<typename... Ix> arr& mutate_data(arr& a, Ix... index) {
-    auto ptr = (uint8_t *) a.mutable_data(index...);
+template <typename... Ix>
+arr &mutate_data(arr &a, Ix... index) {
+    auto *ptr = (uint8_t *) a.mutable_data(index...);
     for (py::ssize_t i = 0; i < a.nbytes() - a.offset_at(index...); i++)
         ptr[i] = (uint8_t) (ptr[i] * 2);
     return a;
 }
 
-template<typename... Ix> arr_t& mutate_data_t(arr_t& a, Ix... index) {
+template <typename... Ix>
+arr_t &mutate_data_t(arr_t &a, Ix... index) {
     auto ptr = a.mutable_data(index...);
     for (py::ssize_t i = 0; i < a.size() - a.index_at(index...); i++)
         ptr[i]++;
     return a;
 }
 
-template<typename... Ix> py::ssize_t index_at(const arr& a, Ix... idx) { return a.index_at(idx...); }
-template<typename... Ix> py::ssize_t index_at_t(const arr_t& a, Ix... idx) { return a.index_at(idx...); }
-template<typename... Ix> py::ssize_t offset_at(const arr& a, Ix... idx) { return a.offset_at(idx...); }
-template<typename... Ix> py::ssize_t offset_at_t(const arr_t& a, Ix... idx) { return a.offset_at(idx...); }
-template<typename... Ix> py::ssize_t at_t(const arr_t& a, Ix... idx) { return a.at(idx...); }
-template<typename... Ix> arr_t& mutate_at_t(arr_t& a, Ix... idx) { a.mutable_at(idx...)++; return a; }
-
-#define def_index_fn(name, type) \
-    sm.def(#name, [](type a) { return name(a); }); \
-    sm.def(#name, [](type a, int i) { return name(a, i); }); \
-    sm.def(#name, [](type a, int i, int j) { return name(a, i, j); }); \
+template <typename... Ix>
+py::ssize_t index_at(const arr &a, Ix... idx) {
+    return a.index_at(idx...);
+}
+template <typename... Ix>
+py::ssize_t index_at_t(const arr_t &a, Ix... idx) {
+    return a.index_at(idx...);
+}
+template <typename... Ix>
+py::ssize_t offset_at(const arr &a, Ix... idx) {
+    return a.offset_at(idx...);
+}
+template <typename... Ix>
+py::ssize_t offset_at_t(const arr_t &a, Ix... idx) {
+    return a.offset_at(idx...);
+}
+template <typename... Ix>
+py::ssize_t at_t(const arr_t &a, Ix... idx) {
+    return a.at(idx...);
+}
+template <typename... Ix>
+arr_t &mutate_at_t(arr_t &a, Ix... idx) {
+    a.mutable_at(idx...)++;
+    return a;
+}
+
+#define def_index_fn(name, type)                                                                  \
+    sm.def(#name, [](type a) { return name(a); });                                                \
+    sm.def(#name, [](type a, int i) { return name(a, i); });                                      \
+    sm.def(#name, [](type a, int i, int j) { return name(a, i, j); });                            \
     sm.def(#name, [](type a, int i, int j, int k) { return name(a, i, j, k); });
 
-template <typename T, typename T2> py::handle auxiliaries(T &&r, T2 &&r2) {
-    if (r.ndim() != 2) throw std::domain_error("error: ndim != 2");
+template <typename T, typename T2>
+py::handle auxiliaries(T &&r, T2 &&r2) {
+    if (r.ndim() != 2)
+        throw std::domain_error("error: ndim != 2");
     py::list l;
     l.append(*r.data(0, 0));
     l.append(*r2.mutable_data(0, 0));
@@ -134,16 +157,18 @@ template <typename T, typename T2> py::handle auxiliaries(T &&r, T2 &&r2) {
 static int data_i = 42;
 
 TEST_SUBMODULE(numpy_array, sm) {
-    try { py::module_::import("numpy"); }
-    catch (...) { return; }
+    try {
+        py::module_::import("numpy");
+    } catch (...) {
+        return;
+    }
 
     // test_dtypes
     py::class_<DtypeCheck>(sm, "DtypeCheck")
         .def_readonly("numpy", &DtypeCheck::numpy)
         .def_readonly("pybind11", &DtypeCheck::pybind11)
-        .def("__repr__", [](const DtypeCheck& self) {
-            return py::str("<DtypeCheck numpy={} pybind11={}>").format(
-                self.numpy, self.pybind11);
+        .def("__repr__", [](const DtypeCheck &self) {
+            return py::str("<DtypeCheck numpy={} pybind11={}>").format(self.numpy, self.pybind11);
         });
     sm.def("get_concrete_dtype_checks", &get_concrete_dtype_checks);
 
@@ -151,41 +176,41 @@ TEST_SUBMODULE(numpy_array, sm) {
         .def_readonly("name", &DtypeSizeCheck::name)
         .def_readonly("size_cpp", &DtypeSizeCheck::size_cpp)
         .def_readonly("size_numpy", &DtypeSizeCheck::size_numpy)
-        .def("__repr__", [](const DtypeSizeCheck& self) {
-            return py::str("<DtypeSizeCheck name='{}' size_cpp={} size_numpy={} dtype={}>").format(
-                self.name, self.size_cpp, self.size_numpy, self.dtype);
+        .def("__repr__", [](const DtypeSizeCheck &self) {
+            return py::str("<DtypeSizeCheck name='{}' size_cpp={} size_numpy={} dtype={}>")
+                .format(self.name, self.size_cpp, self.size_numpy, self.dtype);
         });
     sm.def("get_platform_dtype_size_checks", &get_platform_dtype_size_checks);
 
     // test_array_attributes
-    sm.def("ndim", [](const arr& a) { return a.ndim(); });
-    sm.def("shape", [](const arr& a) { return arr(a.ndim(), a.shape()); });
-    sm.def("shape", [](const arr& a, py::ssize_t dim) { return a.shape(dim); });
-    sm.def("strides", [](const arr& a) { return arr(a.ndim(), a.strides()); });
-    sm.def("strides", [](const arr& a, py::ssize_t dim) { return a.strides(dim); });
-    sm.def("writeable", [](const arr& a) { return a.writeable(); });
-    sm.def("size", [](const arr& a) { return a.size(); });
-    sm.def("itemsize", [](const arr& a) { return a.itemsize(); });
-    sm.def("nbytes", [](const arr& a) { return a.nbytes(); });
-    sm.def("owndata", [](const arr& a) { return a.owndata(); });
+    sm.def("ndim", [](const arr &a) { return a.ndim(); });
+    sm.def("shape", [](const arr &a) { return arr(a.ndim(), a.shape()); });
+    sm.def("shape", [](const arr &a, py::ssize_t dim) { return a.shape(dim); });
+    sm.def("strides", [](const arr &a) { return arr(a.ndim(), a.strides()); });
+    sm.def("strides", [](const arr &a, py::ssize_t dim) { return a.strides(dim); });
+    sm.def("writeable", [](const arr &a) { return a.writeable(); });
+    sm.def("size", [](const arr &a) { return a.size(); });
+    sm.def("itemsize", [](const arr &a) { return a.itemsize(); });
+    sm.def("nbytes", [](const arr &a) { return a.nbytes(); });
+    sm.def("owndata", [](const arr &a) { return a.owndata(); });
 
     // test_index_offset
-    def_index_fn(index_at, const arr&);
-    def_index_fn(index_at_t, const arr_t&);
-    def_index_fn(offset_at, const arr&);
-    def_index_fn(offset_at_t, const arr_t&);
+    def_index_fn(index_at, const arr &);
+    def_index_fn(index_at_t, const arr_t &);
+    def_index_fn(offset_at, const arr &);
+    def_index_fn(offset_at_t, const arr_t &);
     // test_data
-    def_index_fn(data, const arr&);
-    def_index_fn(data_t, const arr_t&);
+    def_index_fn(data, const arr &);
+    def_index_fn(data_t, const arr_t &);
     // test_mutate_data, test_mutate_readonly
-    def_index_fn(mutate_data, arr&);
-    def_index_fn(mutate_data_t, arr_t&);
-    def_index_fn(at_t, const arr_t&);
-    def_index_fn(mutate_at_t, arr_t&);
+    def_index_fn(mutate_data, arr &);
+    def_index_fn(mutate_data_t, arr_t &);
+    def_index_fn(at_t, const arr_t &);
+    def_index_fn(mutate_at_t, arr_t &);
 
     // test_make_c_f_array
-    sm.def("make_f_array", [] { return py::array_t<float>({ 2, 2 }, { 4, 8 }); });
-    sm.def("make_c_array", [] { return py::array_t<float>({ 2, 2 }, { 8, 4 }); });
+    sm.def("make_f_array", [] { return py::array_t<float>({2, 2}, {4, 8}); });
+    sm.def("make_c_array", [] { return py::array_t<float>({2, 2}, {8, 4}); });
 
     // test_empty_shaped_array
     sm.def("make_empty_shaped_array", [] { return py::array(py::dtype("f"), {}, {}); });
@@ -194,18 +219,16 @@ TEST_SUBMODULE(numpy_array, sm) {
 
     // test_wrap
     sm.def("wrap", [](const py::array &a) {
-        return py::array(
-            a.dtype(),
-            {a.shape(), a.shape() + a.ndim()},
-            {a.strides(), a.strides() + a.ndim()},
-            a.data(),
-            a
-        );
+        return py::array(a.dtype(),
+                         {a.shape(), a.shape() + a.ndim()},
+                         {a.strides(), a.strides() + a.ndim()},
+                         a.data(),
+                         a);
     });
 
     // test_numpy_view
     struct ArrayClass {
-        int data[2] = { 1, 2 };
+        int data[2] = {1, 2};
         ArrayClass() { py::print("ArrayClass()"); }
         ~ArrayClass() { py::print("~ArrayClass()"); }
     };
@@ -213,13 +236,12 @@ TEST_SUBMODULE(numpy_array, sm) {
         .def(py::init<>())
         .def("numpy_view", [](py::object &obj) {
             py::print("ArrayClass::numpy_view()");
-            auto &a = obj.cast<ArrayClass&>();
+            auto &a = obj.cast<ArrayClass &>();
             return py::array_t<int>({2}, {4}, a.data, obj);
-        }
-    );
+        });
 
     // test_cast_numpy_int64_to_uint64
-    sm.def("function_taking_uint64", [](uint64_t) { });
+    sm.def("function_taking_uint64", [](uint64_t) {});
 
     // test_isinstance
     sm.def("isinstance_untyped", [](py::object yes, py::object no) {
@@ -232,18 +254,14 @@ TEST_SUBMODULE(numpy_array, sm) {
 
     // test_constructors
     sm.def("default_constructors", []() {
-        return py::dict(
-            "array"_a=py::array(),
-            "array_t<int32>"_a=py::array_t<std::int32_t>(),
-            "array_t<double>"_a=py::array_t<double>()
-        );
+        return py::dict("array"_a = py::array(),
+                        "array_t<int32>"_a = py::array_t<std::int32_t>(),
+                        "array_t<double>"_a = py::array_t<double>());
     });
     sm.def("converting_constructors", [](const py::object &o) {
-        return py::dict(
-            "array"_a=py::array(o),
-            "array_t<int32>"_a=py::array_t<std::int32_t>(o),
-            "array_t<double>"_a=py::array_t<double>(o)
-        );
+        return py::dict("array"_a = py::array(o),
+                        "array_t<int32>"_a = py::array_t<std::int32_t>(o),
+                        "array_t<double>"_a = py::array_t<double>(o));
     });
 
     // test_overload_resolution
@@ -290,29 +308,33 @@ TEST_SUBMODULE(numpy_array, sm) {
     sm.def("issue685", [](const py::object &) { return "other"; });
 
     // test_array_unchecked_fixed_dims
-    sm.def("proxy_add2", [](py::array_t<double> a, double v) {
-        auto r = a.mutable_unchecked<2>();
-        for (py::ssize_t i = 0; i < r.shape(0); i++)
-            for (py::ssize_t j = 0; j < r.shape(1); j++)
-                r(i, j) += v;
-    }, py::arg{}.noconvert(), py::arg());
+    sm.def(
+        "proxy_add2",
+        [](py::array_t<double> a, double v) {
+            auto r = a.mutable_unchecked<2>();
+            for (py::ssize_t i = 0; i < r.shape(0); i++)
+                for (py::ssize_t j = 0; j < r.shape(1); j++)
+                    r(i, j) += v;
+        },
+        py::arg{}.noconvert(),
+        py::arg());
 
     sm.def("proxy_init3", [](double start) {
-        py::array_t<double, py::array::c_style> a({ 3, 3, 3 });
+        py::array_t<double, py::array::c_style> a({3, 3, 3});
         auto r = a.mutable_unchecked<3>();
         for (py::ssize_t i = 0; i < r.shape(0); i++)
-        for (py::ssize_t j = 0; j < r.shape(1); j++)
-        for (py::ssize_t k = 0; k < r.shape(2); k++)
-            r(i, j, k) = start++;
+            for (py::ssize_t j = 0; j < r.shape(1); j++)
+                for (py::ssize_t k = 0; k < r.shape(2); k++)
+                    r(i, j, k) = start++;
         return a;
     });
     sm.def("proxy_init3F", [](double start) {
-        py::array_t<double, py::array::f_style> a({ 3, 3, 3 });
+        py::array_t<double, py::array::f_style> a({3, 3, 3});
         auto r = a.mutable_unchecked<3>();
         for (py::ssize_t k = 0; k < r.shape(2); k++)
-        for (py::ssize_t j = 0; j < r.shape(1); j++)
-        for (py::ssize_t i = 0; i < r.shape(0); i++)
-            r(i, j, k) = start++;
+            for (py::ssize_t j = 0; j < r.shape(1); j++)
+                for (py::ssize_t i = 0; i < r.shape(0); i++)
+                    r(i, j, k) = start++;
         return a;
     });
     sm.def("proxy_squared_L2_norm", [](const py::array_t<double> &a) {
@@ -343,51 +365,61 @@ TEST_SUBMODULE(numpy_array, sm) {
 
     // test_array_unchecked_dyn_dims
     // Same as the above, but without a compile-time dimensions specification:
-    sm.def("proxy_add2_dyn", [](py::array_t<double> a, double v) {
-        auto r = a.mutable_unchecked();
-        if (r.ndim() != 2) throw std::domain_error("error: ndim != 2");
-        for (py::ssize_t i = 0; i < r.shape(0); i++)
-            for (py::ssize_t j = 0; j < r.shape(1); j++)
-                r(i, j) += v;
-    }, py::arg{}.noconvert(), py::arg());
+    sm.def(
+        "proxy_add2_dyn",
+        [](py::array_t<double> a, double v) {
+            auto r = a.mutable_unchecked();
+            if (r.ndim() != 2)
+                throw std::domain_error("error: ndim != 2");
+            for (py::ssize_t i = 0; i < r.shape(0); i++)
+                for (py::ssize_t j = 0; j < r.shape(1); j++)
+                    r(i, j) += v;
+        },
+        py::arg{}.noconvert(),
+        py::arg());
     sm.def("proxy_init3_dyn", [](double start) {
-        py::array_t<double, py::array::c_style> a({ 3, 3, 3 });
+        py::array_t<double, py::array::c_style> a({3, 3, 3});
         auto r = a.mutable_unchecked();
-        if (r.ndim() != 3) throw std::domain_error("error: ndim != 3");
+        if (r.ndim() != 3)
+            throw std::domain_error("error: ndim != 3");
         for (py::ssize_t i = 0; i < r.shape(0); i++)
-        for (py::ssize_t j = 0; j < r.shape(1); j++)
-        for (py::ssize_t k = 0; k < r.shape(2); k++)
-            r(i, j, k) = start++;
+            for (py::ssize_t j = 0; j < r.shape(1); j++)
+                for (py::ssize_t k = 0; k < r.shape(2); k++)
+                    r(i, j, k) = start++;
         return a;
     });
     sm.def("proxy_auxiliaries2_dyn", [](py::array_t<double> a) {
         return auxiliaries(a.unchecked(), a.mutable_unchecked());
     });
 
-    sm.def("array_auxiliaries2", [](py::array_t<double> a) {
-        return auxiliaries(a, a);
-    });
+    sm.def("array_auxiliaries2", [](py::array_t<double> a) { return auxiliaries(a, a); });
 
     // test_array_failures
-    // Issue #785: Uninformative "Unknown internal error" exception when constructing array from empty object:
+    // Issue #785: Uninformative "Unknown internal error" exception when constructing array from
+    // empty object:
     sm.def("array_fail_test", []() { return py::array(py::object()); });
     sm.def("array_t_fail_test", []() { return py::array_t<double>(py::object()); });
     // Make sure the error from numpy is being passed through:
-    sm.def("array_fail_test_negative_size", []() { int c = 0; return py::array(-1, &c); });
+    sm.def("array_fail_test_negative_size", []() {
+        int c = 0;
+        return py::array(-1, &c);
+    });
 
     // test_initializer_list
     // Issue (unnumbered; reported in #788): regression: initializer lists can be ambiguous
-    sm.def("array_initializer_list1", []() { return py::array_t<float>(1); }); // { 1 } also works, but clang warns about it
-    sm.def("array_initializer_list2", []() { return py::array_t<float>({ 1, 2 }); });
-    sm.def("array_initializer_list3", []() { return py::array_t<float>({ 1, 2, 3 }); });
-    sm.def("array_initializer_list4", []() { return py::array_t<float>({ 1, 2, 3, 4 }); });
+    sm.def("array_initializer_list1",
+           []() { return py::array_t<float>(1); }); // { 1 } also works, but clang warns about it
+    sm.def("array_initializer_list2", []() { return py::array_t<float>({1, 2}); });
+    sm.def("array_initializer_list3", []() { return py::array_t<float>({1, 2, 3}); });
+    sm.def("array_initializer_list4", []() { return py::array_t<float>({1, 2, 3, 4}); });
 
     // test_array_resize
     // reshape array to 2D without changing size
     sm.def("array_reshape2", [](py::array_t<double> a) {
-        const auto dim_sz = (py::ssize_t)std::sqrt(a.size());
+        const auto dim_sz = (py::ssize_t) std::sqrt(a.size());
         if (dim_sz * dim_sz != a.size())
-            throw std::domain_error("array_reshape2: input array total size is not a squared integer");
+            throw std::domain_error(
+                "array_reshape2: input array total size is not a squared integer");
         a.resize({dim_sz, dim_sz});
     });
 
diff --git a/tests/test_numpy_dtypes.cpp b/tests/test_numpy_dtypes.cpp
index bf4f4cee74..1e04ef0fc8 100644
--- a/tests/test_numpy_dtypes.cpp
+++ b/tests/test_numpy_dtypes.cpp
@@ -7,13 +7,14 @@
   BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include <pybind11/numpy.h>
 
+#include "pybind11_tests.h"
+
 #ifdef __GNUC__
-#define PYBIND11_PACKED(cls) cls __attribute__((__packed__))
+#    define PYBIND11_PACKED(cls) cls __attribute__((__packed__))
 #else
-#define PYBIND11_PACKED(cls) __pragma(pack(push, 1)) cls __pragma(pack(pop))
+#    define PYBIND11_PACKED(cls) __pragma(pack(push, 1)) cls __pragma(pack(pop))
 #endif
 
 namespace py = pybind11;
@@ -25,7 +26,7 @@ struct SimpleStruct {
     long double ldbl_;
 };
 
-std::ostream& operator<<(std::ostream& os, const SimpleStruct& v) {
+std::ostream &operator<<(std::ostream &os, const SimpleStruct &v) {
     return os << "s:" << v.bool_ << "," << v.uint_ << "," << v.float_ << "," << v.ldbl_;
 }
 
@@ -43,7 +44,7 @@ PYBIND11_PACKED(struct PackedStruct {
     long double ldbl_;
 });
 
-std::ostream& operator<<(std::ostream& os, const PackedStruct& v) {
+std::ostream &operator<<(std::ostream &os, const PackedStruct &v) {
     return os << "p:" << v.bool_ << "," << v.uint_ << "," << v.float_ << "," << v.ldbl_;
 }
 
@@ -52,7 +53,7 @@ PYBIND11_PACKED(struct NestedStruct {
     PackedStruct b;
 });
 
-std::ostream& operator<<(std::ostream& os, const NestedStruct& v) {
+std::ostream &operator<<(std::ostream &os, const NestedStruct &v) {
     return os << "n:a=" << v.a << ";b=" << v.b;
 }
 
@@ -70,7 +71,7 @@ struct PartialNestedStruct {
     uint64_t dummy2;
 };
 
-struct UnboundStruct { };
+struct UnboundStruct {};
 
 struct StringStruct {
     char a[3];
@@ -82,7 +83,7 @@ struct ComplexStruct {
     std::complex<double> cdbl;
 };
 
-std::ostream& operator<<(std::ostream& os, const ComplexStruct& v) {
+std::ostream &operator<<(std::ostream &os, const ComplexStruct &v) {
     return os << "c:" << v.cflt << "," << v.cdbl;
 }
 
@@ -106,7 +107,7 @@ PYBIND11_PACKED(struct EnumStruct {
     E2 e2;
 });
 
-std::ostream& operator<<(std::ostream& os, const StringStruct& v) {
+std::ostream &operator<<(std::ostream &os, const StringStruct &v) {
     os << "a='";
     for (size_t i = 0; i < 3 && (v.a[i] != 0); i++)
         os << v.a[i];
@@ -116,7 +117,7 @@ std::ostream& operator<<(std::ostream& os, const StringStruct& v) {
     return os << "'";
 }
 
-std::ostream& operator<<(std::ostream& os, const ArrayStruct& v) {
+std::ostream &operator<<(std::ostream &os, const ArrayStruct &v) {
     os << "a={";
     for (int i = 0; i < 3; i++) {
         if (i > 0)
@@ -137,15 +138,14 @@ std::ostream& operator<<(std::ostream& os, const ArrayStruct& v) {
     return os << '}';
 }
 
-std::ostream& operator<<(std::ostream& os, const EnumStruct& v) {
+std::ostream &operator<<(std::ostream &os, const EnumStruct &v) {
     return os << "e1=" << (v.e1 == E1::A ? "A" : "B") << ",e2=" << (v.e2 == E2::X ? "X" : "Y");
 }
 
 template <typename T>
 py::array mkarray_via_buffer(size_t n) {
-    return py::array(py::buffer_info(nullptr, sizeof(T),
-                                     py::format_descriptor<T>::format(),
-                                     1, { n }, { sizeof(T) }));
+    return py::array(py::buffer_info(
+        nullptr, sizeof(T), py::format_descriptor<T>::format(), 1, {n}, {sizeof(T)}));
 }
 
 #define SET_TEST_VALS(s, i)                                                                       \
@@ -160,7 +160,7 @@ template <typename S>
 py::array_t<S, 0> create_recarray(size_t n) {
     auto arr = mkarray_via_buffer<S>(n);
     auto req = arr.request();
-    auto ptr = static_cast<S*>(req.ptr);
+    auto *ptr = static_cast<S *>(req.ptr);
     for (size_t i = 0; i < n; i++) {
         SET_TEST_VALS(ptr[i], i);
     }
@@ -170,7 +170,7 @@ py::array_t<S, 0> create_recarray(size_t n) {
 template <typename S>
 py::list print_recarray(py::array_t<S, 0> arr) {
     const auto req = arr.request();
-    const auto ptr = static_cast<S*>(req.ptr);
+    const auto *ptr = static_cast<S *>(req.ptr);
     auto l = py::list();
     for (py::ssize_t i = 0; i < req.size; i++) {
         std::stringstream ss;
@@ -183,12 +183,12 @@ py::list print_recarray(py::array_t<S, 0> arr) {
 py::array_t<int32_t, 0> test_array_ctors(int i) {
     using arr_t = py::array_t<int32_t, 0>;
 
-    std::vector<int32_t> data { 1, 2, 3, 4, 5, 6 };
-    std::vector<py::ssize_t> shape { 3, 2 };
-    std::vector<py::ssize_t> strides { 8, 4 };
+    std::vector<int32_t> data{1, 2, 3, 4, 5, 6};
+    std::vector<py::ssize_t> shape{3, 2};
+    std::vector<py::ssize_t> strides{8, 4};
 
-    auto ptr = data.data();
-    auto vptr = (void *) ptr;
+    auto *ptr = data.data();
+    auto *vptr = (void *) ptr;
     auto dtype = py::dtype("int32");
 
     py::buffer_info buf_ndim1(vptr, 4, "i", 6);
@@ -198,41 +198,68 @@ py::array_t<int32_t, 0> test_array_ctors(int i) {
 
     auto fill = [](py::array arr) {
         auto req = arr.request();
-        for (int i = 0; i < 6; i++) ((int32_t *) req.ptr)[i] = i + 1;
+        for (int i = 0; i < 6; i++)
+            ((int32_t *) req.ptr)[i] = i + 1;
         return arr;
     };
 
     switch (i) {
-    // shape: (3, 2)
-    case 10: return arr_t(shape, strides, ptr);
-    case 11: return py::array(shape, strides, ptr);
-    case 12: return py::array(dtype, shape, strides, vptr);
-    case 13: return arr_t(shape, ptr);
-    case 14: return py::array(shape, ptr);
-    case 15: return py::array(dtype, shape, vptr);
-    case 16: return arr_t(buf_ndim2);
-    case 17: return py::array(buf_ndim2);
-    // shape: (3, 2) - post-fill
-    case 20: return fill(arr_t(shape, strides));
-    case 21: return py::array(shape, strides, ptr); // can't have nullptr due to templated ctor
-    case 22: return fill(py::array(dtype, shape, strides));
-    case 23: return fill(arr_t(shape));
-    case 24: return py::array(shape, ptr); // can't have nullptr due to templated ctor
-    case 25: return fill(py::array(dtype, shape));
-    case 26: return fill(arr_t(buf_ndim2_null));
-    case 27: return fill(py::array(buf_ndim2_null));
-    // shape: (6, )
-    case 30: return arr_t(6, ptr);
-    case 31: return py::array(6, ptr);
-    case 32: return py::array(dtype, 6, vptr);
-    case 33: return arr_t(buf_ndim1);
-    case 34: return py::array(buf_ndim1);
-    // shape: (6, )
-    case 40: return fill(arr_t(6));
-    case 41: return py::array(6, ptr);  // can't have nullptr due to templated ctor
-    case 42: return fill(py::array(dtype, 6));
-    case 43: return fill(arr_t(buf_ndim1_null));
-    case 44: return fill(py::array(buf_ndim1_null));
+        // shape: (3, 2)
+        case 10:
+            return arr_t(shape, strides, ptr);
+        case 11:
+            return py::array(shape, strides, ptr);
+        case 12:
+            return py::array(dtype, shape, strides, vptr);
+        case 13:
+            return arr_t(shape, ptr);
+        case 14:
+            return py::array(shape, ptr);
+        case 15:
+            return py::array(dtype, shape, vptr);
+        case 16:
+            return arr_t(buf_ndim2);
+        case 17:
+            return py::array(buf_ndim2);
+        // shape: (3, 2) - post-fill
+        case 20:
+            return fill(arr_t(shape, strides));
+        case 21:
+            return py::array(shape, strides, ptr); // can't have nullptr due to templated ctor
+        case 22:
+            return fill(py::array(dtype, shape, strides));
+        case 23:
+            return fill(arr_t(shape));
+        case 24:
+            return py::array(shape, ptr); // can't have nullptr due to templated ctor
+        case 25:
+            return fill(py::array(dtype, shape));
+        case 26:
+            return fill(arr_t(buf_ndim2_null));
+        case 27:
+            return fill(py::array(buf_ndim2_null));
+        // shape: (6, )
+        case 30:
+            return arr_t(6, ptr);
+        case 31:
+            return py::array(6, ptr);
+        case 32:
+            return py::array(dtype, 6, vptr);
+        case 33:
+            return arr_t(buf_ndim1);
+        case 34:
+            return py::array(buf_ndim1);
+        // shape: (6, )
+        case 40:
+            return fill(arr_t(6));
+        case 41:
+            return py::array(6, ptr); // can't have nullptr due to templated ctor
+        case 42:
+            return fill(py::array(dtype, 6));
+        case 43:
+            return fill(arr_t(buf_ndim1_null));
+        case 44:
+            return fill(py::array(buf_ndim1_null));
     }
     return arr_t();
 }
@@ -244,9 +271,15 @@ py::list test_dtype_ctors() {
     list.append(py::dtype::from_args(py::str("bool")));
     py::list names, offsets, formats;
     py::dict dict;
-    names.append(py::str("a")); names.append(py::str("b")); dict["names"] = names;
-    offsets.append(py::int_(1)); offsets.append(py::int_(10)); dict["offsets"] = offsets;
-    formats.append(py::dtype("int32")); formats.append(py::dtype("float64")); dict["formats"] = formats;
+    names.append(py::str("a"));
+    names.append(py::str("b"));
+    dict["names"] = names;
+    offsets.append(py::int_(1));
+    offsets.append(py::int_(10));
+    dict["offsets"] = offsets;
+    formats.append(py::dtype("int32"));
+    formats.append(py::dtype("float64"));
+    dict["formats"] = formats;
     dict["itemsize"] = py::int_(20);
     list.append(py::dtype::from_args(dict));
     list.append(py::dtype(names, formats, offsets, 20));
@@ -259,8 +292,11 @@ struct A {};
 struct B {};
 
 TEST_SUBMODULE(numpy_dtypes, m) {
-    try { py::module_::import("numpy"); }
-    catch (...) { return; }
+    try {
+        py::module_::import("numpy");
+    } catch (...) {
+        return;
+    }
 
     // typeinfo may be registered before the dtype descriptor for scalar casts to work...
     py::class_<SimpleStruct>(m, "SimpleStruct")
@@ -278,11 +314,10 @@ TEST_SUBMODULE(numpy_dtypes, m) {
             if (py::len(tup) != 4) {
                 throw py::cast_error("Invalid size");
             }
-            return SimpleStruct{
-                tup[0].cast<bool>(),
-                tup[1].cast<uint32_t>(),
-                tup[2].cast<float>(),
-                tup[3].cast<long double>()};
+            return SimpleStruct{tup[0].cast<bool>(),
+                                tup[1].cast<uint32_t>(),
+                                tup[2].cast<float>(),
+                                tup[3].cast<long double>()};
         });
 
     PYBIND11_NUMPY_DTYPE(SimpleStruct, bool_, uint_, float_, ldbl_);
@@ -303,17 +338,14 @@ TEST_SUBMODULE(numpy_dtypes, m) {
 
     // If uncommented, this should produce a static_assert failure telling the user that the struct
     // is not a POD type
-//    struct NotPOD { std::string v; NotPOD() : v("hi") {}; };
-//    PYBIND11_NUMPY_DTYPE(NotPOD, v);
+    //    struct NotPOD { std::string v; NotPOD() : v("hi") {}; };
+    //    PYBIND11_NUMPY_DTYPE(NotPOD, v);
 
     // Check that dtypes can be registered programmatically, both from
     // initializer lists of field descriptors and from other containers.
-    py::detail::npy_format_descriptor<A>::register_dtype(
-        {}
-    );
+    py::detail::npy_format_descriptor<A>::register_dtype({});
     py::detail::npy_format_descriptor<B>::register_dtype(
-        std::vector<py::detail::field_descriptor>{}
-    );
+        std::vector<py::detail::field_descriptor>{});
 
     // test_recarray, test_scalar_conversion
     m.def("create_rec_simple", &create_recarray<SimpleStruct>);
@@ -321,7 +353,7 @@ TEST_SUBMODULE(numpy_dtypes, m) {
     m.def("create_rec_nested", [](size_t n) { // test_signature
         py::array_t<NestedStruct, 0> arr = mkarray_via_buffer<NestedStruct>(n);
         auto req = arr.request();
-        auto ptr = static_cast<NestedStruct*>(req.ptr);
+        auto *ptr = static_cast<NestedStruct *>(req.ptr);
         for (size_t i = 0; i < n; i++) {
             SET_TEST_VALS(ptr[i].a, i);
             SET_TEST_VALS(ptr[i].b, i + 1);
@@ -332,7 +364,7 @@ TEST_SUBMODULE(numpy_dtypes, m) {
     m.def("create_rec_partial_nested", [](size_t n) {
         py::array_t<PartialNestedStruct, 0> arr = mkarray_via_buffer<PartialNestedStruct>(n);
         auto req = arr.request();
-        auto ptr = static_cast<PartialNestedStruct*>(req.ptr);
+        auto *ptr = static_cast<PartialNestedStruct *>(req.ptr);
         for (size_t i = 0; i < n; i++) {
             SET_TEST_VALS(ptr[i].a, i);
         }
@@ -346,17 +378,15 @@ TEST_SUBMODULE(numpy_dtypes, m) {
     m.def("get_format_unbound", []() { return py::format_descriptor<UnboundStruct>::format(); });
     m.def("print_format_descriptors", []() {
         py::list l;
-        for (const auto &fmt : {
-            py::format_descriptor<SimpleStruct>::format(),
-            py::format_descriptor<PackedStruct>::format(),
-            py::format_descriptor<NestedStruct>::format(),
-            py::format_descriptor<PartialStruct>::format(),
-            py::format_descriptor<PartialNestedStruct>::format(),
-            py::format_descriptor<StringStruct>::format(),
-            py::format_descriptor<ArrayStruct>::format(),
-            py::format_descriptor<EnumStruct>::format(),
-            py::format_descriptor<ComplexStruct>::format()
-        }) {
+        for (const auto &fmt : {py::format_descriptor<SimpleStruct>::format(),
+                                py::format_descriptor<PackedStruct>::format(),
+                                py::format_descriptor<NestedStruct>::format(),
+                                py::format_descriptor<PartialStruct>::format(),
+                                py::format_descriptor<PartialNestedStruct>::format(),
+                                py::format_descriptor<StringStruct>::format(),
+                                py::format_descriptor<ArrayStruct>::format(),
+                                py::format_descriptor<EnumStruct>::format(),
+                                py::format_descriptor<ComplexStruct>::format()}) {
             l.append(py::cast(fmt));
         }
         return l;
@@ -364,40 +394,35 @@ TEST_SUBMODULE(numpy_dtypes, m) {
 
     // test_dtype
     std::vector<const char *> dtype_names{
-        "byte", "short", "intc", "int_", "longlong",
-        "ubyte", "ushort", "uintc", "uint", "ulonglong",
-        "half", "single", "double", "longdouble",
-        "csingle", "cdouble", "clongdouble",
-        "bool_", "datetime64", "timedelta64", "object_"
-    };
+        "byte",    "short",   "intc",        "int_",  "longlong",   "ubyte",       "ushort",
+        "uintc",   "uint",    "ulonglong",   "half",  "single",     "double",      "longdouble",
+        "csingle", "cdouble", "clongdouble", "bool_", "datetime64", "timedelta64", "object_"};
 
     m.def("print_dtypes", []() {
         py::list l;
-        for (const py::handle &d : {
-            py::dtype::of<SimpleStruct>(),
-            py::dtype::of<PackedStruct>(),
-            py::dtype::of<NestedStruct>(),
-            py::dtype::of<PartialStruct>(),
-            py::dtype::of<PartialNestedStruct>(),
-            py::dtype::of<StringStruct>(),
-            py::dtype::of<ArrayStruct>(),
-            py::dtype::of<EnumStruct>(),
-            py::dtype::of<StructWithUglyNames>(),
-            py::dtype::of<ComplexStruct>()
-        })
+        for (const py::handle &d : {py::dtype::of<SimpleStruct>(),
+                                    py::dtype::of<PackedStruct>(),
+                                    py::dtype::of<NestedStruct>(),
+                                    py::dtype::of<PartialStruct>(),
+                                    py::dtype::of<PartialNestedStruct>(),
+                                    py::dtype::of<StringStruct>(),
+                                    py::dtype::of<ArrayStruct>(),
+                                    py::dtype::of<EnumStruct>(),
+                                    py::dtype::of<StructWithUglyNames>(),
+                                    py::dtype::of<ComplexStruct>()})
             l.append(py::str(d));
         return l;
     });
     m.def("test_dtype_ctors", &test_dtype_ctors);
     m.def("test_dtype_kind", [dtype_names]() {
         py::list list;
-        for (auto& dt_name : dtype_names)
+        for (const auto &dt_name : dtype_names)
             list.append(py::dtype(dt_name).kind());
         return list;
     });
     m.def("test_dtype_char_", [dtype_names]() {
         py::list list;
-        for (auto& dt_name : dtype_names)
+        for (const auto &dt_name : dtype_names)
             list.append(py::dtype(dt_name).char_());
         return list;
     });
@@ -405,9 +430,12 @@ TEST_SUBMODULE(numpy_dtypes, m) {
         py::list list;
         auto dt1 = py::dtype::of<int32_t>();
         auto dt2 = py::dtype::of<SimpleStruct>();
-        list.append(dt1); list.append(dt2);
-        list.append(py::bool_(dt1.has_fields())); list.append(py::bool_(dt2.has_fields()));
-        list.append(py::int_(dt1.itemsize())); list.append(py::int_(dt2.itemsize()));
+        list.append(dt1);
+        list.append(dt2);
+        list.append(py::bool_(dt1.has_fields()));
+        list.append(py::bool_(dt2.has_fields()));
+        list.append(py::int_(dt1.itemsize()));
+        list.append(py::int_(dt2.itemsize()));
         return list;
     });
     struct TrailingPaddingStruct {
@@ -422,17 +450,23 @@ TEST_SUBMODULE(numpy_dtypes, m) {
         py::array_t<StringStruct, 0> arr = mkarray_via_buffer<StringStruct>(non_empty ? 4 : 0);
         if (non_empty) {
             auto req = arr.request();
-            auto ptr = static_cast<StringStruct*>(req.ptr);
+            auto *ptr = static_cast<StringStruct *>(req.ptr);
             for (py::ssize_t i = 0; i < req.size * req.itemsize; i++)
-                static_cast<char*>(req.ptr)[i] = 0;
-            ptr[1].a[0] = 'a'; ptr[1].b[0] = 'a';
-            ptr[2].a[0] = 'a'; ptr[2].b[0] = 'a';
-            ptr[3].a[0] = 'a'; ptr[3].b[0] = 'a';
-
-            ptr[2].a[1] = 'b'; ptr[2].b[1] = 'b';
-            ptr[3].a[1] = 'b'; ptr[3].b[1] = 'b';
-
-            ptr[3].a[2] = 'c'; ptr[3].b[2] = 'c';
+                static_cast<char *>(req.ptr)[i] = 0;
+            ptr[1].a[0] = 'a';
+            ptr[1].b[0] = 'a';
+            ptr[2].a[0] = 'a';
+            ptr[2].b[0] = 'a';
+            ptr[3].a[0] = 'a';
+            ptr[3].b[0] = 'a';
+
+            ptr[2].a[1] = 'b';
+            ptr[2].b[1] = 'b';
+            ptr[3].a[1] = 'b';
+            ptr[3].b[1] = 'b';
+
+            ptr[3].a[2] = 'c';
+            ptr[3].b[2] = 'c';
         }
         return arr;
     });
@@ -441,7 +475,7 @@ TEST_SUBMODULE(numpy_dtypes, m) {
     // test_array_array
     m.def("create_array_array", [](size_t n) {
         py::array_t<ArrayStruct, 0> arr = mkarray_via_buffer<ArrayStruct>(n);
-        auto ptr = (ArrayStruct *) arr.mutable_data();
+        auto *ptr = (ArrayStruct *) arr.mutable_data();
         for (size_t i = 0; i < n; i++) {
             for (size_t j = 0; j < 3; j++)
                 for (size_t k = 0; k < 4; k++)
@@ -461,7 +495,7 @@ TEST_SUBMODULE(numpy_dtypes, m) {
     // test_enum_array
     m.def("create_enum_array", [](size_t n) {
         py::array_t<EnumStruct, 0> arr = mkarray_via_buffer<EnumStruct>(n);
-        auto ptr = (EnumStruct *) arr.mutable_data();
+        auto *ptr = (EnumStruct *) arr.mutable_data();
         for (size_t i = 0; i < n; i++) {
             ptr[i].e1 = static_cast<E1>(-1 + ((int) i % 2) * 2);
             ptr[i].e2 = static_cast<E2>(1 + (i % 2));
@@ -473,7 +507,7 @@ TEST_SUBMODULE(numpy_dtypes, m) {
     // test_complex_array
     m.def("create_complex_array", [](size_t n) {
         py::array_t<ComplexStruct, 0> arr = mkarray_via_buffer<ComplexStruct>(n);
-        auto ptr = (ComplexStruct *) arr.mutable_data();
+        auto *ptr = (ComplexStruct *) arr.mutable_data();
         for (size_t i = 0; i < n; i++) {
             ptr[i].cflt.real(float(i));
             ptr[i].cflt.imag(float(i) + 0.25f);
@@ -496,14 +530,19 @@ TEST_SUBMODULE(numpy_dtypes, m) {
     PYBIND11_NUMPY_DTYPE(CompareStruct, x, y, z);
     m.def("compare_buffer_info", []() {
         py::list list;
-        list.append(py::bool_(py::detail::compare_buffer_info<float>::compare(py::buffer_info(nullptr, sizeof(float), "f", 1))));
-        list.append(py::bool_(py::detail::compare_buffer_info<unsigned>::compare(py::buffer_info(nullptr, sizeof(int), "I", 1))));
-        list.append(py::bool_(py::detail::compare_buffer_info<long>::compare(py::buffer_info(nullptr, sizeof(long), "l", 1))));
-        list.append(py::bool_(py::detail::compare_buffer_info<long>::compare(py::buffer_info(nullptr, sizeof(long), sizeof(long) == sizeof(int) ? "i" : "q", 1))));
-        list.append(py::bool_(py::detail::compare_buffer_info<CompareStruct>::compare(py::buffer_info(nullptr, sizeof(CompareStruct), "T{?:x:3xI:y:f:z:}", 1))));
+        list.append(py::bool_(py::detail::compare_buffer_info<float>::compare(
+            py::buffer_info(nullptr, sizeof(float), "f", 1))));
+        list.append(py::bool_(py::detail::compare_buffer_info<unsigned>::compare(
+            py::buffer_info(nullptr, sizeof(int), "I", 1))));
+        list.append(py::bool_(py::detail::compare_buffer_info<long>::compare(
+            py::buffer_info(nullptr, sizeof(long), "l", 1))));
+        list.append(py::bool_(py::detail::compare_buffer_info<long>::compare(
+            py::buffer_info(nullptr, sizeof(long), sizeof(long) == sizeof(int) ? "i" : "q", 1))));
+        list.append(py::bool_(py::detail::compare_buffer_info<CompareStruct>::compare(
+            py::buffer_info(nullptr, sizeof(CompareStruct), "T{?:x:3xI:y:f:z:}", 1))));
         return list;
     });
-    m.def("buffer_to_dtype", [](py::buffer& buf) { return py::dtype(buf.request()); });
+    m.def("buffer_to_dtype", [](py::buffer &buf) { return py::dtype(buf.request()); });
 
     // test_scalar_conversion
     auto f_simple = [](SimpleStruct s) { return s.uint_ * 10; };
@@ -517,7 +556,8 @@ TEST_SUBMODULE(numpy_dtypes, m) {
     m.def("f_simple_pass_thru_vectorized", py::vectorize(f_simple_pass_thru));
 
     // test_register_dtype
-    m.def("register_dtype", []() { PYBIND11_NUMPY_DTYPE(SimpleStruct, bool_, uint_, float_, ldbl_); });
+    m.def("register_dtype",
+          []() { PYBIND11_NUMPY_DTYPE(SimpleStruct, bool_, uint_, float_, ldbl_); });
 
     // test_str_leak
     m.def("dtype_wrapper", [](py::object d) { return py::dtype::from_args(std::move(d)); });
diff --git a/tests/test_numpy_vectorize.cpp b/tests/test_numpy_vectorize.cpp
index eb5281fb1d..eab08ec0a6 100644
--- a/tests/test_numpy_vectorize.cpp
+++ b/tests/test_numpy_vectorize.cpp
@@ -8,38 +8,43 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include <pybind11/numpy.h>
 
+#include "pybind11_tests.h"
+
 #include <utility>
 
 double my_func(int x, float y, double z) {
     py::print("my_func(x:int={}, y:float={:.0f}, z:float={:.0f})"_s.format(x, y, z));
-    return (float) x*y*z;
+    return (float) x * y * z;
 }
 
 TEST_SUBMODULE(numpy_vectorize, m) {
-    try { py::module_::import("numpy"); }
-    catch (...) { return; }
+    try {
+        py::module_::import("numpy");
+    } catch (...) {
+        return;
+    }
 
     // test_vectorize, test_docs, test_array_collapse
     // Vectorize all arguments of a function (though non-vector arguments are also allowed)
     m.def("vectorized_func", py::vectorize(my_func));
 
-    // Vectorize a lambda function with a capture object (e.g. to exclude some arguments from the vectorization)
+    // Vectorize a lambda function with a capture object (e.g. to exclude some arguments from the
+    // vectorization)
     m.def("vectorized_func2", [](py::array_t<int> x, py::array_t<float> y, float z) {
         return py::vectorize([z](int x, float y) { return my_func(x, y, z); })(std::move(x),
                                                                                std::move(y));
     });
 
     // Vectorize a complex-valued function
-    m.def("vectorized_func3", py::vectorize(
-        [](std::complex<double> c) { return c * std::complex<double>(2.f); }
-    ));
+    m.def("vectorized_func3",
+          py::vectorize([](std::complex<double> c) { return c * std::complex<double>(2.f); }));
 
     // test_type_selection
     // NumPy function which only accepts specific data types
-    // A lot of these no lints could be replaced with const refs, and probably should at some point.
+    // A lot of these no lints could be replaced with const refs, and probably should at some
+    // point.
     m.def("selective_func",
           [](const py::array_t<int, py::array::c_style> &) { return "Int branch taken."; });
     m.def("selective_func",
@@ -49,8 +54,8 @@ TEST_SUBMODULE(numpy_vectorize, m) {
     });
 
     // test_passthrough_arguments
-    // Passthrough test: references and non-pod types should be automatically passed through (in the
-    // function definition below, only `b`, `d`, and `g` are vectorized):
+    // Passthrough test: references and non-pod types should be automatically passed through (in
+    // the function definition below, only `b`, `d`, and `g` are vectorized):
     struct NonPODClass {
         explicit NonPODClass(int v) : value{v} {}
         int value;
@@ -76,8 +81,7 @@ TEST_SUBMODULE(numpy_vectorize, m) {
         int value = 0;
     };
     py::class_<VectorizeTestClass> vtc(m, "VectorizeTestClass");
-    vtc .def(py::init<int>())
-        .def_readwrite("value", &VectorizeTestClass::value);
+    vtc.def(py::init<int>()).def_readwrite("value", &VectorizeTestClass::value);
 
     // Automatic vectorizing of methods
     vtc.def("method", py::vectorize(&VectorizeTestClass::method));
@@ -99,5 +103,5 @@ TEST_SUBMODULE(numpy_vectorize, m) {
               return py::detail::broadcast(buffers, ndim, shape);
           });
 
-    m.def("add_to", py::vectorize([](NonPODClass& x, int a) { x.value += a; }));
+    m.def("add_to", py::vectorize([](NonPODClass &x, int a) { x.value += a; }));
 }
diff --git a/tests/test_opaque_types.cpp b/tests/test_opaque_types.cpp
index 804de6d4ff..28b49c9315 100644
--- a/tests/test_opaque_types.cpp
+++ b/tests/test_opaque_types.cpp
@@ -7,8 +7,10 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include <pybind11/stl.h>
+
+#include "pybind11_tests.h"
+
 #include <vector>
 
 // IMPORTANT: Disable internal pybind11 translation mechanisms for STL data structures
@@ -26,12 +28,13 @@ TEST_SUBMODULE(opaque_types, m) {
         .def(py::init<>())
         .def("pop_back", &StringList::pop_back)
         /* There are multiple versions of push_back(), etc. Select the right ones. */
-        .def("push_back", (void (StringList::*)(const std::string &)) &StringList::push_back)
-        .def("back", (std::string &(StringList::*)()) &StringList::back)
+        .def("push_back", (void(StringList::*)(const std::string &)) & StringList::push_back)
+        .def("back", (std::string & (StringList::*) ()) & StringList::back)
         .def("__len__", [](const StringList &v) { return v.size(); })
-        .def("__iter__", [](StringList &v) {
-           return py::make_iterator(v.begin(), v.end());
-        }, py::keep_alive<0, 1>());
+        .def(
+            "__iter__",
+            [](StringList &v) { return py::make_iterator(v.begin(), v.end()); },
+            py::keep_alive<0, 1>());
 
     class ClassWithSTLVecProperty {
     public:
diff --git a/tests/test_operator_overloading.cpp b/tests/test_operator_overloading.cpp
index ffa059d5b5..a4b895a897 100644
--- a/tests/test_operator_overloading.cpp
+++ b/tests/test_operator_overloading.cpp
@@ -7,11 +7,13 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
+#include <pybind11/operators.h>
+#include <pybind11/stl.h>
+
 #include "constructor_stats.h"
 #include "pybind11_tests.h"
+
 #include <functional>
-#include <pybind11/operators.h>
-#include <pybind11/stl.h>
 
 class Vector2 {
 public:
@@ -21,17 +23,24 @@ class Vector2 {
         print_move_created(this);
         v.x = v.y = 0;
     }
-    Vector2 &operator=(const Vector2 &v) { x = v.x; y = v.y; print_copy_assigned(this); return *this; }
+    Vector2 &operator=(const Vector2 &v) {
+        x = v.x;
+        y = v.y;
+        print_copy_assigned(this);
+        return *this;
+    }
     Vector2 &operator=(Vector2 &&v) noexcept {
-        x   = v.x;
-        y   = v.y;
+        x = v.x;
+        y = v.y;
         v.x = v.y = 0;
         print_move_assigned(this);
         return *this;
     }
     ~Vector2() { print_destroyed(this); }
 
-    std::string toString() const { return "[" + std::to_string(x) + ", " + std::to_string(y) + "]"; }
+    std::string toString() const {
+        return "[" + std::to_string(x) + ", " + std::to_string(y) + "]";
+    }
 
     Vector2 operator-() const { return Vector2(-x, -y); }
     Vector2 operator+(const Vector2 &v) const { return Vector2(x + v.x, y + v.y); }
@@ -42,30 +51,51 @@ class Vector2 {
     Vector2 operator/(float value) const { return Vector2(x / value, y / value); }
     Vector2 operator*(const Vector2 &v) const { return Vector2(x * v.x, y * v.y); }
     Vector2 operator/(const Vector2 &v) const { return Vector2(x / v.x, y / v.y); }
-    Vector2& operator+=(const Vector2 &v) { x += v.x; y += v.y; return *this; }
-    Vector2& operator-=(const Vector2 &v) { x -= v.x; y -= v.y; return *this; }
-    Vector2& operator*=(float v) { x *= v; y *= v; return *this; }
-    Vector2& operator/=(float v) { x /= v; y /= v; return *this; }
-    Vector2& operator*=(const Vector2 &v) { x *= v.x; y *= v.y; return *this; }
-    Vector2& operator/=(const Vector2 &v) { x /= v.x; y /= v.y; return *this; }
+    Vector2 &operator+=(const Vector2 &v) {
+        x += v.x;
+        y += v.y;
+        return *this;
+    }
+    Vector2 &operator-=(const Vector2 &v) {
+        x -= v.x;
+        y -= v.y;
+        return *this;
+    }
+    Vector2 &operator*=(float v) {
+        x *= v;
+        y *= v;
+        return *this;
+    }
+    Vector2 &operator/=(float v) {
+        x /= v;
+        y /= v;
+        return *this;
+    }
+    Vector2 &operator*=(const Vector2 &v) {
+        x *= v.x;
+        y *= v.y;
+        return *this;
+    }
+    Vector2 &operator/=(const Vector2 &v) {
+        x /= v.x;
+        y /= v.y;
+        return *this;
+    }
 
     friend Vector2 operator+(float f, const Vector2 &v) { return Vector2(f + v.x, f + v.y); }
     friend Vector2 operator-(float f, const Vector2 &v) { return Vector2(f - v.x, f - v.y); }
     friend Vector2 operator*(float f, const Vector2 &v) { return Vector2(f * v.x, f * v.y); }
     friend Vector2 operator/(float f, const Vector2 &v) { return Vector2(f / v.x, f / v.y); }
 
-    bool operator==(const Vector2 &v) const {
-        return x == v.x && y == v.y;
-    }
-    bool operator!=(const Vector2 &v) const {
-        return x != v.x || y != v.y;
-    }
+    bool operator==(const Vector2 &v) const { return x == v.x && y == v.y; }
+    bool operator!=(const Vector2 &v) const { return x != v.x || y != v.y; }
+
 private:
     float x, y;
 };
 
-class C1 { };
-class C2 { };
+class C1 {};
+class C2 {};
 
 int operator+(const C1 &, const C1 &) { return 11; }
 int operator+(const C2 &, const C2 &) { return 22; }
@@ -84,43 +114,41 @@ bool operator==(const HashMe &lhs, const HashMe &rhs) { return lhs.member == rhs
 // namespace instead, per this recommendation:
 // https://en.cppreference.com/w/cpp/language/extending_std#Adding_template_specializations
 namespace std {
-    template<>
-    struct hash<Vector2> {
-        // Not a good hash function, but easy to test
-        size_t operator()(const Vector2 &) { return 4; }
-    };
+template <>
+struct hash<Vector2> {
+    // Not a good hash function, but easy to test
+    size_t operator()(const Vector2 &) { return 4; }
+};
 
-    // HashMe has a hash function in C++ but no `__hash__` for Python.
-    template <>
-    struct hash<HashMe> {
-        std::size_t operator()(const HashMe &selector) const {
-            return std::hash<std::string>()(selector.member);
-        }
-    };
+// HashMe has a hash function in C++ but no `__hash__` for Python.
+template <>
+struct hash<HashMe> {
+    std::size_t operator()(const HashMe &selector) const {
+        return std::hash<std::string>()(selector.member);
+    }
+};
 } // namespace std
 
 // Not a good abs function, but easy to test.
-std::string abs(const Vector2&) {
-    return "abs(Vector2)";
-}
+std::string abs(const Vector2 &) { return "abs(Vector2)"; }
 
 // MSVC & Intel warns about unknown pragmas, and warnings are errors.
 #if !defined(_MSC_VER) && !defined(__INTEL_COMPILER)
-  #pragma GCC diagnostic push
-  // clang 7.0.0 and Apple LLVM 10.0.1 introduce `-Wself-assign-overloaded` to
-  // `-Wall`, which is used here for overloading (e.g. `py::self += py::self `).
-  // Here, we suppress the warning using `#pragma diagnostic`.
-  // Taken from: https://github.com/RobotLocomotion/drake/commit/aaf84b46
-  // TODO(eric): This could be resolved using a function / functor (e.g. `py::self()`).
-  #if defined(__APPLE__) && defined(__clang__)
-    #if (__clang_major__ >= 10)
-      #pragma GCC diagnostic ignored "-Wself-assign-overloaded"
-    #endif
-  #elif defined(__clang__)
-    #if (__clang_major__ >= 7)
-      #pragma GCC diagnostic ignored "-Wself-assign-overloaded"
-    #endif
-  #endif
+#    pragma GCC diagnostic push
+// clang 7.0.0 and Apple LLVM 10.0.1 introduce `-Wself-assign-overloaded` to
+// `-Wall`, which is used here for overloading (e.g. `py::self += py::self `).
+// Here, we suppress the warning using `#pragma diagnostic`.
+// Taken from: https://github.com/RobotLocomotion/drake/commit/aaf84b46
+// TODO(eric): This could be resolved using a function / functor (e.g. `py::self()`).
+#    if defined(__APPLE__) && defined(__clang__)
+#        if (__clang_major__ >= 10)
+#            pragma GCC diagnostic ignored "-Wself-assign-overloaded"
+#        endif
+#    elif defined(__clang__)
+#        if (__clang_major__ >= 7)
+#            pragma GCC diagnostic ignored "-Wself-assign-overloaded"
+#        endif
+#    endif
 #endif
 
 TEST_SUBMODULE(operators, m) {
@@ -154,46 +182,52 @@ TEST_SUBMODULE(operators, m) {
         .def(py::hash(py::self))
         // N.B. See warning about usage of `py::detail::abs(py::self)` in
         // `operators.h`.
-        .def("__abs__", [](const Vector2& v) { return abs(v); })
-        ;
+        .def("__abs__", [](const Vector2 &v) { return abs(v); });
 
     m.attr("Vector") = m.attr("Vector2");
 
     // test_operators_notimplemented
     // #393: need to return NotSupported to ensure correct arithmetic operator behavior
-    py::class_<C1>(m, "C1")
-        .def(py::init<>())
-        .def(py::self + py::self);
+    py::class_<C1>(m, "C1").def(py::init<>()).def(py::self + py::self);
 
     py::class_<C2>(m, "C2")
         .def(py::init<>())
         .def(py::self + py::self)
-        .def("__add__", [](const C2& c2, const C1& c1) { return c2 + c1; })
-        .def("__radd__", [](const C2& c2, const C1& c1) { return c1 + c2; });
+        .def("__add__", [](const C2 &c2, const C1 &c1) { return c2 + c1; })
+        .def("__radd__", [](const C2 &c2, const C1 &c1) { return c1 + c2; });
 
     // test_nested
     // #328: first member in a class can't be used in operators
-    struct NestABase { int value = -2; };
+    struct NestABase {
+        int value = -2;
+    };
     py::class_<NestABase>(m, "NestABase")
         .def(py::init<>())
         .def_readwrite("value", &NestABase::value);
 
     struct NestA : NestABase {
         int value = 3;
-        NestA& operator+=(int i) { value += i; return *this; }
+        NestA &operator+=(int i) {
+            value += i;
+            return *this;
+        }
     };
     py::class_<NestA>(m, "NestA")
         .def(py::init<>())
         .def(py::self += int())
-        .def("as_base", [](NestA &a) -> NestABase& {
-            return (NestABase&) a;
-        }, py::return_value_policy::reference_internal);
+        .def(
+            "as_base",
+            [](NestA &a) -> NestABase & { return (NestABase &) a; },
+            py::return_value_policy::reference_internal);
     m.def("get_NestA", [](const NestA &a) { return a.value; });
 
     struct NestB {
         NestA a;
         int value = 4;
-        NestB& operator-=(int i) { value -= i; return *this; }
+        NestB &operator-=(int i) {
+            value -= i;
+            return *this;
+        }
     };
     py::class_<NestB>(m, "NestB")
         .def(py::init<>())
@@ -204,7 +238,10 @@ TEST_SUBMODULE(operators, m) {
     struct NestC {
         NestB b;
         int value = 5;
-        NestC& operator*=(int i) { value *= i; return *this; }
+        NestC &operator*=(int i) {
+            value *= i;
+            return *this;
+        }
     };
     py::class_<NestC>(m, "NestC")
         .def(py::init<>())
@@ -212,16 +249,15 @@ TEST_SUBMODULE(operators, m) {
         .def_readwrite("b", &NestC::b);
     m.def("get_NestC", [](const NestC &c) { return c.value; });
 
-
     // test_overriding_eq_reset_hash
     // #2191 Overriding __eq__ should set __hash__ to None
     struct Comparable {
         int value;
-        bool operator==(const Comparable& rhs) const {return value == rhs.value;}
+        bool operator==(const Comparable &rhs) const { return value == rhs.value; }
     };
 
     struct Hashable : Comparable {
-        explicit Hashable(int value): Comparable{value}{};
+        explicit Hashable(int value) : Comparable{value} {};
         size_t hash() const { return static_cast<size_t>(value); }
     };
 
@@ -229,9 +265,7 @@ TEST_SUBMODULE(operators, m) {
         using Hashable::Hashable;
     };
 
-    py::class_<Comparable>(m, "Comparable")
-        .def(py::init<int>())
-        .def(py::self == py::self);
+    py::class_<Comparable>(m, "Comparable").def(py::init<int>()).def(py::self == py::self);
 
     py::class_<Hashable>(m, "Hashable")
         .def(py::init<int>())
@@ -250,5 +284,5 @@ TEST_SUBMODULE(operators, m) {
     m.def("get_unhashable_HashMe_set", []() { return std::unordered_set<HashMe>{{"one"}}; });
 }
 #if !defined(_MSC_VER) && !defined(__INTEL_COMPILER)
-  #pragma GCC diagnostic pop
+#    pragma GCC diagnostic pop
 #endif
diff --git a/tests/test_pickling.cpp b/tests/test_pickling.cpp
index b77636dd1a..2d27ac27b7 100644
--- a/tests/test_pickling.cpp
+++ b/tests/test_pickling.cpp
@@ -20,11 +20,11 @@
 namespace exercise_trampoline {
 
 struct SimpleBase {
-    int num               = 0;
+    int num = 0;
     virtual ~SimpleBase() = default;
 
     // For compatibility with old clang versions:
-    SimpleBase()                   = default;
+    SimpleBase() = default;
     SimpleBase(const SimpleBase &) = default;
 };
 
@@ -48,7 +48,7 @@ void wrap(py::module m) {
                     throw std::runtime_error("Invalid state!");
                 auto cpp_state = std::unique_ptr<SimpleBase>(new SimpleBaseTrampoline);
                 cpp_state->num = t[0].cast<int>();
-                auto py_state  = t[1].cast<py::dict>();
+                auto py_state = t[1].cast<py::dict>();
                 return std::make_pair(std::move(cpp_state), py_state);
             }));
 
diff --git a/tests/test_pytypes.cpp b/tests/test_pytypes.cpp
index 85cb98fcbf..034e1416bd 100644
--- a/tests/test_pytypes.cpp
+++ b/tests/test_pytypes.cpp
@@ -7,22 +7,21 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include <utility>
-
 #include "pybind11_tests.h"
 
+#include <utility>
 
 TEST_SUBMODULE(pytypes, m) {
     // test_bool
-    m.def("get_bool", []{return py::bool_(false);});
+    m.def("get_bool", [] { return py::bool_(false); });
     // test_int
-    m.def("get_int", []{return py::int_(0);});
+    m.def("get_int", [] { return py::int_(0); });
     // test_iterator
-    m.def("get_iterator", []{return py::iterator();});
+    m.def("get_iterator", [] { return py::iterator(); });
     // test_iterable
-    m.def("get_iterable", []{return py::iterable();});
+    m.def("get_iterable", [] { return py::iterable(); });
     // test_float
-    m.def("get_float", []{return py::float_(0.0f);});
+    m.def("get_float", [] { return py::float_(0.0f); });
     // test_list
     m.def("list_no_args", []() { return py::list{}; });
     m.def("list_ssize_t", []() { return py::list{(py::ssize_t) 0}; });
@@ -44,7 +43,7 @@ TEST_SUBMODULE(pytypes, m) {
             py::print("list item {}: {}"_s.format(index++, item));
     });
     // test_none
-    m.def("get_none", []{return py::none();});
+    m.def("get_none", [] { return py::none(); });
     m.def("print_none", [](const py::none &none) { py::print("none: {}"_s.format(none)); });
 
     // test_set
@@ -64,14 +63,14 @@ TEST_SUBMODULE(pytypes, m) {
     m.def("set_contains", [](const py::set &set, const char *key) { return set.contains(key); });
 
     // test_dict
-    m.def("get_dict", []() { return py::dict("key"_a="value"); });
+    m.def("get_dict", []() { return py::dict("key"_a = "value"); });
     m.def("print_dict", [](const py::dict &dict) {
         for (auto item : dict)
             py::print("key: {}, value={}"_s.format(item.first, item.second));
     });
     m.def("dict_keyword_constructor", []() {
-        auto d1 = py::dict("x"_a=1, "y"_a=2);
-        auto d2 = py::dict("z"_a=3, **d1);
+        auto d1 = py::dict("x"_a = 1, "y"_a = 2);
+        auto d2 = py::dict("z"_a = 3, **d1);
         return d2;
     });
     m.def("dict_contains",
@@ -88,7 +87,8 @@ TEST_SUBMODULE(pytypes, m) {
 #if PY_VERSION_HEX >= 0x03030000
     // test_simple_namespace
     m.def("get_simple_namespace", []() {
-        auto ns = py::module_::import("types").attr("SimpleNamespace")("attr"_a=42, "x"_a="foo", "wrong"_a=1);
+        auto ns = py::module_::import("types").attr("SimpleNamespace")(
+            "attr"_a = 42, "x"_a = "foo", "wrong"_a = 1);
         py::delattr(ns, "wrong");
         py::setattr(ns, "right", py::int_(2));
         return ns;
@@ -100,16 +100,15 @@ TEST_SUBMODULE(pytypes, m) {
     m.def("str_from_char_size_t", []() { return py::str{"blue", (py::size_t) 4}; });
     m.def("str_from_string", []() { return py::str(std::string("baz")); });
     m.def("str_from_bytes", []() { return py::str(py::bytes("boo", 3)); });
-    m.def("str_from_object", [](const py::object& obj) { return py::str(obj); });
-    m.def("repr_from_object", [](const py::object& obj) { return py::repr(obj); });
+    m.def("str_from_object", [](const py::object &obj) { return py::str(obj); });
+    m.def("repr_from_object", [](const py::object &obj) { return py::repr(obj); });
     m.def("str_from_handle", [](py::handle h) { return py::str(h); });
-    m.def("str_from_string_from_str", [](const py::str& obj) {
-        return py::str(static_cast<std::string>(obj));
-    });
+    m.def("str_from_string_from_str",
+          [](const py::str &obj) { return py::str(static_cast<std::string>(obj)); });
 
     m.def("str_format", []() {
         auto s1 = "{} + {} = {}"_s.format(1, 2, 3);
-        auto s2 = "{a} + {b} = {c}"_s.format("a"_a=1, "b"_a=2, "c"_a=3);
+        auto s2 = "{a} + {b} = {c}"_s.format("a"_a = 1, "b"_a = 2, "c"_a = 3);
         return py::make_tuple(s1, s2);
     });
 
@@ -128,9 +127,7 @@ TEST_SUBMODULE(pytypes, m) {
     // test_capsule
     m.def("return_capsule_with_destructor", []() {
         py::print("creating capsule");
-        return py::capsule([]() {
-            py::print("destructing capsule");
-        });
+        return py::capsule([]() { py::print("destructing capsule"); });
     });
 
     m.def("return_capsule_with_destructor_2", []() {
@@ -143,25 +140,25 @@ TEST_SUBMODULE(pytypes, m) {
     m.def("return_capsule_with_name_and_destructor", []() {
         auto capsule = py::capsule((void *) 12345, "pointer type description", [](PyObject *ptr) {
             if (ptr) {
-                auto name = PyCapsule_GetName(ptr);
+                const auto *name = PyCapsule_GetName(ptr);
                 py::print("destructing capsule ({}, '{}')"_s.format(
-                    (size_t) PyCapsule_GetPointer(ptr, name), name
-                ));
+                    (size_t) PyCapsule_GetPointer(ptr, name), name));
             }
         });
 
         capsule.set_pointer((void *) 1234);
 
         // Using get_pointer<T>()
-        void* contents1 = static_cast<void*>(capsule);
-        void* contents2 = capsule.get_pointer();
-        void* contents3 = capsule.get_pointer<void>();
+        void *contents1 = static_cast<void *>(capsule);
+        void *contents2 = capsule.get_pointer();
+        void *contents3 = capsule.get_pointer<void>();
 
         auto result1 = reinterpret_cast<size_t>(contents1);
         auto result2 = reinterpret_cast<size_t>(contents2);
         auto result3 = reinterpret_cast<size_t>(contents3);
 
-        py::print("created capsule ({}, '{}')"_s.format(result1 & result2 & result3, capsule.name()));
+        py::print(
+            "created capsule ({}, '{}')"_s.format(result1 & result2 & result3, capsule.name()));
         return capsule;
     });
 
@@ -241,51 +238,45 @@ TEST_SUBMODULE(pytypes, m) {
 
     // test_constructors
     m.def("default_constructors", []() {
-        return py::dict(
-            "bytes"_a=py::bytes(),
-            "bytearray"_a=py::bytearray(),
-            "str"_a=py::str(),
-            "bool"_a=py::bool_(),
-            "int"_a=py::int_(),
-            "float"_a=py::float_(),
-            "tuple"_a=py::tuple(),
-            "list"_a=py::list(),
-            "dict"_a=py::dict(),
-            "set"_a=py::set()
-        );
+        return py::dict("bytes"_a = py::bytes(),
+                        "bytearray"_a = py::bytearray(),
+                        "str"_a = py::str(),
+                        "bool"_a = py::bool_(),
+                        "int"_a = py::int_(),
+                        "float"_a = py::float_(),
+                        "tuple"_a = py::tuple(),
+                        "list"_a = py::list(),
+                        "dict"_a = py::dict(),
+                        "set"_a = py::set());
     });
 
     m.def("converting_constructors", [](const py::dict &d) {
-        return py::dict(
-            "bytes"_a=py::bytes(d["bytes"]),
-            "bytearray"_a=py::bytearray(d["bytearray"]),
-            "str"_a=py::str(d["str"]),
-            "bool"_a=py::bool_(d["bool"]),
-            "int"_a=py::int_(d["int"]),
-            "float"_a=py::float_(d["float"]),
-            "tuple"_a=py::tuple(d["tuple"]),
-            "list"_a=py::list(d["list"]),
-            "dict"_a=py::dict(d["dict"]),
-            "set"_a=py::set(d["set"]),
-            "memoryview"_a=py::memoryview(d["memoryview"])
-        );
+        return py::dict("bytes"_a = py::bytes(d["bytes"]),
+                        "bytearray"_a = py::bytearray(d["bytearray"]),
+                        "str"_a = py::str(d["str"]),
+                        "bool"_a = py::bool_(d["bool"]),
+                        "int"_a = py::int_(d["int"]),
+                        "float"_a = py::float_(d["float"]),
+                        "tuple"_a = py::tuple(d["tuple"]),
+                        "list"_a = py::list(d["list"]),
+                        "dict"_a = py::dict(d["dict"]),
+                        "set"_a = py::set(d["set"]),
+                        "memoryview"_a = py::memoryview(d["memoryview"]));
     });
 
     m.def("cast_functions", [](const py::dict &d) {
         // When converting between Python types, obj.cast<T>() should be the same as T(obj)
-        return py::dict(
-            "bytes"_a=d["bytes"].cast<py::bytes>(),
-            "bytearray"_a=d["bytearray"].cast<py::bytearray>(),
-            "str"_a=d["str"].cast<py::str>(),
-            "bool"_a=d["bool"].cast<py::bool_>(),
-            "int"_a=d["int"].cast<py::int_>(),
-            "float"_a=d["float"].cast<py::float_>(),
-            "tuple"_a=d["tuple"].cast<py::tuple>(),
-            "list"_a=d["list"].cast<py::list>(),
-            "dict"_a=d["dict"].cast<py::dict>(),
-            "set"_a=d["set"].cast<py::set>(),
-            "memoryview"_a=d["memoryview"].cast<py::memoryview>()
-        );
+        return py::dict("bytes"_a = d["bytes"].cast<py::bytes>(),
+                        "bytearray"_a = d["bytearray"].cast<py::bytearray>(),
+                        "str"_a = d["str"].cast<py::str>(),
+                        "bool"_a = d["bool"].cast<py::bool_>(),
+                        "int"_a = d["int"].cast<py::int_>(),
+                        "float"_a = d["float"].cast<py::float_>(),
+                        "tuple"_a = d["tuple"].cast<py::tuple>(),
+                        "list"_a = d["list"].cast<py::list>(),
+                        "dict"_a = d["dict"].cast<py::dict>(),
+                        "set"_a = d["set"].cast<py::set>(),
+                        "memoryview"_a = d["memoryview"].cast<py::memoryview>());
     });
 
     m.def("convert_to_pybind11_str", [](const py::object &o) { return py::str(o); });
@@ -338,10 +329,7 @@ TEST_SUBMODULE(pytypes, m) {
         l.append(py::cast(12));
         l.append(py::int_(15));
 
-        return py::dict(
-            "d"_a=d,
-            "l"_a=l
-        );
+        return py::dict("d"_a = d, "l"_a = l);
     });
 
     // test_print
@@ -349,16 +337,17 @@ TEST_SUBMODULE(pytypes, m) {
         py::print("Hello, World!");
         py::print(1, 2.0, "three", true, std::string("-- multiple args"));
         auto args = py::make_tuple("and", "a", "custom", "separator");
-        py::print("*args", *args, "sep"_a="-");
-        py::print("no new line here", "end"_a=" -- ");
+        py::print("*args", *args, "sep"_a = "-");
+        py::print("no new line here", "end"_a = " -- ");
         py::print("next print");
 
         auto py_stderr = py::module_::import("sys").attr("stderr");
-        py::print("this goes to stderr", "file"_a=py_stderr);
+        py::print("this goes to stderr", "file"_a = py_stderr);
 
-        py::print("flush", "flush"_a=true);
+        py::print("flush", "flush"_a = true);
 
-        py::print("{a} + {b} = {c}"_s.format("a"_a="py::print", "b"_a="str.format", "c"_a="this"));
+        py::print(
+            "{a} + {b} = {c}"_s.format("a"_a = "py::print", "b"_a = "str.format", "c"_a = "this"));
     });
 
     m.def("print_failure", []() { py::print(42, UnregisteredType()); });
@@ -403,41 +392,37 @@ TEST_SUBMODULE(pytypes, m) {
           [](const py::buffer &b) { return py::memoryview(b.request()); });
 
     m.def("test_memoryview_from_buffer", [](bool is_unsigned) {
-        static const int16_t si16[] = { 3, 1, 4, 1, 5 };
-        static const uint16_t ui16[] = { 2, 7, 1, 8 };
+        static const int16_t si16[] = {3, 1, 4, 1, 5};
+        static const uint16_t ui16[] = {2, 7, 1, 8};
         if (is_unsigned)
-            return py::memoryview::from_buffer(
-                ui16, { 4 }, { sizeof(uint16_t) });
+            return py::memoryview::from_buffer(ui16, {4}, {sizeof(uint16_t)});
         return py::memoryview::from_buffer(si16, {5}, {sizeof(int16_t)});
     });
 
     m.def("test_memoryview_from_buffer_nativeformat", []() {
-        static const char* format = "@i";
-        static const int32_t arr[] = { 4, 7, 5 };
-        return py::memoryview::from_buffer(
-            arr, sizeof(int32_t), format, { 3 }, { sizeof(int32_t) });
+        static const char *format = "@i";
+        static const int32_t arr[] = {4, 7, 5};
+        return py::memoryview::from_buffer(arr, sizeof(int32_t), format, {3}, {sizeof(int32_t)});
     });
 
     m.def("test_memoryview_from_buffer_empty_shape", []() {
-        static const char* buf = "";
-        return py::memoryview::from_buffer(buf, 1, "B", { }, { });
+        static const char *buf = "";
+        return py::memoryview::from_buffer(buf, 1, "B", {}, {});
     });
 
     m.def("test_memoryview_from_buffer_invalid_strides", []() {
-        static const char* buf = "\x02\x03\x04";
-        return py::memoryview::from_buffer(buf, 1, "B", { 3 }, { });
+        static const char *buf = "\x02\x03\x04";
+        return py::memoryview::from_buffer(buf, 1, "B", {3}, {});
     });
 
     m.def("test_memoryview_from_buffer_nullptr", []() {
-        return py::memoryview::from_buffer(
-            static_cast<void*>(nullptr), 1, "B", { }, { });
+        return py::memoryview::from_buffer(static_cast<void *>(nullptr), 1, "B", {}, {});
     });
 
 #if PY_MAJOR_VERSION >= 3
     m.def("test_memoryview_from_memory", []() {
-        const char* buf = "\xff\xe1\xab\x37";
-        return py::memoryview::from_memory(
-            buf, static_cast<py::ssize_t>(strlen(buf)));
+        const char *buf = "\xff\xe1\xab\x37";
+        return py::memoryview::from_memory(buf, static_cast<py::ssize_t>(strlen(buf)));
     });
 #endif
 
@@ -458,8 +443,7 @@ TEST_SUBMODULE(pytypes, m) {
     m.def("pass_to_std_string", [](const std::string &s) { return s.size(); });
 
     // test_weakref
-    m.def("weakref_from_handle",
-          [](py::handle h) { return py::weakref(h); });
+    m.def("weakref_from_handle", [](py::handle h) { return py::weakref(h); });
     m.def("weakref_from_handle_and_function",
           [](py::handle h, py::function f) { return py::weakref(h, std::move(f)); });
     m.def("weakref_from_object", [](const py::object &o) { return py::weakref(o); });
diff --git a/tests/test_sequences_and_iterators.cpp b/tests/test_sequences_and_iterators.cpp
index a378128ae2..76bdac9d8e 100644
--- a/tests/test_sequences_and_iterators.cpp
+++ b/tests/test_sequences_and_iterators.cpp
@@ -8,44 +8,52 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
-#include "constructor_stats.h"
 #include <pybind11/operators.h>
 #include <pybind11/stl.h>
 
+#include "constructor_stats.h"
+#include "pybind11_tests.h"
+
 #include <algorithm>
 #include <utility>
 #include <vector>
 
 #ifdef PYBIND11_HAS_OPTIONAL
-#include <optional>
-#endif  // PYBIND11_HAS_OPTIONAL
-
+#    include <optional>
+#endif // PYBIND11_HAS_OPTIONAL
 
-template<typename T>
+template <typename T>
 class NonZeroIterator {
-    const T* ptr_;
+    const T *ptr_;
+
 public:
     explicit NonZeroIterator(const T *ptr) : ptr_(ptr) {}
-    const T& operator*() const { return *ptr_; }
-    NonZeroIterator& operator++() { ++ptr_; return *this; }
+    const T &operator*() const { return *ptr_; }
+    NonZeroIterator &operator++() {
+        ++ptr_;
+        return *this;
+    }
 };
 
 class NonZeroSentinel {};
 
-template<typename A, typename B>
-bool operator==(const NonZeroIterator<std::pair<A, B>>& it, const NonZeroSentinel&) {
+template <typename A, typename B>
+bool operator==(const NonZeroIterator<std::pair<A, B>> &it, const NonZeroSentinel &) {
     return !(*it).first || !(*it).second;
 }
 
 /* Iterator where dereferencing returns prvalues instead of references. */
-template<typename T>
+template <typename T>
 class NonRefIterator {
-    const T* ptr_;
+    const T *ptr_;
+
 public:
     explicit NonRefIterator(const T *ptr) : ptr_(ptr) {}
     T operator*() const { return T(*ptr_); }
-    NonRefIterator& operator++() { ++ptr_; return *this; }
+    NonRefIterator &operator++() {
+        ++ptr_;
+        return *this;
+    }
     bool operator==(const NonRefIterator &other) const { return ptr_ == other.ptr_; }
 };
 
@@ -54,17 +62,18 @@ class NonCopyableInt {
     explicit NonCopyableInt(int value) : value_(value) {}
     NonCopyableInt(const NonCopyableInt &) = delete;
     NonCopyableInt(NonCopyableInt &&other) noexcept : value_(other.value_) {
-        other.value_ = -1;  // detect when an unwanted move occurs
+        other.value_ = -1; // detect when an unwanted move occurs
     }
     NonCopyableInt &operator=(const NonCopyableInt &) = delete;
     NonCopyableInt &operator=(NonCopyableInt &&other) noexcept {
         value_ = other.value_;
-        other.value_ = -1;  // detect when an unwanted move occurs
+        other.value_ = -1; // detect when an unwanted move occurs
         return *this;
     }
     int get() const { return value_; }
     void set(int value) { value_ = value; }
     ~NonCopyableInt() = default;
+
 private:
     int value_;
 };
@@ -80,7 +89,9 @@ py::list test_random_access_iterator(PythonType x) {
     auto checks = py::list();
     auto assert_equal = [&checks](py::handle a, py::handle b) {
         auto result = PyObject_RichCompareBool(a.ptr(), b.ptr(), Py_EQ);
-        if (result == -1) { throw py::error_already_set(); }
+        if (result == -1) {
+            throw py::error_already_set();
+        }
         checks.append(result != 0);
     };
 
@@ -115,7 +126,7 @@ py::list test_random_access_iterator(PythonType x) {
 
 TEST_SUBMODULE(sequences_and_iterators, m) {
     // test_sliceable
-    class Sliceable{
+    class Sliceable {
     public:
         explicit Sliceable(int n) : size(n) {}
         int start, stop, step;
@@ -128,18 +139,20 @@ TEST_SUBMODULE(sequences_and_iterators, m) {
             if (!slice.compute(s.size, &start, &stop, &step, &slicelength))
                 throw py::error_already_set();
             int istart = static_cast<int>(start);
-            int istop  = static_cast<int>(stop);
-            int istep  = static_cast<int>(step);
+            int istop = static_cast<int>(stop);
+            int istep = static_cast<int>(step);
             return std::make_tuple(istart, istop, istep);
         });
 
     m.def("make_forward_slice_size_t", []() { return py::slice(0, -1, 1); });
-    m.def("make_reversed_slice_object", []() { return py::slice(py::none(), py::none(), py::int_(-1)); });
+    m.def("make_reversed_slice_object",
+          []() { return py::slice(py::none(), py::none(), py::int_(-1)); });
 #ifdef PYBIND11_HAS_OPTIONAL
     m.attr("has_optional") = true;
-    m.def("make_reversed_slice_size_t_optional_verbose", []() { return py::slice(std::nullopt, std::nullopt, -1); });
-    // Warning: The following spelling may still compile if optional<> is not present and give wrong answers.
-    // Please use with caution.
+    m.def("make_reversed_slice_size_t_optional_verbose",
+          []() { return py::slice(std::nullopt, std::nullopt, -1); });
+    // Warning: The following spelling may still compile if optional<> is not present and give
+    // wrong answers. Please use with caution.
     m.def("make_reversed_slice_size_t_optional", []() { return py::slice({}, {}, -1); });
 #else
     m.attr("has_optional") = false;
@@ -156,12 +169,12 @@ TEST_SUBMODULE(sequences_and_iterators, m) {
         explicit Sequence(const std::vector<float> &value) : m_size(value.size()) {
             print_created(this, "of size", m_size, "from std::vector");
             m_data = new float[m_size];
-            memcpy(m_data, &value[0], sizeof(float) * m_size);
+            memcpy(m_data, value.data(), sizeof(float) * m_size);
         }
         Sequence(const Sequence &s) : m_size(s.m_size) {
             print_copy_created(this);
             m_data = new float[m_size];
-            memcpy(m_data, s.m_data, sizeof(float)*m_size);
+            memcpy(m_data, s.m_data, sizeof(float) * m_size);
         }
         Sequence(Sequence &&s) noexcept : m_size(s.m_size), m_data(s.m_data) {
             print_move_created(this);
@@ -169,14 +182,17 @@ TEST_SUBMODULE(sequences_and_iterators, m) {
             s.m_data = nullptr;
         }
 
-        ~Sequence() { print_destroyed(this); delete[] m_data; }
+        ~Sequence() {
+            print_destroyed(this);
+            delete[] m_data;
+        }
 
         Sequence &operator=(const Sequence &s) {
             if (&s != this) {
                 delete[] m_data;
                 m_size = s.m_size;
                 m_data = new float[m_size];
-                memcpy(m_data, s.m_data, sizeof(float)*m_size);
+                memcpy(m_data, s.m_data, sizeof(float) * m_size);
             }
             print_copy_assigned(this);
             return *this;
@@ -195,7 +211,8 @@ TEST_SUBMODULE(sequences_and_iterators, m) {
         }
 
         bool operator==(const Sequence &s) const {
-            if (m_size != s.size()) return false;
+            if (m_size != s.size())
+                return false;
             for (size_t i = 0; i < m_size; ++i)
                 if (m_data[i] != s[i])
                     return false;
@@ -223,7 +240,7 @@ TEST_SUBMODULE(sequences_and_iterators, m) {
         size_t size() const { return m_size; }
 
         const float *begin() const { return m_data; }
-        const float *end() const { return m_data+m_size; }
+        const float *end() const { return m_data + m_size; }
 
     private:
         size_t m_size;
@@ -286,8 +303,8 @@ TEST_SUBMODULE(sequences_and_iterators, m) {
         ;
 
     // test_map_iterator
-    // Interface of a map-like object that isn't (directly) an unordered_map, but provides some basic
-    // map-like functionality.
+    // Interface of a map-like object that isn't (directly) an unordered_map, but provides some
+    // basic map-like functionality.
     class StringMap {
     public:
         StringMap() = default;
@@ -297,8 +314,10 @@ TEST_SUBMODULE(sequences_and_iterators, m) {
         void set(const std::string &key, std::string val) { map[key] = std::move(val); }
         std::string get(const std::string &key) const { return map.at(key); }
         size_t size() const { return map.size(); }
+
     private:
         std::unordered_map<std::string, std::string> map;
+
     public:
         decltype(map.cbegin()) begin() const { return map.cbegin(); }
         decltype(map.cend()) end() const { return map.cend(); }
@@ -333,90 +352,115 @@ TEST_SUBMODULE(sequences_and_iterators, m) {
     class IntPairs {
     public:
         explicit IntPairs(std::vector<std::pair<int, int>> data) : data_(std::move(data)) {}
-        const std::pair<int, int>* begin() const { return data_.data(); }
+        const std::pair<int, int> *begin() const { return data_.data(); }
         // .end() only required for py::make_iterator(self) overload
-        const std::pair<int, int>* end() const { return data_.data() + data_.size(); }
+        const std::pair<int, int> *end() const { return data_.data() + data_.size(); }
+
     private:
         std::vector<std::pair<int, int>> data_;
     };
     py::class_<IntPairs>(m, "IntPairs")
         .def(py::init<std::vector<std::pair<int, int>>>())
-        .def("nonzero", [](const IntPairs& s) {
-            return py::make_iterator(NonZeroIterator<std::pair<int, int>>(s.begin()), NonZeroSentinel());
-        }, py::keep_alive<0, 1>())
-        .def("nonzero_keys", [](const IntPairs& s) {
-            return py::make_key_iterator(NonZeroIterator<std::pair<int, int>>(s.begin()), NonZeroSentinel());
-        }, py::keep_alive<0, 1>())
-        .def("nonzero_values", [](const IntPairs& s) {
-            return py::make_value_iterator(NonZeroIterator<std::pair<int, int>>(s.begin()), NonZeroSentinel());
-        }, py::keep_alive<0, 1>())
+        .def(
+            "nonzero",
+            [](const IntPairs &s) {
+                return py::make_iterator(NonZeroIterator<std::pair<int, int>>(s.begin()),
+                                         NonZeroSentinel());
+            },
+            py::keep_alive<0, 1>())
+        .def(
+            "nonzero_keys",
+            [](const IntPairs &s) {
+                return py::make_key_iterator(NonZeroIterator<std::pair<int, int>>(s.begin()),
+                                             NonZeroSentinel());
+            },
+            py::keep_alive<0, 1>())
+        .def(
+            "nonzero_values",
+            [](const IntPairs &s) {
+                return py::make_value_iterator(NonZeroIterator<std::pair<int, int>>(s.begin()),
+                                               NonZeroSentinel());
+            },
+            py::keep_alive<0, 1>())
 
         // test iterator that returns values instead of references
-        .def("nonref", [](const IntPairs& s) {
-             return py::make_iterator(NonRefIterator<std::pair<int, int>>(s.begin()),
-                                      NonRefIterator<std::pair<int, int>>(s.end()));
-        }, py::keep_alive<0, 1>())
-        .def("nonref_keys", [](const IntPairs& s) {
-             return py::make_key_iterator(NonRefIterator<std::pair<int, int>>(s.begin()),
-                                          NonRefIterator<std::pair<int, int>>(s.end()));
-        }, py::keep_alive<0, 1>())
-        .def("nonref_values", [](const IntPairs& s) {
-             return py::make_value_iterator(NonRefIterator<std::pair<int, int>>(s.begin()),
-                                            NonRefIterator<std::pair<int, int>>(s.end()));
-        }, py::keep_alive<0, 1>())
+        .def(
+            "nonref",
+            [](const IntPairs &s) {
+                return py::make_iterator(NonRefIterator<std::pair<int, int>>(s.begin()),
+                                         NonRefIterator<std::pair<int, int>>(s.end()));
+            },
+            py::keep_alive<0, 1>())
+        .def(
+            "nonref_keys",
+            [](const IntPairs &s) {
+                return py::make_key_iterator(NonRefIterator<std::pair<int, int>>(s.begin()),
+                                             NonRefIterator<std::pair<int, int>>(s.end()));
+            },
+            py::keep_alive<0, 1>())
+        .def(
+            "nonref_values",
+            [](const IntPairs &s) {
+                return py::make_value_iterator(NonRefIterator<std::pair<int, int>>(s.begin()),
+                                               NonRefIterator<std::pair<int, int>>(s.end()));
+            },
+            py::keep_alive<0, 1>())
 
         // test single-argument make_iterator
-        .def("simple_iterator", [](IntPairs& self) {
-            return py::make_iterator(self);
-        }, py::keep_alive<0, 1>())
-        .def("simple_keys", [](IntPairs& self) {
-            return py::make_key_iterator(self);
-        }, py::keep_alive<0, 1>())
-        .def("simple_values", [](IntPairs& self) {
-            return py::make_value_iterator(self);
-        }, py::keep_alive<0, 1>())
+        .def(
+            "simple_iterator",
+            [](IntPairs &self) { return py::make_iterator(self); },
+            py::keep_alive<0, 1>())
+        .def(
+            "simple_keys",
+            [](IntPairs &self) { return py::make_key_iterator(self); },
+            py::keep_alive<0, 1>())
+        .def(
+            "simple_values",
+            [](IntPairs &self) { return py::make_value_iterator(self); },
+            py::keep_alive<0, 1>())
 
         // Test iterator with an Extra (doesn't do anything useful, so not used
         // at runtime, but tests need to be able to compile with the correct
         // overload. See PR #3293.
-        .def("_make_iterator_extras", [](IntPairs& self) {
-            return py::make_iterator(self, py::call_guard<int>());
-        }, py::keep_alive<0, 1>())
-        .def("_make_key_extras", [](IntPairs& self) {
-            return py::make_key_iterator(self, py::call_guard<int>());
-        }, py::keep_alive<0, 1>())
-        .def("_make_value_extras", [](IntPairs& self) {
-            return py::make_value_iterator(self, py::call_guard<int>());
-        }, py::keep_alive<0, 1>())
-        ;
+        .def(
+            "_make_iterator_extras",
+            [](IntPairs &self) { return py::make_iterator(self, py::call_guard<int>()); },
+            py::keep_alive<0, 1>())
+        .def(
+            "_make_key_extras",
+            [](IntPairs &self) { return py::make_key_iterator(self, py::call_guard<int>()); },
+            py::keep_alive<0, 1>())
+        .def(
+            "_make_value_extras",
+            [](IntPairs &self) { return py::make_value_iterator(self, py::call_guard<int>()); },
+            py::keep_alive<0, 1>());
 
     // test_iterater_referencing
     py::class_<NonCopyableInt>(m, "NonCopyableInt")
         .def(py::init<int>())
         .def("set", &NonCopyableInt::set)
-        .def("__int__", &NonCopyableInt::get)
-        ;
+        .def("__int__", &NonCopyableInt::get);
     py::class_<std::vector<NonCopyableInt>>(m, "VectorNonCopyableInt")
         .def(py::init<>())
-        .def("append", [](std::vector<NonCopyableInt> &vec, int value) {
-            vec.emplace_back(value);
-        })
+        .def("append",
+             [](std::vector<NonCopyableInt> &vec, int value) { vec.emplace_back(value); })
         .def("__iter__", [](std::vector<NonCopyableInt> &vec) {
             return py::make_iterator(vec.begin(), vec.end());
-        })
-        ;
+        });
     py::class_<std::vector<NonCopyableIntPair>>(m, "VectorNonCopyableIntPair")
         .def(py::init<>())
-        .def("append", [](std::vector<NonCopyableIntPair> &vec, const std::pair<int, int> &value) {
-            vec.emplace_back(NonCopyableInt(value.first), NonCopyableInt(value.second));
-        })
-        .def("keys", [](std::vector<NonCopyableIntPair> &vec) {
-            return py::make_key_iterator(vec.begin(), vec.end());
-        })
+        .def("append",
+             [](std::vector<NonCopyableIntPair> &vec, const std::pair<int, int> &value) {
+                 vec.emplace_back(NonCopyableInt(value.first), NonCopyableInt(value.second));
+             })
+        .def("keys",
+             [](std::vector<NonCopyableIntPair> &vec) {
+                 return py::make_key_iterator(vec.begin(), vec.end());
+             })
         .def("values", [](std::vector<NonCopyableIntPair> &vec) {
             return py::make_value_iterator(vec.begin(), vec.end());
-        })
-        ;
+        });
 
 #if 0
     // Obsolete: special data structure for exposing custom iterator types to python
@@ -494,7 +538,9 @@ TEST_SUBMODULE(sequences_and_iterators, m) {
 
     // test_iterator_rvp
     // #388: Can't make iterators via make_iterator() with different r/v policies
-    static std::vector<int> list = { 1, 2, 3 };
-    m.def("make_iterator_1", []() { return py::make_iterator<py::return_value_policy::copy>(list); });
-    m.def("make_iterator_2", []() { return py::make_iterator<py::return_value_policy::automatic>(list); });
+    static std::vector<int> list = {1, 2, 3};
+    m.def("make_iterator_1",
+          []() { return py::make_iterator<py::return_value_policy::copy>(list); });
+    m.def("make_iterator_2",
+          []() { return py::make_iterator<py::return_value_policy::automatic>(list); });
 }
diff --git a/tests/test_smart_ptr.cpp b/tests/test_smart_ptr.cpp
index 94f04330a2..25a06aae35 100644
--- a/tests/test_smart_ptr.cpp
+++ b/tests/test_smart_ptr.cpp
@@ -8,21 +8,23 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#if defined(_MSC_VER) && _MSC_VER < 1910  // VS 2015's MSVC
-#  pragma warning(disable: 4702) // unreachable code in system header (xatomic.h(382))
+#if defined(_MSC_VER) && _MSC_VER < 1910 // VS 2015's MSVC
+#    pragma warning(disable : 4702)      // unreachable code in system header (xatomic.h(382))
 #endif
 
-#include "pybind11_tests.h"
 #include "object.h"
+#include "pybind11_tests.h"
 
 namespace {
 
 // This is just a wrapper around unique_ptr, but with extra fields to deliberately bloat up the
-// holder size to trigger the non-simple-layout internal instance layout for single inheritance with
-// large holder type:
-template <typename T> class huge_unique_ptr {
+// holder size to trigger the non-simple-layout internal instance layout for single inheritance
+// with large holder type:
+template <typename T>
+class huge_unique_ptr {
     std::unique_ptr<T> ptr;
     uint64_t padding[10];
+
 public:
     explicit huge_unique_ptr(T *p) : ptr(p) {}
     T *get() { return ptr.get(); }
@@ -32,10 +34,11 @@ template <typename T> class huge_unique_ptr {
 template <typename T>
 class custom_unique_ptr {
     std::unique_ptr<T> impl;
+
 public:
     explicit custom_unique_ptr(T *p) : impl(p) {}
-    T* get() const { return impl.get(); }
-    T* release_ptr() { return impl.release(); }
+    T *get() const { return impl.get(); }
+    T *release_ptr() { return impl.release(); }
 };
 
 // Simple custom holder that works like shared_ptr and has operator& overload
@@ -44,11 +47,12 @@ class custom_unique_ptr {
 template <typename T>
 class shared_ptr_with_addressof_operator {
     std::shared_ptr<T> impl;
+
 public:
-    shared_ptr_with_addressof_operator( ) = default;
+    shared_ptr_with_addressof_operator() = default;
     explicit shared_ptr_with_addressof_operator(T *p) : impl(p) {}
-    T* get() const { return impl.get(); }
-    T** operator&() { throw std::logic_error("Call of overloaded operator& is not expected"); }
+    T *get() const { return impl.get(); }
+    T **operator&() { throw std::logic_error("Call of overloaded operator& is not expected"); }
 };
 
 // Simple custom holder that works like unique_ptr and has operator& overload
@@ -57,12 +61,13 @@ class shared_ptr_with_addressof_operator {
 template <typename T>
 class unique_ptr_with_addressof_operator {
     std::unique_ptr<T> impl;
+
 public:
     unique_ptr_with_addressof_operator() = default;
     explicit unique_ptr_with_addressof_operator(T *p) : impl(p) {}
-    T* get() const { return impl.get(); }
-    T* release_ptr() { return impl.release(); }
-    T** operator&() { throw std::logic_error("Call of overloaded operator& is not expected"); }
+    T *get() const { return impl.get(); }
+    T *release_ptr() { return impl.release(); }
+    T **operator&() { throw std::logic_error("Call of overloaded operator& is not expected"); }
 };
 
 // Custom object with builtin reference counting (see 'object.h' for the implementation)
@@ -70,8 +75,10 @@ class MyObject1 : public Object {
 public:
     explicit MyObject1(int value) : value(value) { print_created(this, toString()); }
     std::string toString() const override { return "MyObject1[" + std::to_string(value) + "]"; }
+
 protected:
     ~MyObject1() override { print_destroyed(this); }
+
 private:
     int value;
 };
@@ -83,6 +90,7 @@ class MyObject2 {
     explicit MyObject2(int value) : value(value) { print_created(this, toString()); }
     std::string toString() const { return "MyObject2[" + std::to_string(value) + "]"; }
     virtual ~MyObject2() { print_destroyed(this); }
+
 private:
     int value;
 };
@@ -94,6 +102,7 @@ class MyObject3 : public std::enable_shared_from_this<MyObject3> {
     explicit MyObject3(int value) : value(value) { print_created(this, toString()); }
     std::string toString() const { return "MyObject3[" + std::to_string(value) + "]"; }
     virtual ~MyObject3() { print_destroyed(this); }
+
 private:
     int value;
 };
@@ -113,9 +122,10 @@ class MyObject4 {
     static void cleanupAllInstances() {
         auto tmp = std::move(myobject4_instances);
         myobject4_instances.clear();
-        for (auto o : tmp)
+        for (auto *o : tmp)
             delete o;
     }
+
 private:
     ~MyObject4() {
         myobject4_instances.erase(this);
@@ -140,9 +150,10 @@ class MyObject4a {
     static void cleanupAllInstances() {
         auto tmp = std::move(myobject4a_instances);
         myobject4a_instances.clear();
-        for (auto o : tmp)
+        for (auto *o : tmp)
             delete o;
     }
+
 protected:
     virtual ~MyObject4a() {
         myobject4a_instances.erase(this);
@@ -231,14 +242,14 @@ struct TypeForMoveOnlyHolderWithAddressOf {
 };
 
 // test_smart_ptr_from_default
-struct HeldByDefaultHolder { };
+struct HeldByDefaultHolder {};
 
 // test_shared_ptr_gc
 // #187: issue involving std::shared_ptr<> return value policy & garbage collection
 struct ElementBase {
     virtual ~ElementBase() = default; /* Force creation of virtual table */
     ElementBase() = default;
-    ElementBase(const ElementBase&) = delete;
+    ElementBase(const ElementBase &) = delete;
 };
 
 struct ElementA : ElementBase {
@@ -258,11 +269,12 @@ struct ElementList {
 // It is always possible to construct a ref<T> from an Object* pointer without
 // possible inconsistencies, hence the 'true' argument at the end.
 // Make pybind11 aware of the non-standard getter member function
-namespace pybind11 { namespace detail {
-    template <typename T>
-    struct holder_helper<ref<T>> {
-        static const T *get(const ref<T> &p) { return p.get_ptr(); }
-    };
+namespace pybind11 {
+namespace detail {
+template <typename T>
+struct holder_helper<ref<T>> {
+    static const T *get(const ref<T> &p) { return p.get_ptr(); }
+};
 } // namespace detail
 } // namespace pybind11
 
@@ -286,8 +298,7 @@ TEST_SUBMODULE(smart_ptr, m) {
     py::class_<Object, ref<Object>> obj(m, "Object");
     obj.def("getRefCount", &Object::getRefCount);
 
-    py::class_<MyObject1, ref<MyObject1>>(m, "MyObject1", obj)
-        .def(py::init<int>());
+    py::class_<MyObject1, ref<MyObject1>>(m, "MyObject1", obj).def(py::init<int>());
     py::implicitly_convertible<py::int_, MyObject1>();
 
     m.def("make_object_1", []() -> Object * { return new MyObject1(1); });
@@ -306,25 +317,27 @@ TEST_SUBMODULE(smart_ptr, m) {
     // Expose constructor stats for the ref type
     m.def("cstats_ref", &ConstructorStats::get<ref_tag>);
 
-    py::class_<MyObject2, std::shared_ptr<MyObject2>>(m, "MyObject2")
-        .def(py::init<int>());
+    py::class_<MyObject2, std::shared_ptr<MyObject2>>(m, "MyObject2").def(py::init<int>());
     m.def("make_myobject2_1", []() { return new MyObject2(6); });
     m.def("make_myobject2_2", []() { return std::make_shared<MyObject2>(7); });
     m.def("print_myobject2_1", [](const MyObject2 *obj) { py::print(obj->toString()); });
     // NOLINTNEXTLINE(performance-unnecessary-value-param)
     m.def("print_myobject2_2", [](std::shared_ptr<MyObject2> obj) { py::print(obj->toString()); });
-    m.def("print_myobject2_3", [](const std::shared_ptr<MyObject2> &obj) { py::print(obj->toString()); });
-    m.def("print_myobject2_4", [](const std::shared_ptr<MyObject2> *obj) { py::print((*obj)->toString()); });
+    m.def("print_myobject2_3",
+          [](const std::shared_ptr<MyObject2> &obj) { py::print(obj->toString()); });
+    m.def("print_myobject2_4",
+          [](const std::shared_ptr<MyObject2> *obj) { py::print((*obj)->toString()); });
 
-    py::class_<MyObject3, std::shared_ptr<MyObject3>>(m, "MyObject3")
-        .def(py::init<int>());
+    py::class_<MyObject3, std::shared_ptr<MyObject3>>(m, "MyObject3").def(py::init<int>());
     m.def("make_myobject3_1", []() { return new MyObject3(8); });
     m.def("make_myobject3_2", []() { return std::make_shared<MyObject3>(9); });
     m.def("print_myobject3_1", [](const MyObject3 *obj) { py::print(obj->toString()); });
     // NOLINTNEXTLINE(performance-unnecessary-value-param)
     m.def("print_myobject3_2", [](std::shared_ptr<MyObject3> obj) { py::print(obj->toString()); });
-    m.def("print_myobject3_3", [](const std::shared_ptr<MyObject3> &obj) { py::print(obj->toString()); });
-    m.def("print_myobject3_4", [](const std::shared_ptr<MyObject3> *obj) { py::print((*obj)->toString()); });
+    m.def("print_myobject3_3",
+          [](const std::shared_ptr<MyObject3> &obj) { py::print(obj->toString()); });
+    m.def("print_myobject3_4",
+          [](const std::shared_ptr<MyObject3> *obj) { py::print((*obj)->toString()); });
 
     // test_smart_ptr_refcounting
     m.def("test_object1_refcounting", []() {
@@ -420,11 +433,18 @@ TEST_SUBMODULE(smart_ptr, m) {
              [](const HolderWithAddressOf *obj) { py::print((*obj).get()->toString()); });
 
     // test_move_only_holder_with_addressof_operator
-    using MoveOnlyHolderWithAddressOf = unique_ptr_with_addressof_operator<TypeForMoveOnlyHolderWithAddressOf>;
-    py::class_<TypeForMoveOnlyHolderWithAddressOf, MoveOnlyHolderWithAddressOf>(m, "TypeForMoveOnlyHolderWithAddressOf")
-        .def_static("make", []() { return MoveOnlyHolderWithAddressOf(new TypeForMoveOnlyHolderWithAddressOf(0)); })
+    using MoveOnlyHolderWithAddressOf
+        = unique_ptr_with_addressof_operator<TypeForMoveOnlyHolderWithAddressOf>;
+    py::class_<TypeForMoveOnlyHolderWithAddressOf, MoveOnlyHolderWithAddressOf>(
+        m, "TypeForMoveOnlyHolderWithAddressOf")
+        .def_static("make",
+                    []() {
+                        return MoveOnlyHolderWithAddressOf(
+                            new TypeForMoveOnlyHolderWithAddressOf(0));
+                    })
         .def_readwrite("value", &TypeForMoveOnlyHolderWithAddressOf::value)
-        .def("print_object", [](const TypeForMoveOnlyHolderWithAddressOf *obj) { py::print(obj->toString()); });
+        .def("print_object",
+             [](const TypeForMoveOnlyHolderWithAddressOf *obj) { py::print(obj->toString()); });
 
     // test_smart_ptr_from_default
     py::class_<HeldByDefaultHolder, std::unique_ptr<HeldByDefaultHolder>>(m, "HeldByDefaultHolder")
diff --git a/tests/test_stl.cpp b/tests/test_stl.cpp
index bc5c6553a2..44a6eb2e3e 100644
--- a/tests/test_stl.cpp
+++ b/tests/test_stl.cpp
@@ -7,39 +7,43 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
-#include "constructor_stats.h"
 #include <pybind11/stl.h>
 
+#include "constructor_stats.h"
+#include "pybind11_tests.h"
+
 #ifndef PYBIND11_HAS_FILESYSTEM_IS_OPTIONAL
-#define PYBIND11_HAS_FILESYSTEM_IS_OPTIONAL
+#    define PYBIND11_HAS_FILESYSTEM_IS_OPTIONAL
 #endif
 #include <pybind11/stl/filesystem.h>
 
-#include <vector>
 #include <string>
+#include <vector>
 
 #if defined(PYBIND11_TEST_BOOST)
-#include <boost/optional.hpp>
+#    include <boost/optional.hpp>
 
-namespace pybind11 { namespace detail {
+namespace pybind11 {
+namespace detail {
 template <typename T>
 struct type_caster<boost::optional<T>> : optional_caster<boost::optional<T>> {};
 
 template <>
 struct type_caster<boost::none_t> : void_caster<boost::none_t> {};
-}} // namespace pybind11::detail
+} // namespace detail
+} // namespace pybind11
 #endif
 
 // Test with `std::variant` in C++17 mode, or with `boost::variant` in C++11/14
 #if defined(PYBIND11_HAS_VARIANT)
 using std::variant;
 #elif defined(PYBIND11_TEST_BOOST) && (!defined(_MSC_VER) || _MSC_VER >= 1910)
-#  include <boost/variant.hpp>
-#  define PYBIND11_HAS_VARIANT 1
+#    include <boost/variant.hpp>
+#    define PYBIND11_HAS_VARIANT 1
 using boost::variant;
 
-namespace pybind11 { namespace detail {
+namespace pybind11 {
+namespace detail {
 template <typename... Ts>
 struct type_caster<boost::variant<Ts...>> : variant_caster<boost::variant<Ts...>> {};
 
@@ -50,7 +54,8 @@ struct visit_helper<boost::variant> {
         return boost::apply_visitor(args...);
     }
 };
-}} // namespace pybind11::detail
+} // namespace detail
+} // namespace pybind11
 #endif
 
 PYBIND11_MAKE_OPAQUE(std::vector<std::string, std::allocator<std::string>>);
@@ -63,26 +68,23 @@ struct TplCtorClass {
 };
 
 namespace std {
-    template <>
-    struct hash<TplCtorClass> { size_t operator()(const TplCtorClass &) const { return 0; } };
+template <>
+struct hash<TplCtorClass> {
+    size_t operator()(const TplCtorClass &) const { return 0; }
+};
 } // namespace std
 
-
 template <template <typename> class OptionalImpl, typename T>
-struct OptionalHolder
-{
+struct OptionalHolder {
     // NOLINTNEXTLINE(modernize-use-equals-default): breaks GCC 4.8
-    OptionalHolder() {};
-    bool member_initialized() const {
-        return member && member->initialized;
-    }
+    OptionalHolder(){};
+    bool member_initialized() const { return member && member->initialized; }
     OptionalImpl<T> member = T{};
 };
 
-
 enum class EnumType {
-  kSet = 42,
-  kUnset = 85,
+    kSet = 42,
+    kUnset = 85,
 };
 
 // This is used to test that return-by-ref and return-by-copy policies are
@@ -102,7 +104,7 @@ class OptionalProperties {
         value = EnumType::kUnset;
     }
 
-    OptionalEnumValue& access_by_ref() { return value; }
+    OptionalEnumValue &access_by_ref() { return value; }
     OptionalEnumValue access_by_copy() { return value; }
 
 private:
@@ -122,62 +124,56 @@ class ReferenceSensitiveOptional {
 
     ReferenceSensitiveOptional() = default;
     // NOLINTNEXTLINE(google-explicit-constructor)
-    ReferenceSensitiveOptional(const T& value) : storage{value} {}
+    ReferenceSensitiveOptional(const T &value) : storage{value} {}
     // NOLINTNEXTLINE(google-explicit-constructor)
-    ReferenceSensitiveOptional(T&& value) : storage{std::move(value)} {}
-    ReferenceSensitiveOptional& operator=(const T& value) {
+    ReferenceSensitiveOptional(T &&value) : storage{std::move(value)} {}
+    ReferenceSensitiveOptional &operator=(const T &value) {
         storage = {value};
         return *this;
     }
-    ReferenceSensitiveOptional& operator=(T&& value) {
+    ReferenceSensitiveOptional &operator=(T &&value) {
         storage = {std::move(value)};
         return *this;
     }
 
     template <typename... Args>
-    T& emplace(Args&&... args) {
+    T &emplace(Args &&...args) {
         storage.clear();
         storage.emplace_back(std::forward<Args>(args)...);
         return storage.back();
     }
 
-    const T& value() const noexcept {
+    const T &value() const noexcept {
         assert(!storage.empty());
         return storage[0];
     }
 
-    const T& operator*() const noexcept {
-        return value();
-    }
+    const T &operator*() const noexcept { return value(); }
 
-    const T* operator->() const noexcept {
-        return &value();
-    }
+    const T *operator->() const noexcept { return &value(); }
 
-    explicit operator bool() const noexcept {
-        return !storage.empty();
-    }
+    explicit operator bool() const noexcept { return !storage.empty(); }
 
 private:
     std::vector<T> storage;
 };
 
-namespace pybind11 { namespace detail {
+namespace pybind11 {
+namespace detail {
 template <typename T>
-struct type_caster<ReferenceSensitiveOptional<T>> : optional_caster<ReferenceSensitiveOptional<T>> {};
+struct type_caster<ReferenceSensitiveOptional<T>>
+    : optional_caster<ReferenceSensitiveOptional<T>> {};
 } // namespace detail
 } // namespace pybind11
 
-
 TEST_SUBMODULE(stl, m) {
     // test_vector
     m.def("cast_vector", []() { return std::vector<int>{1}; });
     m.def("load_vector", [](const std::vector<int> &v) { return v.at(0) == 1 && v.at(1) == 2; });
     // `std::vector<bool>` is special because it returns proxy objects instead of references
     m.def("cast_bool_vector", []() { return std::vector<bool>{true, false}; });
-    m.def("load_bool_vector", [](const std::vector<bool> &v) {
-        return v.at(0) == true && v.at(1) == false;
-    });
+    m.def("load_bool_vector",
+          [](const std::vector<bool> &v) { return v.at(0) == true && v.at(1) == false; });
     // Unnumbered regression (caused by #936): pointers to stl containers aren't castable
     static std::vector<RValueCaster> lvv{2};
     m.def("cast_ptr_vector", []() { return &lvv; });
@@ -187,12 +183,12 @@ TEST_SUBMODULE(stl, m) {
     m.def("load_deque", [](const std::deque<int> &v) { return v.at(0) == 1 && v.at(1) == 2; });
 
     // test_array
-    m.def("cast_array", []() { return std::array<int, 2> {{1 , 2}}; });
+    m.def("cast_array", []() { return std::array<int, 2>{{1, 2}}; });
     m.def("load_array", [](const std::array<int, 2> &a) { return a[0] == 1 && a[1] == 2; });
 
     // test_valarray
     m.def("cast_valarray", []() { return std::valarray<int>{1, 4, 9}; });
-    m.def("load_valarray", [](const std::valarray<int>& v) {
+    m.def("load_valarray", [](const std::valarray<int> &v) {
         return v.size() == 3 && v[0] == 1 && v[1] == 4 && v[2] == 9;
     });
 
@@ -214,10 +210,12 @@ TEST_SUBMODULE(stl, m) {
     // NB: map and set keys are `const`, so while we technically do move them (as `const Type &&`),
     // casters don't typically do anything with that, which means they fall to the `const Type &`
     // caster.
-    m.def("cast_rv_map", []() { return std::unordered_map<std::string, RValueCaster>{{"a", RValueCaster{}}}; });
+    m.def("cast_rv_map", []() {
+        return std::unordered_map<std::string, RValueCaster>{{"a", RValueCaster{}}};
+    });
     m.def("cast_rv_nested", []() {
         std::vector<std::array<std::list<std::unordered_map<std::string, RValueCaster>>, 2>> v;
-        v.emplace_back(); // add an array
+        v.emplace_back();           // add an array
         v.back()[0].emplace_back(); // add a map to the array
         v.back()[0].back().emplace("b", RValueCaster{});
         v.back()[0].back().emplace("c", RValueCaster{});
@@ -226,13 +224,15 @@ TEST_SUBMODULE(stl, m) {
         return v;
     });
     static std::array<RValueCaster, 2> lva;
-    static std::unordered_map<std::string, RValueCaster> lvm{{"a", RValueCaster{}}, {"b", RValueCaster{}}};
-    static std::unordered_map<std::string, std::vector<std::list<std::array<RValueCaster, 2>>>> lvn;
-    lvn["a"].emplace_back(); // add a list
+    static std::unordered_map<std::string, RValueCaster> lvm{{"a", RValueCaster{}},
+                                                             {"b", RValueCaster{}}};
+    static std::unordered_map<std::string, std::vector<std::list<std::array<RValueCaster, 2>>>>
+        lvn;
+    lvn["a"].emplace_back();        // add a list
     lvn["a"].back().emplace_back(); // add an array
-    lvn["a"].emplace_back(); // another list
+    lvn["a"].emplace_back();        // another list
     lvn["a"].back().emplace_back(); // add an array
-    lvn["b"].emplace_back(); // add a list
+    lvn["b"].emplace_back();        // add a list
     lvn["b"].back().emplace_back(); // add an array
     lvn["b"].back().emplace_back(); // add another array
     m.def("cast_lv_vector", []() -> const decltype(lvv) & { return lvv; });
@@ -253,7 +253,9 @@ TEST_SUBMODULE(stl, m) {
 
     // test_move_out_container
     struct MoveOutContainer {
-        struct Value { int value; };
+        struct Value {
+            int value;
+        };
         std::list<Value> move_list() const { return {{0}, {1}, {2}}; }
     };
     py::class_<MoveOutContainer::Value>(m, "MoveOutContainerValue")
@@ -266,7 +268,7 @@ TEST_SUBMODULE(stl, m) {
     struct NoAssign {
         int value;
 
-        explicit NoAssign(int value = 0) : value(value) { }
+        explicit NoAssign(int value = 0) : value(value) {}
         NoAssign(const NoAssign &) = default;
         NoAssign(NoAssign &&) = default;
 
@@ -277,13 +279,10 @@ TEST_SUBMODULE(stl, m) {
         .def(py::init<>())
         .def(py::init<int>());
 
-
-    struct MoveOutDetector
-    {
+    struct MoveOutDetector {
         MoveOutDetector() = default;
-        MoveOutDetector(const MoveOutDetector&) = default;
-        MoveOutDetector(MoveOutDetector&& other) noexcept
-         : initialized(other.initialized) {
+        MoveOutDetector(const MoveOutDetector &) = default;
+        MoveOutDetector(MoveOutDetector &&other) noexcept : initialized(other.initialized) {
             // steal underlying resource
             other.initialized = false;
         }
@@ -293,23 +292,22 @@ TEST_SUBMODULE(stl, m) {
         .def(py::init<>())
         .def_readonly("initialized", &MoveOutDetector::initialized);
 
-
 #ifdef PYBIND11_HAS_OPTIONAL
     // test_optional
     m.attr("has_optional") = true;
 
     using opt_int = std::optional<int>;
     using opt_no_assign = std::optional<NoAssign>;
-    m.def("double_or_zero", [](const opt_int& x) -> int {
-        return x.value_or(0) * 2;
-    });
+    m.def("double_or_zero", [](const opt_int &x) -> int { return x.value_or(0) * 2; });
     m.def("half_or_none", [](int x) -> opt_int { return x != 0 ? opt_int(x / 2) : opt_int(); });
-    m.def("test_nullopt", [](opt_int x) {
-        return x.value_or(42);
-    }, py::arg_v("x", std::nullopt, "None"));
-    m.def("test_no_assign", [](const opt_no_assign &x) {
-        return x ? x->value : 42;
-    }, py::arg_v("x", std::nullopt, "None"));
+    m.def(
+        "test_nullopt",
+        [](opt_int x) { return x.value_or(42); },
+        py::arg_v("x", std::nullopt, "None"));
+    m.def(
+        "test_no_assign",
+        [](const opt_no_assign &x) { return x ? x->value : 42; },
+        py::arg_v("x", std::nullopt, "None"));
 
     m.def("nodefer_none_optional", [](std::optional<int>) { return true; });
     m.def("nodefer_none_optional", [](const py::none &) { return false; });
@@ -333,18 +331,17 @@ TEST_SUBMODULE(stl, m) {
 
     using exp_opt_int = std::experimental::optional<int>;
     using exp_opt_no_assign = std::experimental::optional<NoAssign>;
-    m.def("double_or_zero_exp", [](const exp_opt_int& x) -> int {
-        return x.value_or(0) * 2;
-    });
-    m.def("half_or_none_exp", [](int x) -> exp_opt_int {
-        return x ? exp_opt_int(x / 2) : exp_opt_int();
-    });
-    m.def("test_nullopt_exp", [](exp_opt_int x) {
-        return x.value_or(42);
-    }, py::arg_v("x", std::experimental::nullopt, "None"));
-    m.def("test_no_assign_exp", [](const exp_opt_no_assign &x) {
-        return x ? x->value : 42;
-    }, py::arg_v("x", std::experimental::nullopt, "None"));
+    m.def("double_or_zero_exp", [](const exp_opt_int &x) -> int { return x.value_or(0) * 2; });
+    m.def("half_or_none_exp",
+          [](int x) -> exp_opt_int { return x ? exp_opt_int(x / 2) : exp_opt_int(); });
+    m.def(
+        "test_nullopt_exp",
+        [](exp_opt_int x) { return x.value_or(42); },
+        py::arg_v("x", std::experimental::nullopt, "None"));
+    m.def(
+        "test_no_assign_exp",
+        [](const exp_opt_no_assign &x) { return x ? x->value : 42; },
+        py::arg_v("x", std::experimental::nullopt, "None"));
 
     using opt_exp_holder = OptionalHolder<std::experimental::optional, MoveOutDetector>;
     py::class_<opt_exp_holder>(m, "OptionalExpHolder", "Class with optional member")
@@ -365,18 +362,17 @@ TEST_SUBMODULE(stl, m) {
 
     using boost_opt_int = boost::optional<int>;
     using boost_opt_no_assign = boost::optional<NoAssign>;
-    m.def("double_or_zero_boost", [](const boost_opt_int& x) -> int {
-        return x.value_or(0) * 2;
-    });
-    m.def("half_or_none_boost", [](int x) -> boost_opt_int {
-        return x != 0 ? boost_opt_int(x / 2) : boost_opt_int();
-    });
-    m.def("test_nullopt_boost", [](boost_opt_int x) {
-        return x.value_or(42);
-    }, py::arg_v("x", boost::none, "None"));
-    m.def("test_no_assign_boost", [](const boost_opt_no_assign &x) {
-        return x ? x->value : 42;
-    }, py::arg_v("x", boost::none, "None"));
+    m.def("double_or_zero_boost", [](const boost_opt_int &x) -> int { return x.value_or(0) * 2; });
+    m.def("half_or_none_boost",
+          [](int x) -> boost_opt_int { return x != 0 ? boost_opt_int(x / 2) : boost_opt_int(); });
+    m.def(
+        "test_nullopt_boost",
+        [](boost_opt_int x) { return x.value_or(42); },
+        py::arg_v("x", boost::none, "None"));
+    m.def(
+        "test_no_assign_boost",
+        [](const boost_opt_no_assign &x) { return x ? x->value : 42; },
+        py::arg_v("x", boost::none, "None"));
 
     using opt_boost_holder = OptionalHolder<boost::optional, MoveOutDetector>;
     py::class_<opt_boost_holder>(m, "OptionalBoostHolder", "Class with optional member")
@@ -394,22 +390,24 @@ TEST_SUBMODULE(stl, m) {
     // test_refsensitive_optional
     using refsensitive_opt_int = ReferenceSensitiveOptional<int>;
     using refsensitive_opt_no_assign = ReferenceSensitiveOptional<NoAssign>;
-    m.def("double_or_zero_refsensitive", [](const refsensitive_opt_int& x) -> int {
-        return (x ? x.value() : 0) * 2;
-    });
+    m.def("double_or_zero_refsensitive",
+          [](const refsensitive_opt_int &x) -> int { return (x ? x.value() : 0) * 2; });
     m.def("half_or_none_refsensitive", [](int x) -> refsensitive_opt_int {
         return x != 0 ? refsensitive_opt_int(x / 2) : refsensitive_opt_int();
     });
-    // NOLINTNEXTLINE(performance-unnecessary-value-param)
-    m.def("test_nullopt_refsensitive", [](refsensitive_opt_int x) {
-        return x ? x.value() : 42;
-    }, py::arg_v("x", refsensitive_opt_int(), "None"));
-    m.def("test_no_assign_refsensitive", [](const refsensitive_opt_no_assign &x) {
-        return x ? x->value : 42;
-    }, py::arg_v("x", refsensitive_opt_no_assign(), "None"));
+    m.def(
+        "test_nullopt_refsensitive",
+        // NOLINTNEXTLINE(performance-unnecessary-value-param)
+        [](refsensitive_opt_int x) { return x ? x.value() : 42; },
+        py::arg_v("x", refsensitive_opt_int(), "None"));
+    m.def(
+        "test_no_assign_refsensitive",
+        [](const refsensitive_opt_no_assign &x) { return x ? x->value : 42; },
+        py::arg_v("x", refsensitive_opt_no_assign(), "None"));
 
     using opt_refsensitive_holder = OptionalHolder<ReferenceSensitiveOptional, MoveOutDetector>;
-    py::class_<opt_refsensitive_holder>(m, "OptionalRefSensitiveHolder", "Class with optional member")
+    py::class_<opt_refsensitive_holder>(
+        m, "OptionalRefSensitiveHolder", "Class with optional member")
         .def(py::init<>())
         .def_readonly("member", &opt_refsensitive_holder::member)
         .def("member_initialized", &opt_refsensitive_holder::member_initialized);
@@ -423,7 +421,7 @@ TEST_SUBMODULE(stl, m) {
 #ifdef PYBIND11_HAS_FILESYSTEM
     // test_fs_path
     m.attr("has_filesystem") = true;
-    m.def("parent_path", [](const std::filesystem::path& p) { return p.parent_path(); });
+    m.def("parent_path", [](const std::filesystem::path &p) { return p.parent_path(); });
 #endif
 
 #ifdef PYBIND11_HAS_VARIANT
@@ -471,13 +469,13 @@ TEST_SUBMODULE(stl, m) {
     // #171: Can't return STL structures containing reference wrapper
     m.def("return_vec_of_reference_wrapper", [](std::reference_wrapper<UserType> p4) {
         static UserType p1{1}, p2{2}, p3{3};
-        return std::vector<std::reference_wrapper<UserType>> {
-            std::ref(p1), std::ref(p2), std::ref(p3), p4
-        };
+        return std::vector<std::reference_wrapper<UserType>>{
+            std::ref(p1), std::ref(p2), std::ref(p3), p4};
     });
 
     // test_stl_pass_by_pointer
-    m.def("stl_pass_by_pointer", [](std::vector<int>* v) { return *v; }, "v"_a=nullptr);
+    m.def(
+        "stl_pass_by_pointer", [](std::vector<int> *v) { return *v; }, "v"_a = nullptr);
 
     // #1258: pybind11/stl.h converts string to vector<string>
     m.def("func_with_string_or_vector_string_arg_overload",
@@ -495,19 +493,24 @@ TEST_SUBMODULE(stl, m) {
     py::class_<Placeholder>(m, "Placeholder");
 
     /// test_stl_vector_ownership
-    m.def("test_stl_ownership",
-          []() {
-              std::vector<Placeholder *> result;
-              result.push_back(new Placeholder());
-              return result;
-          },
-          py::return_value_policy::take_ownership);
+    m.def(
+        "test_stl_ownership",
+        []() {
+            std::vector<Placeholder *> result;
+            result.push_back(new Placeholder());
+            return result;
+        },
+        py::return_value_policy::take_ownership);
 
     m.def("array_cast_sequence", [](std::array<int, 3> x) { return x; });
 
     /// test_issue_1561
-    struct Issue1561Inner { std::string data; };
-    struct Issue1561Outer { std::vector<Issue1561Inner> list; };
+    struct Issue1561Inner {
+        std::string data;
+    };
+    struct Issue1561Outer {
+        std::vector<Issue1561Inner> list;
+    };
 
     py::class_<Issue1561Inner>(m, "Issue1561Inner")
         .def(py::init<std::string>())
diff --git a/tests/test_stl_binders.cpp b/tests/test_stl_binders.cpp
index 6b23e3529f..18516f45e8 100644
--- a/tests/test_stl_binders.cpp
+++ b/tests/test_stl_binders.cpp
@@ -7,12 +7,13 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
+#include <pybind11/numpy.h>
+#include <pybind11/stl_bind.h>
+
 #include "pybind11_tests.h"
 
-#include <pybind11/stl_bind.h>
-#include <pybind11/numpy.h>
-#include <map>
 #include <deque>
+#include <map>
 #include <unordered_map>
 
 class El {
@@ -23,7 +24,7 @@ class El {
     int a;
 };
 
-std::ostream & operator<<(std::ostream &s, El const&v) {
+std::ostream &operator<<(std::ostream &s, El const &v) {
     s << "El{" << v.a << '}';
     return s;
 }
@@ -40,25 +41,28 @@ class E_nc {
     int value;
 };
 
-template <class Container> Container *one_to_n(int n) {
-    auto v = new Container();
+template <class Container>
+Container *one_to_n(int n) {
+    auto *v = new Container();
     for (int i = 1; i <= n; i++)
         v->emplace_back(i);
     return v;
 }
 
-template <class Map> Map *times_ten(int n) {
-    auto m = new Map();
+template <class Map>
+Map *times_ten(int n) {
+    auto *m = new Map();
     for (int i = 1; i <= n; i++)
-        m->emplace(int(i), E_nc(10*i));
+        m->emplace(int(i), E_nc(10 * i));
     return m;
 }
 
-template <class NestMap> NestMap *times_hundred(int n) {
-    auto m = new NestMap();
+template <class NestMap>
+NestMap *times_hundred(int n) {
+    auto *m = new NestMap();
     for (int i = 1; i <= n; i++)
         for (int j = 1; j <= n; j++)
-            (*m)[i].emplace(int(j*10), E_nc(100*j));
+            (*m)[i].emplace(int(j * 10), E_nc(100 * j));
     return m;
 }
 
@@ -67,8 +71,7 @@ TEST_SUBMODULE(stl_binders, m) {
     py::bind_vector<std::vector<unsigned int>>(m, "VectorInt", py::buffer_protocol());
 
     // test_vector_custom
-    py::class_<El>(m, "El")
-        .def(py::init<int>());
+    py::class_<El>(m, "El").def(py::init<int>());
     py::bind_vector<std::vector<El>>(m, "VectorEl");
     py::bind_vector<std::vector<std::vector<El>>>(m, "VectorVectorEl");
 
@@ -78,11 +81,10 @@ TEST_SUBMODULE(stl_binders, m) {
 
     // test_map_string_double_const
     py::bind_map<std::map<std::string, double const>>(m, "MapStringDoubleConst");
-    py::bind_map<std::unordered_map<std::string, double const>>(m, "UnorderedMapStringDoubleConst");
+    py::bind_map<std::unordered_map<std::string, double const>>(m,
+                                                                "UnorderedMapStringDoubleConst");
 
-    py::class_<E_nc>(m, "ENC")
-        .def(py::init<int>())
-        .def_readwrite("value", &E_nc::value);
+    py::class_<E_nc>(m, "ENC").def(py::init<int>()).def_readwrite("value", &E_nc::value);
 
     // test_noncopyable_containers
     py::bind_vector<std::vector<E_nc>>(m, "VectorENC");
@@ -95,14 +97,13 @@ TEST_SUBMODULE(stl_binders, m) {
     m.def("get_umnc", &times_ten<std::unordered_map<int, E_nc>>);
     // Issue #1885: binding nested std::map<X, Container<E>> with E non-copyable
     py::bind_map<std::map<int, std::vector<E_nc>>>(m, "MapVecENC");
-    m.def("get_nvnc", [](int n)
-        {
-            auto m = new std::map<int, std::vector<E_nc>>();
-            for (int i = 1; i <= n; i++)
-                for (int j = 1; j <= n; j++)
-                    (*m)[i].emplace_back(j);
-            return m;
-        });
+    m.def("get_nvnc", [](int n) {
+        auto *m = new std::map<int, std::vector<E_nc>>();
+        for (int i = 1; i <= n; i++)
+            for (int j = 1; j <= n; j++)
+                (*m)[i].emplace_back(j);
+        return m;
+    });
     py::bind_map<std::map<int, std::map<int, E_nc>>>(m, "MapMapENC");
     m.def("get_nmnc", &times_hundred<std::map<int, std::map<int, E_nc>>>);
     py::bind_map<std::unordered_map<int, std::unordered_map<int, E_nc>>>(m, "UmapUmapENC");
@@ -111,17 +112,31 @@ TEST_SUBMODULE(stl_binders, m) {
     // test_vector_buffer
     py::bind_vector<std::vector<unsigned char>>(m, "VectorUChar", py::buffer_protocol());
     // no dtype declared for this version:
-    struct VUndeclStruct { bool w; uint32_t x; double y; bool z; };
-    m.def("create_undeclstruct", [m] () mutable {
-        py::bind_vector<std::vector<VUndeclStruct>>(m, "VectorUndeclStruct", py::buffer_protocol());
+    struct VUndeclStruct {
+        bool w;
+        uint32_t x;
+        double y;
+        bool z;
+    };
+    m.def("create_undeclstruct", [m]() mutable {
+        py::bind_vector<std::vector<VUndeclStruct>>(
+            m, "VectorUndeclStruct", py::buffer_protocol());
     });
 
     // The rest depends on numpy:
-    try { py::module_::import("numpy"); }
-    catch (...) { return; }
+    try {
+        py::module_::import("numpy");
+    } catch (...) {
+        return;
+    }
 
     // test_vector_buffer_numpy
-    struct VStruct { bool w; uint32_t x; double y; bool z; };
+    struct VStruct {
+        bool w;
+        uint32_t x;
+        double y;
+        bool z;
+    };
     PYBIND11_NUMPY_DTYPE(VStruct, w, x, y, z);
     py::class_<VStruct>(m, "VStruct").def_readwrite("x", &VStruct::x);
     py::bind_vector<std::vector<VStruct>>(m, "VectorStruct", py::buffer_protocol());
diff --git a/tests/test_tagbased_polymorphic.cpp b/tests/test_tagbased_polymorphic.cpp
index 2c7bad8bbc..7653598e28 100644
--- a/tests/test_tagbased_polymorphic.cpp
+++ b/tests/test_tagbased_polymorphic.cpp
@@ -7,11 +7,11 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
 #include <pybind11/stl.h>
 
-struct Animal
-{
+#include "pybind11_tests.h"
+
+struct Animal {
     // Make this type also a "standard" polymorphic type, to confirm that
     // specializing polymorphic_type_hook using enable_if_t still works
     // (https://github.com/pybind/pybind11/pull/2016/).
@@ -20,57 +20,54 @@ struct Animal
     // Enum for tag-based polymorphism.
     enum class Kind {
         Unknown = 0,
-        Dog = 100, Labrador, Chihuahua, LastDog = 199,
-        Cat = 200, Panther, LastCat = 299
+        Dog = 100,
+        Labrador,
+        Chihuahua,
+        LastDog = 199,
+        Cat = 200,
+        Panther,
+        LastCat = 299
     };
-    static const std::type_info* type_of_kind(Kind kind);
+    static const std::type_info *type_of_kind(Kind kind);
     static std::string name_of_kind(Kind kind);
 
     const Kind kind;
     const std::string name;
 
-  protected:
-    Animal(const std::string& _name, Kind _kind)
-        : kind(_kind), name(_name)
-    {}
+protected:
+    Animal(const std::string &_name, Kind _kind) : kind(_kind), name(_name) {}
 };
 
-struct Dog : Animal
-{
+struct Dog : Animal {
     explicit Dog(const std::string &_name, Kind _kind = Kind::Dog) : Animal(_name, _kind) {}
     std::string bark() const { return name_of_kind(kind) + " " + name + " goes " + sound; }
     std::string sound = "WOOF!";
 };
 
-struct Labrador : Dog
-{
+struct Labrador : Dog {
     explicit Labrador(const std::string &_name, int _excitement = 9001)
         : Dog(_name, Kind::Labrador), excitement(_excitement) {}
     int excitement;
 };
 
-struct Chihuahua : Dog
-{
+struct Chihuahua : Dog {
     explicit Chihuahua(const std::string &_name) : Dog(_name, Kind::Chihuahua) {
         sound = "iyiyiyiyiyi";
     }
     std::string bark() const { return Dog::bark() + " and runs in circles"; }
 };
 
-struct Cat : Animal
-{
+struct Cat : Animal {
     explicit Cat(const std::string &_name, Kind _kind = Kind::Cat) : Animal(_name, _kind) {}
     std::string purr() const { return "mrowr"; }
 };
 
-struct Panther : Cat
-{
+struct Panther : Cat {
     explicit Panther(const std::string &_name) : Cat(_name, Kind::Panther) {}
     std::string purr() const { return "mrrrRRRRRR"; }
 };
 
-std::vector<std::unique_ptr<Animal>> create_zoo()
-{
+std::vector<std::unique_ptr<Animal>> create_zoo() {
     std::vector<std::unique_ptr<Animal>> ret;
     ret.emplace_back(new Labrador("Fido", 15000));
 
@@ -85,45 +82,51 @@ std::vector<std::unique_ptr<Animal>> create_zoo()
     return ret;
 }
 
-const std::type_info* Animal::type_of_kind(Kind kind)
-{
+const std::type_info *Animal::type_of_kind(Kind kind) {
     switch (kind) {
         case Kind::Unknown:
-        case Kind::Dog: break;
+        case Kind::Dog:
+            break;
 
-        case Kind::Labrador: return &typeid(Labrador);
-        case Kind::Chihuahua: return &typeid(Chihuahua);
+        case Kind::Labrador:
+            return &typeid(Labrador);
+        case Kind::Chihuahua:
+            return &typeid(Chihuahua);
 
         case Kind::LastDog:
-        case Kind::Cat: break;
-        case Kind::Panther: return &typeid(Panther);
-        case Kind::LastCat: break;
+        case Kind::Cat:
+            break;
+        case Kind::Panther:
+            return &typeid(Panther);
+        case Kind::LastCat:
+            break;
     }
 
-    if (kind >= Kind::Dog && kind <= Kind::LastDog) return &typeid(Dog);
-    if (kind >= Kind::Cat && kind <= Kind::LastCat) return &typeid(Cat);
+    if (kind >= Kind::Dog && kind <= Kind::LastDog)
+        return &typeid(Dog);
+    if (kind >= Kind::Cat && kind <= Kind::LastCat)
+        return &typeid(Cat);
     return nullptr;
 }
 
-std::string Animal::name_of_kind(Kind kind)
-{
+std::string Animal::name_of_kind(Kind kind) {
     std::string raw_name = type_of_kind(kind)->name();
     py::detail::clean_type_id(raw_name);
     return raw_name;
 }
 
 namespace pybind11 {
-    template <typename itype>
-    struct polymorphic_type_hook<itype, detail::enable_if_t<std::is_base_of<Animal, itype>::value>>
-    {
-        static const void *get(const itype *src, const std::type_info*& type)
-        { type = src ? Animal::type_of_kind(src->kind) : nullptr; return src; }
-    };
+template <typename itype>
+struct polymorphic_type_hook<itype, detail::enable_if_t<std::is_base_of<Animal, itype>::value>> {
+    static const void *get(const itype *src, const std::type_info *&type) {
+        type = src ? Animal::type_of_kind(src->kind) : nullptr;
+        return src;
+    }
+};
 } // namespace pybind11
 
 TEST_SUBMODULE(tagbased_polymorphic, m) {
-    py::class_<Animal>(m, "Animal")
-        .def_readonly("name", &Animal::name);
+    py::class_<Animal>(m, "Animal").def_readonly("name", &Animal::name);
     py::class_<Dog, Animal>(m, "Dog")
         .def(py::init<std::string>())
         .def_readwrite("sound", &Dog::sound)
@@ -134,9 +137,7 @@ TEST_SUBMODULE(tagbased_polymorphic, m) {
     py::class_<Chihuahua, Dog>(m, "Chihuahua")
         .def(py::init<std::string>())
         .def("bark", &Chihuahua::bark);
-    py::class_<Cat, Animal>(m, "Cat")
-        .def(py::init<std::string>())
-        .def("purr", &Cat::purr);
+    py::class_<Cat, Animal>(m, "Cat").def(py::init<std::string>()).def("purr", &Cat::purr);
     py::class_<Panther, Cat>(m, "Panther")
         .def(py::init<std::string>())
         .def("purr", &Panther::purr);
diff --git a/tests/test_thread.cpp b/tests/test_thread.cpp
index 19d91768b3..1536503b6b 100644
--- a/tests/test_thread.cpp
+++ b/tests/test_thread.cpp
@@ -10,20 +10,20 @@
 #include <pybind11/cast.h>
 #include <pybind11/pybind11.h>
 
+#include "pybind11_tests.h"
+
 #include <chrono>
 #include <thread>
 
-#include "pybind11_tests.h"
-
 namespace py = pybind11;
 
 namespace {
 
 struct IntStruct {
-    explicit IntStruct(int v) : value(v) {};
+    explicit IntStruct(int v) : value(v){};
     ~IntStruct() { value = -value; }
-    IntStruct(const IntStruct&) = default;
-    IntStruct& operator=(const IntStruct&) = default;
+    IntStruct(const IntStruct &) = default;
+    IntStruct &operator=(const IntStruct &) = default;
 
     int value;
 };
diff --git a/tests/test_virtual_functions.cpp b/tests/test_virtual_functions.cpp
index d98b57f174..ef16b6d806 100644
--- a/tests/test_virtual_functions.cpp
+++ b/tests/test_virtual_functions.cpp
@@ -7,13 +7,15 @@
     BSD-style license that can be found in the LICENSE file.
 */
 
-#include "pybind11_tests.h"
-#include "constructor_stats.h"
 #include <pybind11/functional.h>
+
+#include "constructor_stats.h"
+#include "pybind11_tests.h"
+
 #include <thread>
 
 /* This is an example class that we'll want to be able to extend from Python */
-class ExampleVirt  {
+class ExampleVirt {
 public:
     explicit ExampleVirt(int state) : state(state) { print_created(this, state); }
     ExampleVirt(const ExampleVirt &e) : state(e.state) { print_copy_created(this); }
@@ -25,7 +27,8 @@ class ExampleVirt  {
 
     virtual int run(int value) {
         py::print("Original implementation of "
-                  "ExampleVirt::run(state={}, value={}, str1={}, str2={})"_s.format(state, value, get_string1(), *get_string2()));
+                  "ExampleVirt::run(state={}, value={}, str1={}, str2={})"_s.format(
+                      state, value, get_string1(), *get_string2()));
         return state + value;
     }
 
@@ -33,8 +36,8 @@ class ExampleVirt  {
     virtual void pure_virtual() = 0;
 
     // Returning a reference/pointer to a type converted from python (numbers, strings, etc.) is a
-    // bit trickier, because the actual int& or std::string& or whatever only exists temporarily, so
-    // we have to handle it specially in the trampoline class (see below).
+    // bit trickier, because the actual int& or std::string& or whatever only exists temporarily,
+    // so we have to handle it specially in the trampoline class (see below).
     virtual const std::string &get_string1() { return str1; }
     virtual const std::string *get_string2() { return &str2; }
 
@@ -50,59 +53,53 @@ class PyExampleVirt : public ExampleVirt {
 
     int run(int value) override {
         /* Generate wrapping code that enables native function overloading */
-        PYBIND11_OVERRIDE(
-            int,         /* Return type */
-            ExampleVirt, /* Parent class */
-            run,         /* Name of function */
-            value        /* Argument(s) */
+        PYBIND11_OVERRIDE(int,         /* Return type */
+                          ExampleVirt, /* Parent class */
+                          run,         /* Name of function */
+                          value        /* Argument(s) */
         );
     }
 
     bool run_bool() override {
-        PYBIND11_OVERRIDE_PURE(
-            bool,         /* Return type */
-            ExampleVirt,  /* Parent class */
-            run_bool,     /* Name of function */
-                          /* This function has no arguments. The trailing comma
-                             in the previous line is needed for some compilers */
+        PYBIND11_OVERRIDE_PURE(bool,        /* Return type */
+                               ExampleVirt, /* Parent class */
+                               run_bool,    /* Name of function */
+                                            /* This function has no arguments. The trailing comma
+                                               in the previous line is needed for some compilers */
         );
     }
 
     void pure_virtual() override {
-        PYBIND11_OVERRIDE_PURE(
-            void,         /* Return type */
-            ExampleVirt,  /* Parent class */
-            pure_virtual, /* Name of function */
-                          /* This function has no arguments. The trailing comma
-                             in the previous line is needed for some compilers */
+        PYBIND11_OVERRIDE_PURE(void,         /* Return type */
+                               ExampleVirt,  /* Parent class */
+                               pure_virtual, /* Name of function */
+                                             /* This function has no arguments. The trailing comma
+                                                in the previous line is needed for some compilers */
         );
     }
 
     // We can return reference types for compatibility with C++ virtual interfaces that do so, but
     // note they have some significant limitations (see the documentation).
     const std::string &get_string1() override {
-        PYBIND11_OVERRIDE(
-            const std::string &, /* Return type */
-            ExampleVirt,         /* Parent class */
-            get_string1,         /* Name of function */
-                                 /* (no arguments) */
+        PYBIND11_OVERRIDE(const std::string &, /* Return type */
+                          ExampleVirt,         /* Parent class */
+                          get_string1,         /* Name of function */
+                                               /* (no arguments) */
         );
     }
 
     const std::string *get_string2() override {
-        PYBIND11_OVERRIDE(
-            const std::string *, /* Return type */
-            ExampleVirt,         /* Parent class */
-            get_string2,         /* Name of function */
-                                 /* (no arguments) */
+        PYBIND11_OVERRIDE(const std::string *, /* Return type */
+                          ExampleVirt,         /* Parent class */
+                          get_string2,         /* Name of function */
+                                               /* (no arguments) */
         );
     }
-
 };
 
 class NonCopyable {
 public:
-    NonCopyable(int a, int b) : value{new int(a*b)} { print_created(this, a, b); }
+    NonCopyable(int a, int b) : value{new int(a * b)} { print_created(this, a, b); }
     NonCopyable(NonCopyable &&o) noexcept {
         value = std::move(o.value);
         print_move_created(this);
@@ -126,14 +123,18 @@ class NonCopyable {
 // when it is not referenced elsewhere, but copied if it is still referenced.
 class Movable {
 public:
-    Movable(int a, int b) : value{a+b} { print_created(this, a, b); }
-    Movable(const Movable &m) { value = m.value; print_copy_created(this); }
+    Movable(int a, int b) : value{a + b} { print_created(this, a, b); }
+    Movable(const Movable &m) {
+        value = m.value;
+        print_copy_created(this);
+    }
     Movable(Movable &&m) noexcept {
         value = m.value;
         print_move_created(this);
     }
     std::string get_value() const { return std::to_string(value); }
     ~Movable() { print_destroyed(this); }
+
 private:
     int value;
 };
@@ -142,7 +143,7 @@ class NCVirt {
 public:
     virtual ~NCVirt() = default;
     NCVirt() = default;
-    NCVirt(const NCVirt&) = delete;
+    NCVirt(const NCVirt &) = delete;
     virtual NonCopyable get_noncopyable(int a, int b) { return NonCopyable(a, b); }
     virtual Movable get_movable(int a, int b) = 0;
 
@@ -165,7 +166,7 @@ struct Base {
     virtual std::string dispatch() const { return {}; };
     virtual ~Base() = default;
     Base() = default;
-    Base(const Base&) = delete;
+    Base(const Base &) = delete;
 };
 
 struct DispatchIssue : Base {
@@ -178,33 +179,33 @@ struct DispatchIssue : Base {
 // objects and send the result to the visitor functor
 struct AdderBase {
     struct Data {};
-    using DataVisitor = std::function<void (const Data&)>;
+    using DataVisitor = std::function<void(const Data &)>;
 
-    virtual void operator()(const Data& first, const Data& second, const DataVisitor& visitor) const = 0;
+    virtual void
+    operator()(const Data &first, const Data &second, const DataVisitor &visitor) const = 0;
     virtual ~AdderBase() = default;
     AdderBase() = default;
-    AdderBase(const AdderBase&) = delete;
+    AdderBase(const AdderBase &) = delete;
 };
 
 struct Adder : AdderBase {
-    void operator()(const Data& first, const Data& second, const DataVisitor& visitor) const override {
-        PYBIND11_OVERRIDE_PURE_NAME(void, AdderBase, "__call__", operator(), first, second, visitor);
+    void
+    operator()(const Data &first, const Data &second, const DataVisitor &visitor) const override {
+        PYBIND11_OVERRIDE_PURE_NAME(
+            void, AdderBase, "__call__", operator(), first, second, visitor);
     }
 };
 
-
 static void test_gil() {
     {
         py::gil_scoped_acquire lock;
         py::print("1st lock acquired");
-
     }
 
     {
         py::gil_scoped_acquire lock;
         py::print("2nd lock acquired");
     }
-
 }
 
 static void test_gil_from_thread() {
@@ -230,12 +231,12 @@ class test_override_cache_helper_trampoline : public test_override_cache_helper
     int func() override { PYBIND11_OVERRIDE(int, test_override_cache_helper, func); }
 };
 
-inline int test_override_cache(std::shared_ptr<test_override_cache_helper> const &instance) { return instance->func(); }
-
-
+inline int test_override_cache(std::shared_ptr<test_override_cache_helper> const &instance) {
+    return instance->func();
+}
 
-// Forward declaration (so that we can put the main tests here; the inherited virtual approaches are
-// rather long).
+// Forward declaration (so that we can put the main tests here; the inherited virtual approaches
+// are rather long).
 void initialize_inherited_virtuals(py::module_ &m);
 
 TEST_SUBMODULE(virtual_functions, m) {
@@ -247,11 +248,9 @@ TEST_SUBMODULE(virtual_functions, m) {
         .def("run_bool", &ExampleVirt::run_bool)
         .def("pure_virtual", &ExampleVirt::pure_virtual);
 
-    py::class_<NonCopyable>(m, "NonCopyable")
-        .def(py::init<int, int>());
+    py::class_<NonCopyable>(m, "NonCopyable").def(py::init<int, int>());
 
-    py::class_<Movable>(m, "Movable")
-        .def(py::init<int, int>());
+    py::class_<Movable>(m, "Movable").def(py::init<int, int>());
 
     // test_move_support
 #if !defined(__INTEL_COMPILER) && !defined(__CUDACC__) && !defined(__PGIC__)
@@ -264,7 +263,7 @@ TEST_SUBMODULE(virtual_functions, m) {
 #endif
 
     m.def("runExampleVirt", [](ExampleVirt *ex, int value) { return ex->run(value); });
-    m.def("runExampleVirtBool", [](ExampleVirt* ex) { return ex->run_bool(); });
+    m.def("runExampleVirtBool", [](ExampleVirt *ex) { return ex->run_bool(); });
     m.def("runExampleVirtVirtual", [](ExampleVirt *ex) { ex->pure_virtual(); });
 
     m.def("cstats_debug", &ConstructorStats::get<ExampleVirt>);
@@ -275,27 +274,25 @@ TEST_SUBMODULE(virtual_functions, m) {
     // that were not extended on the Python side
     struct A {
         A() = default;
-        A(const A&) = delete;
+        A(const A &) = delete;
         virtual ~A() = default;
         virtual void f() { py::print("A.f()"); }
     };
 
     struct PyA : A {
         PyA() { py::print("PyA.PyA()"); }
-        PyA(const PyA&) = delete;
+        PyA(const PyA &) = delete;
         ~PyA() override { py::print("PyA.~PyA()"); }
 
         void f() override {
             py::print("PyA.f()");
-            // This convolution just gives a `void`, but tests that PYBIND11_TYPE() works to protect
-            // a type containing a ,
+            // This convolution just gives a `void`, but tests that PYBIND11_TYPE() works to
+            // protect a type containing a ,
             PYBIND11_OVERRIDE(PYBIND11_TYPE(typename std::enable_if<true, void>::type), A, f);
         }
     };
 
-    py::class_<A, PyA>(m, "A")
-        .def(py::init<>())
-        .def("f", &A::f);
+    py::class_<A, PyA>(m, "A").def(py::init<>()).def("f", &A::f);
 
     m.def("call_f", [](A *a) { a->f(); });
 
@@ -303,14 +300,14 @@ TEST_SUBMODULE(virtual_functions, m) {
     // ... unless we explicitly request it, as in this example:
     struct A2 {
         A2() = default;
-        A2(const A2&) = delete;
+        A2(const A2 &) = delete;
         virtual ~A2() = default;
         virtual void f() { py::print("A2.f()"); }
     };
 
     struct PyA2 : A2 {
         PyA2() { py::print("PyA2.PyA2()"); }
-        PyA2(const PyA2&) = delete;
+        PyA2(const PyA2 &) = delete;
         ~PyA2() override { py::print("PyA2.~PyA2()"); }
         void f() override {
             py::print("PyA2.f()");
@@ -331,7 +328,7 @@ TEST_SUBMODULE(virtual_functions, m) {
         .def(py::init<>())
         .def("dispatch", &Base::dispatch);
 
-    m.def("dispatch_issue_go", [](const Base * b) { return b->dispatch(); });
+    m.def("dispatch_issue_go", [](const Base *b) { return b->dispatch(); });
 
     // test_recursive_dispatch_issue
     // #3357: Recursive dispatch fails to find python function override
@@ -339,31 +336,39 @@ TEST_SUBMODULE(virtual_functions, m) {
         .def(pybind11::init<>())
         .def("__call__", &AdderBase::operator());
 
-    pybind11::class_<AdderBase::Data>(m, "Data")
-        .def(pybind11::init<>());
-
-    m.def("add2", [](const AdderBase::Data& first, const AdderBase::Data& second,
-                     const AdderBase& adder, const AdderBase::DataVisitor& visitor) {
-        adder(first, second, visitor);
-    });
-
-    m.def("add3", [](const AdderBase::Data& first, const AdderBase::Data& second, const AdderBase::Data& third,
-                     const AdderBase& adder, const AdderBase::DataVisitor& visitor) {
-        adder(first, second, [&] (const AdderBase::Data& first_plus_second) {
-            adder(first_plus_second, third, visitor); // NOLINT(readability-suspicious-call-argument)
-        });
-    });
+    pybind11::class_<AdderBase::Data>(m, "Data").def(pybind11::init<>());
+
+    m.def("add2",
+          [](const AdderBase::Data &first,
+             const AdderBase::Data &second,
+             const AdderBase &adder,
+             const AdderBase::DataVisitor &visitor) { adder(first, second, visitor); });
+
+    m.def("add3",
+          [](const AdderBase::Data &first,
+             const AdderBase::Data &second,
+             const AdderBase::Data &third,
+             const AdderBase &adder,
+             const AdderBase::DataVisitor &visitor) {
+              adder(first, second, [&](const AdderBase::Data &first_plus_second) {
+                  adder(first_plus_second,
+                        third,
+                        visitor); // NOLINT(readability-suspicious-call-argument)
+              });
+          });
 
     // test_override_ref
     // #392/397: overriding reference-returning functions
     class OverrideTest {
     public:
-        struct A { std::string value = "hi"; };
+        struct A {
+            std::string value = "hi";
+        };
         std::string v;
         A a;
         explicit OverrideTest(const std::string &v) : v{v} {}
         OverrideTest() = default;
-        OverrideTest(const OverrideTest&) = delete;
+        OverrideTest(const OverrideTest &) = delete;
         virtual std::string str_value() { return v; }
         virtual std::string &str_ref() { return v; }
         virtual A A_value() { return a; }
@@ -374,14 +379,18 @@ TEST_SUBMODULE(virtual_functions, m) {
     class PyOverrideTest : public OverrideTest {
     public:
         using OverrideTest::OverrideTest;
-        std::string str_value() override { PYBIND11_OVERRIDE(std::string, OverrideTest, str_value); }
+        std::string str_value() override {
+            PYBIND11_OVERRIDE(std::string, OverrideTest, str_value);
+        }
         // Not allowed (uncommenting should hit a static_assert failure): we can't get a reference
         // to a python numeric value, since we only copy values in the numeric type caster:
-//      std::string &str_ref() override { PYBIND11_OVERRIDE(std::string &, OverrideTest, str_ref); }
+        //      std::string &str_ref() override { PYBIND11_OVERRIDE(std::string &, OverrideTest,
+        //      str_ref); }
         // But we can work around it like this:
     private:
         std::string _tmp;
         std::string str_ref_helper() { PYBIND11_OVERRIDE(std::string, OverrideTest, str_ref); }
+
     public:
         std::string &str_ref() override { return _tmp = str_ref_helper(); }
 
@@ -394,18 +403,19 @@ TEST_SUBMODULE(virtual_functions, m) {
     py::class_<OverrideTest, PyOverrideTest>(m, "OverrideTest")
         .def(py::init<const std::string &>())
         .def("str_value", &OverrideTest::str_value)
-//      .def("str_ref", &OverrideTest::str_ref)
+        //      .def("str_ref", &OverrideTest::str_ref)
         .def("A_value", &OverrideTest::A_value)
         .def("A_ref", &OverrideTest::A_ref);
 
-    py::class_<test_override_cache_helper, test_override_cache_helper_trampoline, std::shared_ptr<test_override_cache_helper>>(m, "test_override_cache_helper")
+    py::class_<test_override_cache_helper,
+               test_override_cache_helper_trampoline,
+               std::shared_ptr<test_override_cache_helper>>(m, "test_override_cache_helper")
         .def(py::init_alias<>())
         .def("func", &test_override_cache_helper::func);
 
     m.def("test_override_cache", test_override_cache);
 }
 
-
 // Inheriting virtual methods.  We do two versions here: the repeat-everything version and the
 // templated trampoline versions mentioned in docs/advanced.rst.
 //
@@ -414,93 +424,108 @@ TEST_SUBMODULE(virtual_functions, m) {
 // properly (pybind11, sensibly, doesn't allow us to bind the same C++ class to
 // multiple python classes).
 class A_Repeat {
-#define A_METHODS \
-public: \
-    virtual int unlucky_number() = 0; \
-    virtual std::string say_something(unsigned times) { \
-        std::string s = ""; \
-        for (unsigned i = 0; i < times; ++i) \
-            s += "hi"; \
-        return s; \
-    } \
-    std::string say_everything() { \
-        return say_something(1) + " " + std::to_string(unlucky_number()); \
+#define A_METHODS                                                                                 \
+public:                                                                                           \
+    virtual int unlucky_number() = 0;                                                             \
+    virtual std::string say_something(unsigned times) {                                           \
+        std::string s = "";                                                                       \
+        for (unsigned i = 0; i < times; ++i)                                                      \
+            s += "hi";                                                                            \
+        return s;                                                                                 \
+    }                                                                                             \
+    std::string say_everything() {                                                                \
+        return say_something(1) + " " + std::to_string(unlucky_number());                         \
     }
-A_METHODS
+    A_METHODS
     A_Repeat() = default;
-    A_Repeat(const A_Repeat&) = delete;
+    A_Repeat(const A_Repeat &) = delete;
     virtual ~A_Repeat() = default;
 };
 class B_Repeat : public A_Repeat {
-#define B_METHODS \
-public: \
-    int unlucky_number() override { return 13; } \
-    std::string say_something(unsigned times) override { \
-        return "B says hi " + std::to_string(times) + " times"; \
-    } \
+#define B_METHODS                                                                                 \
+public:                                                                                           \
+    int unlucky_number() override { return 13; }                                                  \
+    std::string say_something(unsigned times) override {                                          \
+        return "B says hi " + std::to_string(times) + " times";                                   \
+    }                                                                                             \
     virtual double lucky_number() { return 7.0; }
-B_METHODS
+    B_METHODS
 };
 class C_Repeat : public B_Repeat {
-#define C_METHODS \
-public: \
-    int unlucky_number() override { return 4444; } \
+#define C_METHODS                                                                                 \
+public:                                                                                           \
+    int unlucky_number() override { return 4444; }                                                \
     double lucky_number() override { return 888; }
-C_METHODS
+    C_METHODS
 };
 class D_Repeat : public C_Repeat {
 #define D_METHODS // Nothing overridden.
-D_METHODS
+    D_METHODS
 };
 
 // Base classes for templated inheritance trampolines.  Identical to the repeat-everything version:
 class A_Tpl {
     A_METHODS;
     A_Tpl() = default;
-    A_Tpl(const A_Tpl&) = delete;
+    A_Tpl(const A_Tpl &) = delete;
     virtual ~A_Tpl() = default;
 };
-class B_Tpl : public A_Tpl { B_METHODS };
-class C_Tpl : public B_Tpl { C_METHODS };
-class D_Tpl : public C_Tpl { D_METHODS };
-
+class B_Tpl : public A_Tpl {
+    B_METHODS
+};
+class C_Tpl : public B_Tpl {
+    C_METHODS
+};
+class D_Tpl : public C_Tpl {
+    D_METHODS
+};
 
 // Inheritance approach 1: each trampoline gets every virtual method (11 in total)
 class PyA_Repeat : public A_Repeat {
 public:
     using A_Repeat::A_Repeat;
     int unlucky_number() override { PYBIND11_OVERRIDE_PURE(int, A_Repeat, unlucky_number, ); }
-    std::string say_something(unsigned times) override { PYBIND11_OVERRIDE(std::string, A_Repeat, say_something, times); }
+    std::string say_something(unsigned times) override {
+        PYBIND11_OVERRIDE(std::string, A_Repeat, say_something, times);
+    }
 };
 class PyB_Repeat : public B_Repeat {
 public:
     using B_Repeat::B_Repeat;
     int unlucky_number() override { PYBIND11_OVERRIDE(int, B_Repeat, unlucky_number, ); }
-    std::string say_something(unsigned times) override { PYBIND11_OVERRIDE(std::string, B_Repeat, say_something, times); }
+    std::string say_something(unsigned times) override {
+        PYBIND11_OVERRIDE(std::string, B_Repeat, say_something, times);
+    }
     double lucky_number() override { PYBIND11_OVERRIDE(double, B_Repeat, lucky_number, ); }
 };
 class PyC_Repeat : public C_Repeat {
 public:
     using C_Repeat::C_Repeat;
     int unlucky_number() override { PYBIND11_OVERRIDE(int, C_Repeat, unlucky_number, ); }
-    std::string say_something(unsigned times) override { PYBIND11_OVERRIDE(std::string, C_Repeat, say_something, times); }
+    std::string say_something(unsigned times) override {
+        PYBIND11_OVERRIDE(std::string, C_Repeat, say_something, times);
+    }
     double lucky_number() override { PYBIND11_OVERRIDE(double, C_Repeat, lucky_number, ); }
 };
 class PyD_Repeat : public D_Repeat {
 public:
     using D_Repeat::D_Repeat;
     int unlucky_number() override { PYBIND11_OVERRIDE(int, D_Repeat, unlucky_number, ); }
-    std::string say_something(unsigned times) override { PYBIND11_OVERRIDE(std::string, D_Repeat, say_something, times); }
+    std::string say_something(unsigned times) override {
+        PYBIND11_OVERRIDE(std::string, D_Repeat, say_something, times);
+    }
     double lucky_number() override { PYBIND11_OVERRIDE(double, D_Repeat, lucky_number, ); }
 };
 
 // Inheritance approach 2: templated trampoline classes.
 //
 // Advantages:
-// - we have only 2 (template) class and 4 method declarations (one per virtual method, plus one for
-//   any override of a pure virtual method), versus 4 classes and 6 methods (MI) or 4 classes and 11
-//   methods (repeat).
-// - Compared to MI, we also don't have to change the non-trampoline inheritance to virtual, and can
+// - we have only 2 (template) class and 4 method declarations (one per virtual method, plus one
+// for
+//   any override of a pure virtual method), versus 4 classes and 6 methods (MI) or 4 classes and
+//   11 methods (repeat).
+// - Compared to MI, we also don't have to change the non-trampoline inheritance to virtual, and
+// can
 //   properly inherit constructors.
 //
 // Disadvantage:
@@ -513,7 +538,9 @@ class PyA_Tpl : public Base {
 public:
     using Base::Base; // Inherit constructors
     int unlucky_number() override { PYBIND11_OVERRIDE_PURE(int, Base, unlucky_number, ); }
-    std::string say_something(unsigned times) override { PYBIND11_OVERRIDE(std::string, Base, say_something, times); }
+    std::string say_something(unsigned times) override {
+        PYBIND11_OVERRIDE(std::string, Base, say_something, times);
+    }
 };
 template <class Base = B_Tpl>
 class PyB_Tpl : public PyA_Tpl<Base> {
@@ -523,8 +550,8 @@ class PyB_Tpl : public PyA_Tpl<Base> {
     int unlucky_number() override { PYBIND11_OVERRIDE(int, Base, unlucky_number, ); }
     double lucky_number() override { PYBIND11_OVERRIDE(double, Base, lucky_number, ); }
 };
-// Since C_Tpl and D_Tpl don't declare any new virtual methods, we don't actually need these (we can
-// use PyB_Tpl<C_Tpl> and PyB_Tpl<D_Tpl> for the trampoline classes instead):
+// Since C_Tpl and D_Tpl don't declare any new virtual methods, we don't actually need these (we
+// can use PyB_Tpl<C_Tpl> and PyB_Tpl<D_Tpl> for the trampoline classes instead):
 /*
 template <class Base = C_Tpl> class PyC_Tpl : public PyB_Tpl<Base> {
 public:
@@ -548,10 +575,8 @@ void initialize_inherited_virtuals(py::module_ &m) {
     py::class_<B_Repeat, A_Repeat, PyB_Repeat>(m, "B_Repeat")
         .def(py::init<>())
         .def("lucky_number", &B_Repeat::lucky_number);
-    py::class_<C_Repeat, B_Repeat, PyC_Repeat>(m, "C_Repeat")
-        .def(py::init<>());
-    py::class_<D_Repeat, C_Repeat, PyD_Repeat>(m, "D_Repeat")
-        .def(py::init<>());
+    py::class_<C_Repeat, B_Repeat, PyC_Repeat>(m, "C_Repeat").def(py::init<>());
+    py::class_<D_Repeat, C_Repeat, PyD_Repeat>(m, "D_Repeat").def(py::init<>());
 
     // test_
     // Method 2: Templated trampolines
@@ -563,11 +588,8 @@ void initialize_inherited_virtuals(py::module_ &m) {
     py::class_<B_Tpl, A_Tpl, PyB_Tpl<>>(m, "B_Tpl")
         .def(py::init<>())
         .def("lucky_number", &B_Tpl::lucky_number);
-    py::class_<C_Tpl, B_Tpl, PyB_Tpl<C_Tpl>>(m, "C_Tpl")
-        .def(py::init<>());
-    py::class_<D_Tpl, C_Tpl, PyB_Tpl<D_Tpl>>(m, "D_Tpl")
-        .def(py::init<>());
-
+    py::class_<C_Tpl, B_Tpl, PyB_Tpl<C_Tpl>>(m, "C_Tpl").def(py::init<>());
+    py::class_<D_Tpl, C_Tpl, PyB_Tpl<D_Tpl>>(m, "D_Tpl").def(py::init<>());
 
     // Fix issue #1454 (crash when acquiring/releasing GIL on another thread in Python 2.7)
     m.def("test_gil", &test_gil);
diff --git a/tools/check-style.sh b/tools/check-style.sh
deleted file mode 100755
index 6d832523a7..0000000000
--- a/tools/check-style.sh
+++ /dev/null
@@ -1,44 +0,0 @@
-#!/bin/bash
-#
-# Script to check include/test code for common pybind11 code style errors.
-#
-# This script currently checks for
-#
-# 1. missing space between keyword and parenthesis, e.g.: for(, if(, while(
-# 2. Missing space between right parenthesis and brace, e.g. 'for (...){'
-# 3. opening brace on its own line. It should always be on the same line as the
-#    if/while/for/do statement.
-#
-# Invoke as: tools/check-style.sh <filenames>
-#
-
-check_style_errors=0
-IFS=$'\n'
-
-
-found="$(grep '\<\(if\|for\|while\|catch\)(\|){' "$@" -rn --color=always)"
-if [ -n "$found" ]; then
-    echo -e '\033[31;01mError: found the following coding style problems:\033[0m'
-    check_style_errors=1
-    echo "${found//^/    /}"
-fi
-
-found="$(awk '
-function prefix(filename, lineno) {
-    return "    \033[35m" filename "\033[36m:\033[32m" lineno "\033[36m:\033[0m"
-}
-function mark(pattern, string) { sub(pattern, "\033[01;31m&\033[0m", string); return string }
-last && /^\s*{/ {
-    print prefix(FILENAME, FNR-1) mark("\\)\\s*$", last)
-    print prefix(FILENAME, FNR)   mark("^\\s*{", $0)
-    last=""
-}
-{ last = /(if|for|while|catch|switch)\s*\(.*\)\s*$/ ? $0 : "" }
-' "$(find include -type f)" "$@")"
-if [ -n "$found" ]; then
-    check_style_errors=1
-    echo -e '\033[31;01mError: braces should occur on the same line as the if/while/.. statement. Found issues in the following files:\033[0m'
-    echo "$found"
-fi
-
-exit $check_style_errors