diff --git a/compiler/rustc_ast_passes/src/feature_gate.rs b/compiler/rustc_ast_passes/src/feature_gate.rs
index 77dd4ccd64ef2..258692a982cf7 100644
--- a/compiler/rustc_ast_passes/src/feature_gate.rs
+++ b/compiler/rustc_ast_passes/src/feature_gate.rs
@@ -401,6 +401,11 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
let msg = "`#[doc(keyword)]` is meant for internal use only";
gate_feature_post!(self, rustdoc_internals, attr.span, msg);
}
+
+ if nested_meta.has_name(sym::tuple_variadic) {
+ let msg = "`#[doc(tuple_variadic)]` is meant for internal use only";
+ gate_feature_post!(self, rustdoc_internals, attr.span, msg);
+ }
}
}
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 5cc97d326d3d8..1d94130f22204 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -804,6 +804,37 @@ impl CheckAttrVisitor<'_> {
true
}
+ fn check_doc_tuple_variadic(&self, meta: &NestedMetaItem, hir_id: HirId) -> bool {
+ match self.tcx.hir().find(hir_id).and_then(|node| match node {
+ hir::Node::Item(item) => Some(&item.kind),
+ _ => None,
+ }) {
+ Some(ItemKind::Impl(ref i)) => {
+ if !matches!(&i.self_ty.kind, hir::TyKind::Tup([_])) {
+ self.tcx
+ .sess
+ .struct_span_err(
+ meta.span(),
+ "`#[doc(tuple_variadic)]` must be used on the first of a set of tuple trait impls with varying arity",
+ )
+ .emit();
+ return false;
+ }
+ }
+ _ => {
+ self.tcx
+ .sess
+ .struct_span_err(
+ meta.span(),
+ "`#[doc(keyword = \"...\")]` can only be used on impl blocks",
+ )
+ .emit();
+ return false;
+ }
+ }
+ true
+ }
+
/// Checks `#[doc(inline)]`/`#[doc(no_inline)]` attributes. Returns `true` if valid.
///
/// A doc inlining attribute is invalid if it is applied to a non-`use` item, or
@@ -1064,6 +1095,13 @@ impl CheckAttrVisitor<'_> {
is_valid = false
}
+ sym::tuple_variadic
+ if !self.check_attr_not_crate_level(meta, hir_id, "tuple_variadic")
+ || !self.check_doc_tuple_variadic(meta, hir_id) =>
+ {
+ is_valid = false
+ }
+
sym::html_favicon_url
| sym::html_logo_url
| sym::html_playground_url
@@ -1117,7 +1155,8 @@ impl CheckAttrVisitor<'_> {
| sym::no_inline
| sym::notable_trait
| sym::passes
- | sym::plugins => {}
+ | sym::plugins
+ | sym::tuple_variadic => {}
sym::test => {
if !self.check_test_attr(meta, hir_id) {
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index bcaf53639cc63..ce3efc036ae8e 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -1439,6 +1439,7 @@ symbols! {
tuple,
tuple_from_req,
tuple_indexing,
+ tuple_variadic,
two_phase,
ty,
type_alias_enum_variants,
diff --git a/library/core/src/clone.rs b/library/core/src/clone.rs
index 70f3fe853d97a..fd5624812f554 100644
--- a/library/core/src/clone.rs
+++ b/library/core/src/clone.rs
@@ -95,7 +95,6 @@ use crate::marker::Destruct;
///
/// * Function item types (i.e., the distinct types defined for each function)
/// * Function pointer types (e.g., `fn() -> i32`)
-/// * Tuple types, if each component also implements `Clone` (e.g., `()`, `(i32, bool)`)
/// * Closure types, if they capture no value from the environment
/// or if all such captured values implement `Clone` themselves.
/// Note that variables captured by shared reference always implement `Clone`
diff --git a/library/core/src/fmt/mod.rs b/library/core/src/fmt/mod.rs
index 63655ae8a240b..1c66089fad6e6 100644
--- a/library/core/src/fmt/mod.rs
+++ b/library/core/src/fmt/mod.rs
@@ -2313,29 +2313,46 @@ macro_rules! peel {
macro_rules! tuple {
() => ();
( $($name:ident,)+ ) => (
- #[stable(feature = "rust1", since = "1.0.0")]
- impl<$($name:Debug),+> Debug for ($($name,)+) where last_type!($($name,)+): ?Sized {
- #[allow(non_snake_case, unused_assignments)]
- fn fmt(&self, f: &mut Formatter<'_>) -> Result {
- let mut builder = f.debug_tuple("");
- let ($(ref $name,)+) = *self;
- $(
- builder.field(&$name);
- )+
-
- builder.finish()
+ maybe_tuple_doc! {
+ $($name)+ @
+ #[stable(feature = "rust1", since = "1.0.0")]
+ impl<$($name:Debug),+> Debug for ($($name,)+) where last_type!($($name,)+): ?Sized {
+ #[allow(non_snake_case, unused_assignments)]
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result {
+ let mut builder = f.debug_tuple("");
+ let ($(ref $name,)+) = *self;
+ $(
+ builder.field(&$name);
+ )+
+
+ builder.finish()
+ }
}
}
peel! { $($name,)+ }
)
}
+macro_rules! maybe_tuple_doc {
+ ($a:ident @ #[$meta:meta] $item:item) => {
+ #[cfg_attr(not(bootstrap), doc(tuple_variadic))]
+ #[doc = "This trait is implemented for tuples up to twelve items long."]
+ #[$meta]
+ $item
+ };
+ ($a:ident $($rest_a:ident)+ @ #[$meta:meta] $item:item) => {
+ #[doc(hidden)]
+ #[$meta]
+ $item
+ };
+}
+
macro_rules! last_type {
($a:ident,) => { $a };
($a:ident, $($rest_a:ident,)+) => { last_type!($($rest_a,)+) };
}
-tuple! { T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, }
+tuple! { E, D, C, B, A, Z, Y, X, W, V, U, T, }
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: Debug> Debug for [T] {
diff --git a/library/core/src/hash/mod.rs b/library/core/src/hash/mod.rs
index 3d168f62a09f5..2c152fe1b2c18 100644
--- a/library/core/src/hash/mod.rs
+++ b/library/core/src/hash/mod.rs
@@ -883,36 +883,53 @@ mod impls {
);
( $($name:ident)+) => (
- #[stable(feature = "rust1", since = "1.0.0")]
- impl<$($name: Hash),+> Hash for ($($name,)+) where last_type!($($name,)+): ?Sized {
- #[allow(non_snake_case)]
- #[inline]
- fn hash<S: Hasher>(&self, state: &mut S) {
- let ($(ref $name,)+) = *self;
- $($name.hash(state);)+
+ maybe_tuple_doc! {
+ $($name)+ @
+ #[stable(feature = "rust1", since = "1.0.0")]
+ impl<$($name: Hash),+> Hash for ($($name,)+) where last_type!($($name,)+): ?Sized {
+ #[allow(non_snake_case)]
+ #[inline]
+ fn hash<S: Hasher>(&self, state: &mut S) {
+ let ($(ref $name,)+) = *self;
+ $($name.hash(state);)+
+ }
}
}
);
}
+ macro_rules! maybe_tuple_doc {
+ ($a:ident @ #[$meta:meta] $item:item) => {
+ #[cfg_attr(not(bootstrap), doc(tuple_variadic))]
+ #[doc = "This trait is implemented for tuples up to twelve items long."]
+ #[$meta]
+ $item
+ };
+ ($a:ident $($rest_a:ident)+ @ #[$meta:meta] $item:item) => {
+ #[doc(hidden)]
+ #[$meta]
+ $item
+ };
+ }
+
macro_rules! last_type {
($a:ident,) => { $a };
($a:ident, $($rest_a:ident,)+) => { last_type!($($rest_a,)+) };
}
impl_hash_tuple! {}
- impl_hash_tuple! { A }
- impl_hash_tuple! { A B }
- impl_hash_tuple! { A B C }
- impl_hash_tuple! { A B C D }
- impl_hash_tuple! { A B C D E }
- impl_hash_tuple! { A B C D E F }
- impl_hash_tuple! { A B C D E F G }
- impl_hash_tuple! { A B C D E F G H }
- impl_hash_tuple! { A B C D E F G H I }
- impl_hash_tuple! { A B C D E F G H I J }
- impl_hash_tuple! { A B C D E F G H I J K }
- impl_hash_tuple! { A B C D E F G H I J K L }
+ impl_hash_tuple! { T }
+ impl_hash_tuple! { T B }
+ impl_hash_tuple! { T B C }
+ impl_hash_tuple! { T B C D }
+ impl_hash_tuple! { T B C D E }
+ impl_hash_tuple! { T B C D E F }
+ impl_hash_tuple! { T B C D E F G }
+ impl_hash_tuple! { T B C D E F G H }
+ impl_hash_tuple! { T B C D E F G H I }
+ impl_hash_tuple! { T B C D E F G H I J }
+ impl_hash_tuple! { T B C D E F G H I J K }
+ impl_hash_tuple! { T B C D E F G H I J K L }
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: Hash> Hash for [T] {
diff --git a/library/core/src/marker.rs b/library/core/src/marker.rs
index 4a90ef9545d68..2c57897956fcd 100644
--- a/library/core/src/marker.rs
+++ b/library/core/src/marker.rs
@@ -359,7 +359,6 @@ pub trait StructuralEq {
///
/// * Function item types (i.e., the distinct types defined for each function)
/// * Function pointer types (e.g., `fn() -> i32`)
-/// * Tuple types, if each component also implements `Copy` (e.g., `()`, `(i32, bool)`)
/// * Closure types, if they capture no value from the environment
/// or if all such captured values implement `Copy` themselves.
/// Note that variables captured by shared reference always implement `Copy`
diff --git a/library/core/src/primitive_docs.rs b/library/core/src/primitive_docs.rs
index 688ab63bf1366..00793f7f9204d 100644
--- a/library/core/src/primitive_docs.rs
+++ b/library/core/src/primitive_docs.rs
@@ -439,6 +439,27 @@ mod prim_char {}
#[stable(feature = "rust1", since = "1.0.0")]
mod prim_unit {}
+// Required to make auto trait impls render.
+// See src/librustdoc/passes/collect_trait_impls.rs:collect_trait_impls
+#[doc(hidden)]
+impl () {}
+
+// Fake impl that's only really used for docs.
+#[cfg(doc)]
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Clone for () {
+ fn clone(&self) -> Self {
+ loop {}
+ }
+}
+
+// Fake impl that's only really used for docs.
+#[cfg(doc)]
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Copy for () {
+ // empty
+}
+
#[doc(primitive = "pointer")]
#[doc(alias = "ptr")]
#[doc(alias = "*")]
@@ -893,13 +914,18 @@ mod prim_str {}
///
/// For more about tuples, see [the book](../book/ch03-02-data-types.html#the-tuple-type).
///
+// Hardcoded anchor in src/librustdoc/html/format.rs
+// linked to as `#trait-implementations-1`
/// # Trait implementations
///
-/// If every type inside a tuple implements one of the following traits, then a
-/// tuple itself also implements it.
+/// In this documentation the shorthand `(T₁, T₂, …, Tₙ)` is used to represent tuples of varying
+/// length. When that is used, any trait bound expressed on `T` applies to each element of the
+/// tuple independently. Note that this is a convenience notation to avoid repetitive
+/// documentation, not valid Rust syntax.
+///
+/// Due to a temporary restriction in Rust’s type system, the following traits are only
+/// implemented on tuples of arity 12 or less. In the future, this may change:
///
-/// * [`Clone`]
-/// * [`Copy`]
/// * [`PartialEq`]
/// * [`Eq`]
/// * [`PartialOrd`]
@@ -911,8 +937,21 @@ mod prim_str {}
/// [`Debug`]: fmt::Debug
/// [`Hash`]: hash::Hash
///
-/// Due to a temporary restriction in Rust's type system, these traits are only
-/// implemented on tuples of arity 12 or less. In the future, this may change.
+/// The following traits are implemented for tuples of any length. These traits have
+/// implementations that are automatically generated by the compiler, so are not limited by
+/// missing language features.
+///
+/// * [`Clone`]
+/// * [`Copy`]
+/// * [`Send`]
+/// * [`Sync`]
+/// * [`Unpin`]
+/// * [`UnwindSafe`]
+/// * [`RefUnwindSafe`]
+///
+/// [`Unpin`]: marker::Unpin
+/// [`UnwindSafe`]: panic::UnwindSafe
+/// [`RefUnwindSafe`]: panic::RefUnwindSafe
///
/// # Examples
///
@@ -949,6 +988,31 @@ mod prim_str {}
#[stable(feature = "rust1", since = "1.0.0")]
mod prim_tuple {}
+// Required to make auto trait impls render.
+// See src/librustdoc/passes/collect_trait_impls.rs:collect_trait_impls
+#[doc(hidden)]
+impl<T> (T,) {}
+
+// Fake impl that's only really used for docs.
+#[cfg(doc)]
+#[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(bootstrap), doc(tuple_variadic))]
+/// This trait is implemented on arbitrary-length tuples.
+impl<T: Clone> Clone for (T,) {
+ fn clone(&self) -> Self {
+ loop {}
+ }
+}
+
+// Fake impl that's only really used for docs.
+#[cfg(doc)]
+#[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(bootstrap), doc(tuple_variadic))]
+/// This trait is implemented on arbitrary-length tuples.
+impl<T: Copy> Copy for (T,) {
+ // empty
+}
+
#[doc(primitive = "f32")]
/// A 32-bit floating point type (specifically, the "binary32" type defined in IEEE 754-2008).
///
diff --git a/library/core/src/tuple.rs b/library/core/src/tuple.rs
index 181717f35bd25..ab3763cbc4196 100644
--- a/library/core/src/tuple.rs
+++ b/library/core/src/tuple.rs
@@ -19,75 +19,106 @@ macro_rules! tuple_impls {
};
// "Private" internal implementation
(@impl $( $T:ident )+) => {
- #[stable(feature = "rust1", since = "1.0.0")]
- impl<$($T:PartialEq),+> PartialEq for ($($T,)+)
- where
- last_type!($($T,)+): ?Sized
- {
- #[inline]
- fn eq(&self, other: &($($T,)+)) -> bool {
- $( ${ignore(T)} self.${index()} == other.${index()} )&&+
- }
- #[inline]
- fn ne(&self, other: &($($T,)+)) -> bool {
- $( ${ignore(T)} self.${index()} != other.${index()} )||+
+ maybe_tuple_doc! {
+ $($T)+ @
+ #[stable(feature = "rust1", since = "1.0.0")]
+ impl<$($T:PartialEq),+> PartialEq for ($($T,)+)
+ where
+ last_type!($($T,)+): ?Sized
+ {
+ #[inline]
+ fn eq(&self, other: &($($T,)+)) -> bool {
+ $( ${ignore(T)} self.${index()} == other.${index()} )&&+
+ }
+ #[inline]
+ fn ne(&self, other: &($($T,)+)) -> bool {
+ $( ${ignore(T)} self.${index()} != other.${index()} )||+
+ }
}
}
- #[stable(feature = "rust1", since = "1.0.0")]
- impl<$($T:Eq),+> Eq for ($($T,)+)
- where
- last_type!($($T,)+): ?Sized
- {}
+ maybe_tuple_doc! {
+ $($T)+ @
+ #[stable(feature = "rust1", since = "1.0.0")]
+ impl<$($T:Eq),+> Eq for ($($T,)+)
+ where
+ last_type!($($T,)+): ?Sized
+ {}
+ }
- #[stable(feature = "rust1", since = "1.0.0")]
- impl<$($T:PartialOrd + PartialEq),+> PartialOrd for ($($T,)+)
- where
- last_type!($($T,)+): ?Sized
- {
- #[inline]
- fn partial_cmp(&self, other: &($($T,)+)) -> Option<Ordering> {
- lexical_partial_cmp!($( ${ignore(T)} self.${index()}, other.${index()} ),+)
- }
- #[inline]
- fn lt(&self, other: &($($T,)+)) -> bool {
- lexical_ord!(lt, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
- }
- #[inline]
- fn le(&self, other: &($($T,)+)) -> bool {
- lexical_ord!(le, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
- }
- #[inline]
- fn ge(&self, other: &($($T,)+)) -> bool {
- lexical_ord!(ge, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
- }
- #[inline]
- fn gt(&self, other: &($($T,)+)) -> bool {
- lexical_ord!(gt, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
+ maybe_tuple_doc! {
+ $($T)+ @
+ #[stable(feature = "rust1", since = "1.0.0")]
+ impl<$($T:PartialOrd + PartialEq),+> PartialOrd for ($($T,)+)
+ where
+ last_type!($($T,)+): ?Sized
+ {
+ #[inline]
+ fn partial_cmp(&self, other: &($($T,)+)) -> Option<Ordering> {
+ lexical_partial_cmp!($( ${ignore(T)} self.${index()}, other.${index()} ),+)
+ }
+ #[inline]
+ fn lt(&self, other: &($($T,)+)) -> bool {
+ lexical_ord!(lt, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
+ }
+ #[inline]
+ fn le(&self, other: &($($T,)+)) -> bool {
+ lexical_ord!(le, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
+ }
+ #[inline]
+ fn ge(&self, other: &($($T,)+)) -> bool {
+ lexical_ord!(ge, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
+ }
+ #[inline]
+ fn gt(&self, other: &($($T,)+)) -> bool {
+ lexical_ord!(gt, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
+ }
}
}
- #[stable(feature = "rust1", since = "1.0.0")]
- impl<$($T:Ord),+> Ord for ($($T,)+)
- where
- last_type!($($T,)+): ?Sized
- {
- #[inline]
- fn cmp(&self, other: &($($T,)+)) -> Ordering {
- lexical_cmp!($( ${ignore(T)} self.${index()}, other.${index()} ),+)
+ maybe_tuple_doc! {
+ $($T)+ @
+ #[stable(feature = "rust1", since = "1.0.0")]
+ impl<$($T:Ord),+> Ord for ($($T,)+)
+ where
+ last_type!($($T,)+): ?Sized
+ {
+ #[inline]
+ fn cmp(&self, other: &($($T,)+)) -> Ordering {
+ lexical_cmp!($( ${ignore(T)} self.${index()}, other.${index()} ),+)
+ }
}
}
- #[stable(feature = "rust1", since = "1.0.0")]
- impl<$($T:Default),+> Default for ($($T,)+) {
- #[inline]
- fn default() -> ($($T,)+) {
- ($({ let x: $T = Default::default(); x},)+)
+ maybe_tuple_doc! {
+ $($T)+ @
+ #[stable(feature = "rust1", since = "1.0.0")]
+ impl<$($T:Default),+> Default for ($($T,)+) {
+ #[inline]
+ fn default() -> ($($T,)+) {
+ ($({ let x: $T = Default::default(); x},)+)
+ }
}
}
}
}
+// If this is a unary tuple, it adds a doc comment.
+// Otherwise, it hides the docs entirely.
+macro_rules! maybe_tuple_doc {
+ ($a:ident @ #[$meta:meta] $item:item) => {
+ #[cfg_attr(not(bootstrap), doc(tuple_variadic))]
+ #[doc = "This trait is implemented for tuples up to twelve items long."]
+ #[$meta]
+ $item
+ };
+ ($a:ident $($rest_a:ident)+ @ #[$meta:meta] $item:item) => {
+ #[doc(hidden)]
+ #[$meta]
+ $item
+ };
+}
+
// Constructs an expression that performs a lexical ordering using method $rel.
// The values are interleaved, so the macro invocation for
// `(a1, a2, a3) < (b1, b2, b3)` would be `lexical_ord!(lt, a1, b1, a2, b2,
@@ -125,4 +156,4 @@ macro_rules! last_type {
($a:ident, $($rest_a:ident,)+) => { last_type!($($rest_a,)+) };
}
-tuple_impls!(A B C D E F G H I J K L);
+tuple_impls!(E D C B A Z Y X W V U T);
diff --git a/library/std/src/primitive_docs.rs b/library/std/src/primitive_docs.rs
index 688ab63bf1366..00793f7f9204d 100644
--- a/library/std/src/primitive_docs.rs
+++ b/library/std/src/primitive_docs.rs
@@ -439,6 +439,27 @@ mod prim_char {}
#[stable(feature = "rust1", since = "1.0.0")]
mod prim_unit {}
+// Required to make auto trait impls render.
+// See src/librustdoc/passes/collect_trait_impls.rs:collect_trait_impls
+#[doc(hidden)]
+impl () {}
+
+// Fake impl that's only really used for docs.
+#[cfg(doc)]
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Clone for () {
+ fn clone(&self) -> Self {
+ loop {}
+ }
+}
+
+// Fake impl that's only really used for docs.
+#[cfg(doc)]
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Copy for () {
+ // empty
+}
+
#[doc(primitive = "pointer")]
#[doc(alias = "ptr")]
#[doc(alias = "*")]
@@ -893,13 +914,18 @@ mod prim_str {}
///
/// For more about tuples, see [the book](../book/ch03-02-data-types.html#the-tuple-type).
///
+// Hardcoded anchor in src/librustdoc/html/format.rs
+// linked to as `#trait-implementations-1`
/// # Trait implementations
///
-/// If every type inside a tuple implements one of the following traits, then a
-/// tuple itself also implements it.
+/// In this documentation the shorthand `(T₁, T₂, …, Tₙ)` is used to represent tuples of varying
+/// length. When that is used, any trait bound expressed on `T` applies to each element of the
+/// tuple independently. Note that this is a convenience notation to avoid repetitive
+/// documentation, not valid Rust syntax.
+///
+/// Due to a temporary restriction in Rust’s type system, the following traits are only
+/// implemented on tuples of arity 12 or less. In the future, this may change:
///
-/// * [`Clone`]
-/// * [`Copy`]
/// * [`PartialEq`]
/// * [`Eq`]
/// * [`PartialOrd`]
@@ -911,8 +937,21 @@ mod prim_str {}
/// [`Debug`]: fmt::Debug
/// [`Hash`]: hash::Hash
///
-/// Due to a temporary restriction in Rust's type system, these traits are only
-/// implemented on tuples of arity 12 or less. In the future, this may change.
+/// The following traits are implemented for tuples of any length. These traits have
+/// implementations that are automatically generated by the compiler, so are not limited by
+/// missing language features.
+///
+/// * [`Clone`]
+/// * [`Copy`]
+/// * [`Send`]
+/// * [`Sync`]
+/// * [`Unpin`]
+/// * [`UnwindSafe`]
+/// * [`RefUnwindSafe`]
+///
+/// [`Unpin`]: marker::Unpin
+/// [`UnwindSafe`]: panic::UnwindSafe
+/// [`RefUnwindSafe`]: panic::RefUnwindSafe
///
/// # Examples
///
@@ -949,6 +988,31 @@ mod prim_str {}
#[stable(feature = "rust1", since = "1.0.0")]
mod prim_tuple {}
+// Required to make auto trait impls render.
+// See src/librustdoc/passes/collect_trait_impls.rs:collect_trait_impls
+#[doc(hidden)]
+impl<T> (T,) {}
+
+// Fake impl that's only really used for docs.
+#[cfg(doc)]
+#[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(bootstrap), doc(tuple_variadic))]
+/// This trait is implemented on arbitrary-length tuples.
+impl<T: Clone> Clone for (T,) {
+ fn clone(&self) -> Self {
+ loop {}
+ }
+}
+
+// Fake impl that's only really used for docs.
+#[cfg(doc)]
+#[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(bootstrap), doc(tuple_variadic))]
+/// This trait is implemented on arbitrary-length tuples.
+impl<T: Copy> Copy for (T,) {
+ // empty
+}
+
#[doc(primitive = "f32")]
/// A 32-bit floating point type (specifically, the "binary32" type defined in IEEE 754-2008).
///
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index a82abe6692655..d4c38f34b5b11 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -500,7 +500,11 @@ pub(crate) fn build_impl(
for_,
items: trait_items,
polarity,
- kind: ImplKind::Normal,
+ kind: if utils::has_doc_flag(tcx, did, sym::tuple_variadic) {
+ ImplKind::TupleVaradic
+ } else {
+ ImplKind::Normal
+ },
}),
box merged_attrs,
cx,
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index f3070fb35f1d0..fd30691c32489 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1999,7 +1999,11 @@ fn clean_impl<'tcx>(
for_,
items,
polarity: tcx.impl_polarity(def_id),
- kind: ImplKind::Normal,
+ kind: if utils::has_doc_flag(tcx, def_id.to_def_id(), sym::tuple_variadic) {
+ ImplKind::TupleVaradic
+ } else {
+ ImplKind::Normal
+ },
});
Item::from_hir_id_and_parts(hir_id, None, kind, cx)
};
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 4605793d0df94..83ab9acd3005a 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -1750,7 +1750,7 @@ pub(crate) enum PrimitiveType {
Never,
}
-type SimplifiedTypes = FxHashMap<PrimitiveType, ArrayVec<SimplifiedType, 2>>;
+type SimplifiedTypes = FxHashMap<PrimitiveType, ArrayVec<SimplifiedType, 3>>;
impl PrimitiveType {
pub(crate) fn from_hir(prim: hir::PrimTy) -> PrimitiveType {
use ast::{FloatTy, IntTy, UintTy};
@@ -1839,10 +1839,10 @@ impl PrimitiveType {
//
// Either manually update this arrayvec at this point
// or start with a more complex refactoring.
- Tuple => [TupleSimplifiedType(2), TupleSimplifiedType(3)].into(),
+ Tuple => [TupleSimplifiedType(1), TupleSimplifiedType(2), TupleSimplifiedType(3)].into(),
Unit => single(TupleSimplifiedType(0)),
- RawPointer => [PtrSimplifiedType(Mutability::Not), PtrSimplifiedType(Mutability::Mut)].into(),
- Reference => [RefSimplifiedType(Mutability::Not), RefSimplifiedType(Mutability::Mut)].into(),
+ RawPointer => [PtrSimplifiedType(Mutability::Not), PtrSimplifiedType(Mutability::Mut)].into_iter().collect(),
+ Reference => [RefSimplifiedType(Mutability::Not), RefSimplifiedType(Mutability::Mut)].into_iter().collect(),
// FIXME: This will be wrong if we ever add inherent impls
// for function pointers.
Fn => ArrayVec::new(),
@@ -2394,6 +2394,7 @@ impl Impl {
pub(crate) enum ImplKind {
Normal,
Auto,
+ TupleVaradic,
Blanket(Box<Type>),
}
@@ -2406,6 +2407,10 @@ impl ImplKind {
matches!(self, ImplKind::Blanket(_))
}
+ pub(crate) fn is_tuple_variadic(&self) -> bool {
+ matches!(self, ImplKind::TupleVaradic)
+ }
+
pub(crate) fn as_blanket_ty(&self) -> Option<&Type> {
match self {
ImplKind::Blanket(ty) => Some(ty),
diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index b7789493df647..5520430b04302 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -713,6 +713,16 @@ fn primitive_link(
prim: clean::PrimitiveType,
name: &str,
cx: &Context<'_>,
+) -> fmt::Result {
+ primitive_link_fragment(f, prim, name, "", cx)
+}
+
+fn primitive_link_fragment(
+ f: &mut fmt::Formatter<'_>,
+ prim: clean::PrimitiveType,
+ name: &str,
+ fragment: &str,
+ cx: &Context<'_>,
) -> fmt::Result {
let m = &cx.cache();
let mut needs_termination = false;
@@ -723,7 +733,7 @@ fn primitive_link(
let len = if len == 0 { 0 } else { len - 1 };
write!(
f,
- "<a class=\"primitive\" href=\"{}primitive.{}.html\">",
+ "<a class=\"primitive\" href=\"{}primitive.{}.html{fragment}\">",
"../".repeat(len),
prim.as_sym()
)?;
@@ -754,7 +764,7 @@ fn primitive_link(
};
if let Some(mut loc) = loc {
loc.push_fmt(format_args!("primitive.{}.html", prim.as_sym()));
- write!(f, "<a class=\"primitive\" href=\"{}\">", loc.finish())?;
+ write!(f, "<a class=\"primitive\" href=\"{}{fragment}\">", loc.finish())?;
needs_termination = true;
}
}
@@ -1064,7 +1074,13 @@ impl clean::Impl {
write!(f, " for ")?;
}
- if let Some(ty) = self.kind.as_blanket_ty() {
+ if let clean::Type::Tuple(types) = &self.for_ &&
+ let [clean::Type::Generic(name)] = &types[..] &&
+ (self.kind.is_tuple_variadic() || self.kind.is_auto()) {
+ // Hardcoded anchor library/core/src/primitive_docs.rs
+ // Link should match `# Trait implementations`
+ primitive_link_fragment(f, PrimitiveType::Tuple, &format!("({name}₁, {name}₂, …, {name}ₙ)"), "#trait-implementations-1", cx)?;
+ } else if let Some(ty) = self.kind.as_blanket_ty() {
fmt_type(ty, f, use_absolute, cx)?;
} else {
fmt_type(&self.for_, f, use_absolute, cx)?;
diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index 51a2abc50bc2b..4fde63c99d4b9 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -552,7 +552,7 @@ impl FromWithTcx<clean::Impl> for Impl {
let trait_ = trait_.map(|path| clean::Type::Path { path }.into_tcx(tcx));
// FIXME: use something like ImplKind in JSON?
let (synthetic, blanket_impl) = match kind {
- clean::ImplKind::Normal => (false, None),
+ clean::ImplKind::Normal | clean::ImplKind::TupleVaradic => (false, None),
clean::ImplKind::Auto => (true, None),
clean::ImplKind::Blanket(ty) => (false, Some(*ty)),
};
diff --git a/src/test/rustdoc-ui/tuple-variadic-check.rs b/src/test/rustdoc-ui/tuple-variadic-check.rs
new file mode 100644
index 0000000000000..11ce2dbe28050
--- /dev/null
+++ b/src/test/rustdoc-ui/tuple-variadic-check.rs
@@ -0,0 +1,15 @@
+#![feature(rustdoc_internals)]
+
+trait Mine {}
+
+// This one is fine
+#[doc(tuple_variadic)]
+impl<T> Mine for (T,) {}
+
+trait Mine2 {}
+
+// This one is not
+#[doc(tuple_variadic)] //~ ERROR
+impl<T, U> Mine for (T,U) {}
+
+fn main() {}
diff --git a/src/test/rustdoc-ui/tuple-variadic-check.stderr b/src/test/rustdoc-ui/tuple-variadic-check.stderr
new file mode 100644
index 0000000000000..358d06d6a42dd
--- /dev/null
+++ b/src/test/rustdoc-ui/tuple-variadic-check.stderr
@@ -0,0 +1,8 @@
+error: `#[doc(tuple_variadic)]` must be used on the first of a set of tuple trait impls with varying arity
+ --> $DIR/tuple-variadic-check.rs:12:7
+ |
+LL | #[doc(tuple_variadic)]
+ | ^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/rustdoc/primitive-tuple-auto-trait.rs b/src/test/rustdoc/primitive-tuple-auto-trait.rs
new file mode 100644
index 0000000000000..71b0b07700958
--- /dev/null
+++ b/src/test/rustdoc/primitive-tuple-auto-trait.rs
@@ -0,0 +1,22 @@
+// compile-flags: --crate-type lib --edition 2018
+
+#![crate_name = "foo"]
+#![feature(rustdoc_internals)]
+
+// @has foo/primitive.tuple.html '//a[@class="primitive"]' 'tuple'
+// @has - '//span[@class="in-band"]' 'Primitive Type tuple'
+// @has - '//section[@id="main-content"]//div[@class="docblock"]//p' 'this is a test!'
+// @has - '//h2[@id="synthetic-implementations"]' 'Auto Trait Implementations'
+// @has - '//div[@id="synthetic-implementations-list"]//h3' 'Send'
+// @has - '//div[@id="synthetic-implementations-list"]//h3' 'Sync'
+#[doc(primitive = "tuple")]
+/// this is a test!
+///
+// Hardcoded anchor to header written in library/core/src/primitive_docs.rs
+// @has - '//h2[@id="trait-implementations-1"]' 'Trait implementations'
+/// # Trait implementations
+///
+/// This header is hard-coded in the HTML format linking for `#[doc(tuple_variadics)]`.
+/// To make sure it gets linked correctly, we need to make sure the hardcoded anchor
+/// in the code matches what rustdoc generates for the header.
+mod tuple_prim {}
diff --git a/src/test/rustdoc/primitive-tuple-variadic.rs b/src/test/rustdoc/primitive-tuple-variadic.rs
new file mode 100644
index 0000000000000..4fd6254f6740d
--- /dev/null
+++ b/src/test/rustdoc/primitive-tuple-variadic.rs
@@ -0,0 +1,18 @@
+// compile-flags: --crate-type lib --edition 2018
+
+#![crate_name = "foo"]
+#![feature(rustdoc_internals)]
+
+pub trait Foo {}
+
+// @has foo/trait.Foo.html
+// @has - '//section[@id="impl-Foo-for-(T%2C)"]/h3' 'impl<T> Foo for (T₁, T₂, …, Tₙ)'
+#[doc(tuple_variadic)]
+impl<T> Foo for (T,) {}
+
+pub trait Bar {}
+
+// @has foo/trait.Bar.html
+// @has - '//section[@id="impl-Bar-for-(U%2C)"]/h3' 'impl<U: Foo> Bar for (U₁, U₂, …, Uₙ)'
+#[doc(tuple_variadic)]
+impl<U: Foo> Bar for (U,) {}
diff --git a/src/test/rustdoc/primitive-unit-auto-trait.rs b/src/test/rustdoc/primitive-unit-auto-trait.rs
new file mode 100644
index 0000000000000..76182622ef5fb
--- /dev/null
+++ b/src/test/rustdoc/primitive-unit-auto-trait.rs
@@ -0,0 +1,14 @@
+// compile-flags: --crate-type lib --edition 2018
+
+#![crate_name = "foo"]
+#![feature(rustdoc_internals)]
+
+// @has foo/primitive.unit.html '//a[@class="primitive"]' 'unit'
+// @has - '//span[@class="in-band"]' 'Primitive Type unit'
+// @has - '//section[@id="main-content"]//div[@class="docblock"]//p' 'this is a test!'
+// @has - '//h2[@id="synthetic-implementations"]' 'Auto Trait Implementations'
+// @has - '//div[@id="synthetic-implementations-list"]//h3' 'impl Send for ()'
+// @has - '//div[@id="synthetic-implementations-list"]//h3' 'impl Sync for ()'
+#[doc(primitive = "unit")]
+/// this is a test!
+mod unit_prim {}
diff --git a/src/test/ui/feature-gates/feature-gate-rustdoc_internals.rs b/src/test/ui/feature-gates/feature-gate-rustdoc_internals.rs
index d2ff4f6200986..6a144412d0751 100644
--- a/src/test/ui/feature-gates/feature-gate-rustdoc_internals.rs
+++ b/src/test/ui/feature-gates/feature-gate-rustdoc_internals.rs
@@ -2,4 +2,9 @@
/// wonderful
mod foo {}
+trait Mine {}
+
+#[doc(tuple_variadic)] //~ ERROR: `#[doc(tuple_variadic)]` is meant for internal use only
+impl<T> Mine for (T,) {}
+
fn main() {}
diff --git a/src/test/ui/feature-gates/feature-gate-rustdoc_internals.stderr b/src/test/ui/feature-gates/feature-gate-rustdoc_internals.stderr
index e96461ac38acb..9fe08afd4f05e 100644
--- a/src/test/ui/feature-gates/feature-gate-rustdoc_internals.stderr
+++ b/src/test/ui/feature-gates/feature-gate-rustdoc_internals.stderr
@@ -7,6 +7,15 @@ LL | #[doc(keyword = "match")]
= note: see issue #90418 <https://github.com/rust-lang/rust/issues/90418> for more information
= help: add `#![feature(rustdoc_internals)]` to the crate attributes to enable
-error: aborting due to previous error
+error[E0658]: `#[doc(tuple_variadic)]` is meant for internal use only
+ --> $DIR/feature-gate-rustdoc_internals.rs:7:1
+ |
+LL | #[doc(tuple_variadic)]
+ | ^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: see issue #90418 <https://github.com/rust-lang/rust/issues/90418> for more information
+ = help: add `#![feature(rustdoc_internals)]` to the crate attributes to enable
+
+error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0658`.