diff --git a/stl/src/StlLCMapStringA.cpp b/stl/src/StlLCMapStringA.cpp
index 4b89ba36fb5..0829495a1d7 100644
--- a/stl/src/StlLCMapStringA.cpp
+++ b/stl/src/StlLCMapStringA.cpp
@@ -84,8 +84,8 @@ extern "C" int __cdecl __crtLCMapStringA(LPCWSTR LocaleName, DWORD dwMapFlags, L
 
             // do string mapping
             if (0
-                == __crtLCMapStringEx(
-                    LocaleName, dwMapFlags, inwbuffer.get(), inbuff_size, (LPWSTR) lpDestStr, cchDest)) {
+                == __crtLCMapStringEx(LocaleName, dwMapFlags, inwbuffer.get(), inbuff_size,
+                    reinterpret_cast<LPWSTR>(lpDestStr), cchDest)) {
                 return retval;
             }
         }
diff --git a/stl/src/_tolower.cpp b/stl/src/_tolower.cpp
index 28e1e1fa698..21d35f55a10 100644
--- a/stl/src/_tolower.cpp
+++ b/stl/src/_tolower.cpp
@@ -51,7 +51,7 @@ _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Tolower(int c, const _Ctypevec* ploc)
     }
 
     if (locale_name == nullptr) {
-        if ((c >= 'A') && (c <= 'Z')) {
+        if (c >= 'A' && c <= 'Z') {
             c = c + ('a' - 'A');
         }
 
@@ -74,11 +74,11 @@ _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Tolower(int c, const _Ctypevec* ploc)
     // convert int c to multibyte string
     if (ploc == nullptr ? _cpp_isleadbyte((c >> 8) & 0xff) : (ploc->_Table[(c >> 8) & 0xff] & _LEADBYTE) != 0) {
         inbuffer[0] = (c >> 8 & 0xff);
-        inbuffer[1] = (unsigned char) c;
+        inbuffer[1] = static_cast<unsigned char>(c);
         inbuffer[2] = 0;
         size        = 2;
     } else {
-        inbuffer[0] = (unsigned char) c;
+        inbuffer[0] = static_cast<unsigned char>(c);
         inbuffer[1] = 0;
         size        = 1;
     }
@@ -93,9 +93,9 @@ _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Tolower(int c, const _Ctypevec* ploc)
 
     // construct integer return value
     if (size == 1) {
-        return (int) outbuffer[0];
+        return static_cast<int>(outbuffer[0]);
     } else {
-        return (int) outbuffer[1] | ((int) outbuffer[0] << 8);
+        return static_cast<int>(outbuffer[1]) | (static_cast<int>(outbuffer[0]) << 8);
     }
 }
 
@@ -104,12 +104,12 @@ _CRTIMP2_PURE _Ctypevec __CLRCALL_PURE_OR_CDECL _Getctype() {
     _Ctypevec ctype;
 
     ctype._Page  = ___lc_codepage_func();
-    ctype._Table = (const short*) _calloc_crt(256, sizeof(*__pctype_func()));
-    if (ctype._Table != 0) {
-        memcpy((void*) ctype._Table, __pctype_func(), 256 * sizeof(*__pctype_func()));
+    ctype._Table = static_cast<const short*>(_calloc_crt(256, sizeof(*__pctype_func())));
+    if (ctype._Table != nullptr) {
+        memcpy(const_cast<short*>(ctype._Table), __pctype_func(), 256 * sizeof(*__pctype_func()));
         ctype._Delfl = 1;
     } else {
-        ctype._Table = (const short*) __pctype_func();
+        ctype._Table = reinterpret_cast<const short*>(__pctype_func());
         ctype._Delfl = 0;
     }
     ctype._LocaleName = ___lc_locale_name_func()[LC_COLLATE];
diff --git a/stl/src/_toupper.cpp b/stl/src/_toupper.cpp
index 2f776e8baed..e0cc01cc5af 100644
--- a/stl/src/_toupper.cpp
+++ b/stl/src/_toupper.cpp
@@ -49,7 +49,7 @@ _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Toupper(int c, const _Ctypevec* ploc)
     }
 
     if (locale_name == nullptr) {
-        if ((c >= 'a') && (c <= 'z')) {
+        if (c >= 'a' && c <= 'z') {
             c = c - ('a' - 'A');
         }
 
@@ -72,11 +72,11 @@ _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Toupper(int c, const _Ctypevec* ploc)
     // convert int c to multibyte string
     if (ploc == nullptr ? _cpp_isleadbyte((c >> 8) & 0xff) : (ploc->_Table[(c >> 8) & 0xff] & _LEADBYTE) != 0) {
         inbuffer[0] = (c >> 8 & 0xff);
-        inbuffer[1] = (unsigned char) c;
+        inbuffer[1] = static_cast<unsigned char>(c);
         inbuffer[2] = 0;
         size        = 2;
     } else {
-        inbuffer[0] = (unsigned char) c;
+        inbuffer[0] = static_cast<unsigned char>(c);
         inbuffer[1] = 0;
         size        = 1;
     }
@@ -91,9 +91,9 @@ _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Toupper(int c, const _Ctypevec* ploc)
 
     // construct integer return value
     if (size == 1) {
-        return (int) outbuffer[0];
+        return static_cast<int>(outbuffer[0]);
     } else {
-        return (int) outbuffer[1] | ((int) outbuffer[0] << 8);
+        return static_cast<int>(outbuffer[1]) | (static_cast<int>(outbuffer[0]) << 8);
     }
 }
 
diff --git a/stl/src/atomic.cpp b/stl/src/atomic.cpp
index 7a8a9792f64..b2c0eeb00ba 100644
--- a/stl/src/atomic.cpp
+++ b/stl/src/atomic.cpp
@@ -27,7 +27,7 @@ _CRTIMP2_PURE void __cdecl _Lock_shared_ptr_spin_lock() { // spin until _Shared_
 _CRTIMP2_PURE void __cdecl _Unlock_shared_ptr_spin_lock() { // release previously obtained lock
 #ifdef _M_ARM
     __dmb(_ARM_BARRIER_ISH);
-    __iso_volatile_store32((volatile int*) &_Shared_ptr_flag, 0);
+    __iso_volatile_store32(reinterpret_cast<volatile int*>(&_Shared_ptr_flag), 0);
 #else // _M_ARM
     _interlockedbittestandreset(&_Shared_ptr_flag, 0); // reset bit 0
 #endif // _M_ARM
diff --git a/stl/src/cthread.cpp b/stl/src/cthread.cpp
index f7277732120..99cee9b12e6 100644
--- a/stl/src/cthread.cpp
+++ b/stl/src/cthread.cpp
@@ -28,7 +28,7 @@ namespace {
     using _Thrd_callback_t = unsigned int(__stdcall*)(void*);
 
     unsigned int __stdcall _Thrd_runner(void* d) { // call thread function
-        _Thrd_binder b = *(_Thrd_binder*) d;
+        _Thrd_binder b = *static_cast<_Thrd_binder*>(d);
         _Mtx_lock(*b.mtx);
         *b.started = 1;
         _Cnd_signal(*b.cond);
@@ -59,7 +59,7 @@ int _Thrd_join(_Thrd_t thr, int* code) { // return exit code when thread termina
     }
 
     if (code) {
-        *code = (int) res;
+        *code = static_cast<int>(res);
     }
 
     return CloseHandle(thr._Hnd) == 0 ? _Thrd_error : _Thrd_success;
diff --git a/stl/src/filesys.cpp b/stl/src/filesys.cpp
index 9b018700b29..7a734059a48 100644
--- a/stl/src/filesys.cpp
+++ b/stl/src/filesys.cpp
@@ -114,7 +114,7 @@ _FS_DLL void* __CLRCALL_PURE_OR_CDECL _Open_dir(
     if (_Handle == INVALID_HANDLE_VALUE) { // report failure
         _Errno = ERROR_BAD_PATHNAME;
         *_Dest = L'\0';
-        return 0;
+        return nullptr;
     }
 
     // success, get first directory entry
@@ -129,7 +129,7 @@ _FS_DLL void* __CLRCALL_PURE_OR_CDECL _Open_dir(
 
         // no entries, release handle
         _Close_dir(_Handle);
-        return 0;
+        return nullptr;
     }
 
     // get file type and return handle
@@ -145,7 +145,7 @@ _FS_DLL bool __CLRCALL_PURE_OR_CDECL _Current_get(wchar_t (&_Dest)[_MAX_FILESYS_
 #ifdef _CRT_APP
     return false; // no support
 #else // _CRT_APP
-    return _wgetcwd(_Dest, _MAX_FILESYS_NAME) != 0;
+    return _wgetcwd(_Dest, _MAX_FILESYS_NAME) != nullptr;
 #endif // _CRT_APP
 }
 
@@ -161,7 +161,7 @@ _FS_DLL bool __CLRCALL_PURE_OR_CDECL _Current_set(const wchar_t* _Dirname) {
 
 _FS_DLL wchar_t* __CLRCALL_PURE_OR_CDECL _Symlink_get(wchar_t (&_Dest)[_MAX_FILESYS_NAME], const wchar_t*) {
     // get symlink -- DUMMY
-    _Dest[0] = wchar_t(0);
+    _Dest[0] = L'\0';
     return &_Dest[0];
 }
 
diff --git a/stl/src/fiopen.cpp b/stl/src/fiopen.cpp
index 84aaebe741b..f5e2892dfd1 100644
--- a/stl/src/fiopen.cpp
+++ b/stl/src/fiopen.cpp
@@ -64,21 +64,21 @@ FILE* _Xfiopen(const CharT* filename, ios_base::openmode mode, int prot) {
     }
 
     if (valid[n] == 0) {
-        return 0; // no valid mode
+        return nullptr; // no valid mode
     }
 
     if (norepflag && (mode & (ios_base::out | ios_base::app))
         && (fp = _Xfsopen(filename, 0, prot)) != nullptr) { // file must not exist, close and fail
         fclose(fp);
-        return 0;
+        return nullptr;
     }
 
     if (fp != nullptr && fclose(fp) != 0) {
-        return 0; // can't close after test open
+        return nullptr; // can't close after test open
     }
 
     if ((fp = _Xfsopen(filename, n, prot)) == nullptr) {
-        return 0; // open failed
+        return nullptr; // open failed
     }
 
     if (!atendflag || fseek(fp, 0, SEEK_END) == 0) {
@@ -86,7 +86,7 @@ FILE* _Xfiopen(const CharT* filename, ios_base::openmode mode, int prot) {
     }
 
     fclose(fp); // can't position at end
-    return 0;
+    return nullptr;
 }
 
 _CRTIMP2_PURE FILE* __CLRCALL_PURE_OR_CDECL _Fiopen(
diff --git a/stl/src/ios.cpp b/stl/src/ios.cpp
index 3082c1781a4..73c12428252 100644
--- a/stl/src/ios.cpp
+++ b/stl/src/ios.cpp
@@ -75,7 +75,7 @@ void __CLRCALL_PURE_OR_CDECL ios_base::_Ios_base_dtor(ios_base* _This) { // dest
 void __CLRCALL_PURE_OR_CDECL ios_base::_Addstd(ios_base* _This) { // add standard stream to destructor list
     _BEGIN_LOCK(_LOCK_STREAM)
     for (_This->_Stdstr = 1; _This->_Stdstr < _Nstdstr; ++_This->_Stdstr) {
-        if (stdstr[_This->_Stdstr] == 0 || stdstr[_This->_Stdstr] == _This) {
+        if (stdstr[_This->_Stdstr] == nullptr || stdstr[_This->_Stdstr] == _This) {
             break; // found a candidate
         }
     }
diff --git a/stl/src/locale.cpp b/stl/src/locale.cpp
index 6f9b336ae1b..75e6250b402 100644
--- a/stl/src/locale.cpp
+++ b/stl/src/locale.cpp
@@ -17,11 +17,6 @@
 
 _STD_BEGIN
 
-using _Traits  = char_traits<char>;
-using _Initer  = istreambuf_iterator<char, _Traits>;
-using _Outiter = ostreambuf_iterator<char, _Traits>;
-
-
 _MRTIMP2_PURE locale __CLRCALL_PURE_OR_CDECL locale::global(const locale& loc) { // change global locale
     locale _Oldglobal;
     _BEGIN_LOCK(_LOCK_LOCALE)
@@ -49,29 +44,31 @@ _MRTIMP2_PURE locale __CLRCALL_PURE_OR_CDECL locale::global(const locale& loc) {
 
 #if STDCPP_IMPLIB || !defined(_M_CEE_PURE)
 // facets associated with C categories
-#define ADDFAC(Facet, cat, ptrimp, ptrloc)                                            \
-    if ((_CATMASK(Facet::_Getcat()) & cat) == 0) {                                    \
-        ;                                                                             \
-    } else if (ptrloc == nullptr) {                                                   \
-        ptrimp->_Addfac(new Facet(lobj), Facet::id);                                  \
-    } else {                                                                          \
-        ptrimp->_Addfac((locale::facet*) &_STD use_facet<Facet>(*ptrloc), Facet::id); \
+#define ADDFAC(Facet, cat, ptrimp, ptrloc)                                                                  \
+    if ((_CATMASK(Facet::_Getcat()) & cat) == 0) {                                                          \
+        ;                                                                                                   \
+    } else if (ptrloc == nullptr) {                                                                         \
+        ptrimp->_Addfac(new Facet(lobj), Facet::id);                                                        \
+    } else {                                                                                                \
+        ptrimp->_Addfac(                                                                                    \
+            const_cast<locale::facet*>(static_cast<const locale::facet*>(&_STD use_facet<Facet>(*ptrloc))), \
+            Facet::id);                                                                                     \
     }
 
-using _T1 = ctype<char>;
-using _T2 = num_get<char, _Initer>;
-using _T3 = num_put<char, _Outiter>;
-using _T4 = numpunct<char>;
-using _T5 = codecvt<char, char, _Mbstatet>;
+using _Tc1 = ctype<char>;
+using _Tc2 = num_get<char>;
+using _Tc3 = num_put<char>;
+using _Tc4 = numpunct<char>;
+using _Tc5 = codecvt<char, char, _Mbstatet>;
 // others moved to wlocale and xlocale to ease subsetting
 
 locale::_Locimp* __CLRCALL_OR_CDECL locale::_Locimp::_Makeloc(
     const _Locinfo& lobj, locale::category cat, _Locimp* ptrimp, const locale* ptrloc) { // setup a new locale
-    ADDFAC(_T1, cat, ptrimp, ptrloc);
-    ADDFAC(_T2, cat, ptrimp, ptrloc);
-    ADDFAC(_T3, cat, ptrimp, ptrloc);
-    ADDFAC(_T4, cat, ptrimp, ptrloc);
-    ADDFAC(_T5, cat, ptrimp, ptrloc);
+    ADDFAC(_Tc1, cat, ptrimp, ptrloc);
+    ADDFAC(_Tc2, cat, ptrimp, ptrloc);
+    ADDFAC(_Tc3, cat, ptrimp, ptrloc);
+    ADDFAC(_Tc4, cat, ptrimp, ptrloc);
+    ADDFAC(_Tc5, cat, ptrimp, ptrloc);
     _Locimp::_Makexloc(lobj, cat, ptrimp, ptrloc);
     _Locimp::_Makewloc(lobj, cat, ptrimp, ptrloc);
 #ifdef _NATIVE_WCHAR_T_DEFINED
@@ -91,10 +88,11 @@ void __CLRCALL_PURE_OR_CDECL locale::_Locimp::_Locimp_ctor(
     } else { // lock to keep facets from disappearing
         _BEGIN_LOCK(_LOCK_LOCALE)
         if (0 < _This->_Facetcount) { // copy over nonempty facet vector
-            if ((_This->_Facetvec = (locale::facet**) _malloc_crt(_This->_Facetcount * sizeof(locale::facet*)))
-                == nullptr) { // report no memory
+            _This->_Facetvec = static_cast<locale::facet**>(_malloc_crt(_This->_Facetcount * sizeof(locale::facet*)));
+            if (_This->_Facetvec == nullptr) { // report no memory
                 _Xbad_alloc();
             }
+
             for (size_t count = _This->_Facetcount; 0 < count;) { // copy over facet pointers
                 locale::facet* ptrfac = imp._Facetvec[--count];
                 if ((_This->_Facetvec[count] = ptrfac) != nullptr) {
@@ -119,7 +117,8 @@ void __CLRCALL_PURE_OR_CDECL locale::_Locimp::_Locimp_Addfac(
             count = MINCAT;
         }
 
-        locale::facet** ptrnewvec = (locale::facet**) _realloc_crt(_This->_Facetvec, count * sizeof(locale::facet**));
+        locale::facet** ptrnewvec =
+            static_cast<locale::facet**>(_realloc_crt(_This->_Facetvec, count * sizeof(locale::facet**)));
         if (ptrnewvec == nullptr) { // report no memory
             _Xbad_alloc();
         }
diff --git a/stl/src/locale0.cpp b/stl/src/locale0.cpp
index 144bcef20ab..46a6f679fe3 100644
--- a/stl/src/locale0.cpp
+++ b/stl/src/locale0.cpp
@@ -79,7 +79,7 @@ _STD_END
 _EXTERN_C
 
 void __CLRCALL_OR_CDECL _Deletegloballocale(void* ptr) { // delete a global locale reference
-    std::locale::_Locimp* locptr = *(std::locale::_Locimp**) ptr;
+    std::locale::_Locimp* locptr = *static_cast<std::locale::_Locimp**>(ptr);
     if (locptr != nullptr) {
         delete locptr->_Decref();
     }
@@ -116,7 +116,7 @@ _MRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL std::locale::_Setgloballocale(void* p
         _atexit_m_appdomain(tidy_global);
 #endif
     }
-    global_locale = (std::locale::_Locimp*) ptr;
+    global_locale = static_cast<std::locale::_Locimp*>(ptr);
 }
 
 __PURE_APPDOMAIN_GLOBAL static locale classic_locale(_Noinit); // "C" locale object, uninitialized
@@ -213,4 +213,4 @@ void __CLRCALL_PURE_OR_CDECL _Locinfo::_Locinfo_dtor(_Locinfo* pLocinfo) { // de
 }
 _STD_END
 
-#endif // !STDCPP_IMPLIB
+#endif // !STDCPP_IMPLIB || defined(_M_CEE_PURE)
diff --git a/stl/src/mutex.cpp b/stl/src/mutex.cpp
index 72f32365ff0..79ca2067e08 100644
--- a/stl/src/mutex.cpp
+++ b/stl/src/mutex.cpp
@@ -67,10 +67,11 @@ void _Mtx_destroy_in_situ(_Mtx_t mtx) { // destroy mutex in situ
 }
 
 int _Mtx_init(_Mtx_t* mtx, int type) { // initialize mutex
-    _Mtx_t mutex;
-    *mtx = 0;
+    *mtx = nullptr;
 
-    if ((mutex = static_cast<_Mtx_t>(_calloc_crt(1, sizeof(struct _Mtx_internal_imp_t)))) == 0) {
+    _Mtx_t mutex = static_cast<_Mtx_t>(_calloc_crt(1, sizeof(_Mtx_internal_imp_t)));
+
+    if (mutex == nullptr) {
         return _Thrd_nomem; // report alloc failed
     }
 
@@ -98,7 +99,7 @@ static int mtx_do_lock(_Mtx_t mtx, const xtime* target) { // lock mutex
         return _Thrd_success;
     } else { // handle timed or recursive mutex
         int res = WAIT_TIMEOUT;
-        if (target == 0) { // no target --> plain wait (i.e. infinite timeout)
+        if (target == nullptr) { // no target --> plain wait (i.e. infinite timeout)
             if (mtx->thread_id != static_cast<long>(GetCurrentThreadId())) {
                 mtx->_get_cs()->lock();
             }
@@ -149,7 +150,7 @@ static int mtx_do_lock(_Mtx_t mtx, const xtime* target) { // lock mutex
             return _Thrd_success;
 
         case WAIT_TIMEOUT:
-            if (target == 0 || (target->sec == 0 && target->nsec == 0)) {
+            if (target == nullptr || (target->sec == 0 && target->nsec == 0)) {
                 return _Thrd_busy;
             } else {
                 return _Thrd_timedout;
@@ -173,7 +174,7 @@ int _Mtx_unlock(_Mtx_t mtx) { // unlock mutex
 }
 
 int _Mtx_lock(_Mtx_t mtx) { // lock mutex
-    return mtx_do_lock(mtx, 0);
+    return mtx_do_lock(mtx, nullptr);
 }
 
 int _Mtx_trylock(_Mtx_t mtx) { // attempt to lock try_mutex
diff --git a/stl/src/parallel_algorithms.cpp b/stl/src/parallel_algorithms.cpp
index 5e7a5fc1254..c59577b7d53 100644
--- a/stl/src/parallel_algorithms.cpp
+++ b/stl/src/parallel_algorithms.cpp
@@ -82,7 +82,7 @@ namespace {
     void _Atomic_store_uint(volatile unsigned int* _Tgt, unsigned int _Value) {
         // atomic store of unsigned int, copied from <atomic>
 #if defined(_M_IX86) || defined(_M_X64)
-        _InterlockedExchange((volatile long*) _Tgt, static_cast<long>(_Value));
+        _InterlockedExchange(reinterpret_cast<volatile long*>(_Tgt), static_cast<long>(_Value));
 #else // architecture, ditto no ARM support
 #error Unsupported architecture
 #endif // architecture
diff --git a/stl/src/primitives.hpp b/stl/src/primitives.hpp
index 302d0daafd5..85eabcfb821 100644
--- a/stl/src/primitives.hpp
+++ b/stl/src/primitives.hpp
@@ -349,8 +349,8 @@ namespace Concurrency {
 #if defined _CRT_WINDOWS
         const size_t stl_critical_section_max_size        = sizeof(stl_critical_section_win7);
         const size_t stl_condition_variable_max_size      = sizeof(stl_condition_variable_win7);
-        const size_t stl_critical_section_max_alignment   = __alignof(stl_critical_section_win7);
-        const size_t stl_condition_variable_max_alignment = __alignof(stl_condition_variable_win7);
+        const size_t stl_critical_section_max_alignment   = alignof(stl_critical_section_win7);
+        const size_t stl_condition_variable_max_alignment = alignof(stl_condition_variable_win7);
 #elif defined _STL_CONCRT_SUPPORT
         const size_t stl_critical_section_max_size =
             __max(__max(sizeof(stl_critical_section_concrt), sizeof(stl_critical_section_vista)),
@@ -359,20 +359,20 @@ namespace Concurrency {
             __max(__max(sizeof(stl_condition_variable_concrt), sizeof(stl_condition_variable_vista)),
                 sizeof(stl_condition_variable_win7));
         const size_t stl_critical_section_max_alignment =
-            __max(__max(__alignof(stl_critical_section_concrt), __alignof(stl_critical_section_vista)),
-                __alignof(stl_critical_section_win7));
+            __max(__max(alignof(stl_critical_section_concrt), alignof(stl_critical_section_vista)),
+                alignof(stl_critical_section_win7));
         const size_t stl_condition_variable_max_alignment =
-            __max(__max(__alignof(stl_condition_variable_concrt), __alignof(stl_condition_variable_vista)),
-                __alignof(stl_condition_variable_win7));
+            __max(__max(alignof(stl_condition_variable_concrt), alignof(stl_condition_variable_vista)),
+                alignof(stl_condition_variable_win7));
 #else
         const size_t stl_critical_section_max_size =
             __max(sizeof(stl_critical_section_vista), sizeof(stl_critical_section_win7));
         const size_t stl_condition_variable_max_size =
             __max(sizeof(stl_condition_variable_vista), sizeof(stl_condition_variable_win7));
         const size_t stl_critical_section_max_alignment =
-            __max(__alignof(stl_critical_section_vista), __alignof(stl_critical_section_win7));
+            __max(alignof(stl_critical_section_vista), alignof(stl_critical_section_win7));
         const size_t stl_condition_variable_max_alignment =
-            __max(__alignof(stl_condition_variable_vista), __alignof(stl_condition_variable_win7));
+            __max(alignof(stl_condition_variable_vista), alignof(stl_condition_variable_win7));
 #endif
     } // namespace details
 } // namespace Concurrency
diff --git a/stl/src/raisehan.cpp b/stl/src/raisehan.cpp
index 6319197bca3..aa2f4bade2f 100644
--- a/stl/src/raisehan.cpp
+++ b/stl/src/raisehan.cpp
@@ -9,6 +9,6 @@
 #include <exception>
 _STD_BEGIN
 
-_Prhand _Raise_handler = 0; // define raise handler pointer
+_Prhand _Raise_handler = nullptr; // define raise handler pointer
 
 _STD_END
diff --git a/stl/src/stdhndlr.cpp b/stl/src/stdhndlr.cpp
index 82c64ac35db..3c0b777eba2 100644
--- a/stl/src/stdhndlr.cpp
+++ b/stl/src/stdhndlr.cpp
@@ -21,7 +21,7 @@ _CRTIMP2 new_handler __cdecl set_new_handler(new_handler pnew) noexcept { // rem
     _BEGIN_LOCK(_LOCK_MALLOC) // lock thread to ensure atomicity
     new_handler pold = _New_handler;
     _New_handler     = pnew;
-    _set_new_handler(pnew ? _New_handler_interface : 0);
+    _set_new_handler(pnew ? _New_handler_interface : nullptr);
     return pold;
     _END_LOCK()
 }
diff --git a/stl/src/wlocale.cpp b/stl/src/wlocale.cpp
index 508dae7f1bd..ea572750cd1 100644
--- a/stl/src/wlocale.cpp
+++ b/stl/src/wlocale.cpp
@@ -10,37 +10,33 @@ _STD_BEGIN
 #pragma warning(disable : 4074)
 #pragma init_seg(compiler)
 
-
-using _Wtraits  = char_traits<wchar_t>;
-using _Winiter  = istreambuf_iterator<wchar_t, _Wtraits>;
-using _Woutiter = ostreambuf_iterator<wchar_t, _Wtraits>;
-
 // facets associated with C categories
-#define ADDFAC(Facet, cat, ptrimp, ptrloc)                                            \
-    if ((_CATMASK(Facet::_Getcat()) & cat) == 0) {                                    \
-        ;                                                                             \
-    } else if (ptrloc == nullptr) {                                                   \
-        ptrimp->_Addfac(new Facet(lobj), Facet::id);                                  \
-    } else {                                                                          \
-        ptrimp->_Addfac((locale::facet*) &_STD use_facet<Facet>(*ptrloc), Facet::id); \
+#define ADDFAC(Facet, cat, ptrimp, ptrloc)                                                                  \
+    if ((_CATMASK(Facet::_Getcat()) & cat) == 0) {                                                          \
+        ;                                                                                                   \
+    } else if (ptrloc == nullptr) {                                                                         \
+        ptrimp->_Addfac(new Facet(lobj), Facet::id);                                                        \
+    } else {                                                                                                \
+        ptrimp->_Addfac(                                                                                    \
+            const_cast<locale::facet*>(static_cast<const locale::facet*>(&_STD use_facet<Facet>(*ptrloc))), \
+            Facet::id);                                                                                     \
     }
 
 // moved from locale to ease subsetting
 using _Tw1  = ctype<wchar_t>;
-using _Tw2  = num_get<wchar_t, _Winiter>;
-using _Tw3  = num_put<wchar_t, _Woutiter>;
+using _Tw2  = num_get<wchar_t>;
+using _Tw3  = num_put<wchar_t>;
 using _Tw4  = numpunct<wchar_t>;
 using _Tw5  = collate<wchar_t>;
 using _Tw6  = messages<wchar_t>;
-using _Tw7  = money_get<wchar_t, _Winiter>;
-using _Tw8  = money_put<wchar_t, _Woutiter>;
+using _Tw7  = money_get<wchar_t>;
+using _Tw8  = money_put<wchar_t>;
 using _Tw9  = moneypunct<wchar_t, false>;
 using _Tw10 = moneypunct<wchar_t, true>;
-using _Tw11 = time_get<wchar_t, _Winiter>;
-using _Tw12 = time_put<wchar_t, _Woutiter>;
+using _Tw11 = time_get<wchar_t>;
+using _Tw12 = time_put<wchar_t>;
 using _Tw13 = codecvt<wchar_t, char, _Mbstatet>;
-__PURE_APPDOMAIN_GLOBAL locale::id time_put<wchar_t, _Woutiter>::id(0);
-
+__PURE_APPDOMAIN_GLOBAL locale::id time_put<wchar_t>::id(0);
 
 void __CLRCALL_OR_CDECL locale::_Locimp::_Makewloc(const _Locinfo& lobj, locale::category cat, _Locimp* ptrimp,
     const locale* ptrloc) { // setup wide part of a new locale
@@ -60,40 +56,36 @@ void __CLRCALL_OR_CDECL locale::_Locimp::_Makewloc(const _Locinfo& lobj, locale:
 }
 
 #ifdef _NATIVE_WCHAR_T_DEFINED
-using _UShtraits  = char_traits<unsigned short>;
-using _UShiniter  = istreambuf_iterator<unsigned short, _UShtraits>;
-using _UShoutiter = ostreambuf_iterator<unsigned short, _UShtraits>;
-
 // moved from locale to ease subsetting
-using _Tush1  = ctype<unsigned short>;
-using _Tush2  = num_get<unsigned short, _UShiniter>;
-using _Tush3  = num_put<unsigned short, _UShoutiter>;
-using _Tush4  = numpunct<unsigned short>;
-using _Tush5  = collate<unsigned short>;
-using _Tush6  = messages<unsigned short>;
-using _Tush7  = money_get<unsigned short, _UShiniter>;
-using _Tush8  = money_put<unsigned short, _UShoutiter>;
-using _Tush9  = moneypunct<unsigned short, false>;
-using _Tush10 = moneypunct<unsigned short, true>;
-using _Tush11 = time_get<unsigned short, _UShiniter>;
-using _Tush12 = time_put<unsigned short, _UShoutiter>;
-using _Tush13 = codecvt<unsigned short, char, _Mbstatet>;
+using _Tu1  = ctype<unsigned short>;
+using _Tu2  = num_get<unsigned short>;
+using _Tu3  = num_put<unsigned short>;
+using _Tu4  = numpunct<unsigned short>;
+using _Tu5  = collate<unsigned short>;
+using _Tu6  = messages<unsigned short>;
+using _Tu7  = money_get<unsigned short>;
+using _Tu8  = money_put<unsigned short>;
+using _Tu9  = moneypunct<unsigned short, false>;
+using _Tu10 = moneypunct<unsigned short, true>;
+using _Tu11 = time_get<unsigned short>;
+using _Tu12 = time_put<unsigned short>;
+using _Tu13 = codecvt<unsigned short, char, _Mbstatet>;
 
 void __CLRCALL_OR_CDECL locale::_Locimp::_Makeushloc(const _Locinfo& lobj, locale::category cat, _Locimp* ptrimp,
     const locale* ptrloc) { // setup wide part of a new locale
-    ADDFAC(_Tush1, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush2, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush3, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush4, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush5, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush6, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush7, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush8, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush9, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush10, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush11, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush12, cat, ptrimp, ptrloc);
-    ADDFAC(_Tush13, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu1, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu2, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu3, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu4, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu5, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu6, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu7, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu8, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu9, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu10, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu11, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu12, cat, ptrimp, ptrloc);
+    ADDFAC(_Tu13, cat, ptrimp, ptrloc);
 }
 #endif // _NATIVE_WCHAR_T_DEFINED
 
diff --git a/stl/src/xdint.cpp b/stl/src/xdint.cpp
index 69a8af833e8..677f8d597bc 100644
--- a/stl/src/xdint.cpp
+++ b/stl/src/xdint.cpp
@@ -8,9 +8,8 @@
 _EXTERN_C_UNLESS_PURE
 
 short _Dint(double* px, short xexp) { // test and drop (scaled) fraction bits
-    _Dval* ps = (_Dval*) (char*) px;
-    unsigned short frac;
-    short xchar = (ps->_Sh[_D0] & _DMASK) >> _DOFF;
+    const auto ps = reinterpret_cast<_Dval*>(px);
+    short xchar   = (ps->_Sh[_D0] & _DMASK) >> _DOFF;
 
     if (xchar == _DMAX) {
         return (ps->_Sh[_D0] & _DFRAC) == 0 && ps->_Sh[_D1] == 0 && ps->_Sh[_D2] == 0 && ps->_Sh[_D3] == 0 ? _INFCODE
@@ -36,7 +35,7 @@ short _Dint(double* px, short xexp) { // test and drop (scaled) fraction bits
             0x0fff, 0x1fff, 0x3fff, 0x7fff};
         static const size_t sub[]          = {_D3, _D2, _D1, _D0};
 
-        frac = mask[xchar & 0xf];
+        unsigned short frac = mask[xchar & 0xf];
         xchar >>= 4;
         frac &= ps->_Sh[sub[xchar]];
         ps->_Sh[sub[xchar]] ^= frac;
diff --git a/stl/src/xdnorm.cpp b/stl/src/xdnorm.cpp
index e9a8587dde9..aa4bfbfcbaf 100644
--- a/stl/src/xdnorm.cpp
+++ b/stl/src/xdnorm.cpp
@@ -9,7 +9,7 @@ _EXTERN_C_UNLESS_PURE
 
 short _Dnorm(_Dval* ps) { // normalize double fraction
     short xchar;
-    unsigned short sign = (unsigned short) (ps->_Sh[_D0] & _DSIGN);
+    unsigned short sign = static_cast<unsigned short>(ps->_Sh[_D0] & _DSIGN);
 
     xchar = 1;
     if ((ps->_Sh[_D0] &= _DFRAC) != 0 || ps->_Sh[_D1] || ps->_Sh[_D2] || ps->_Sh[_D3]) { // nonzero, scale
@@ -20,15 +20,15 @@ short _Dnorm(_Dval* ps) { // normalize double fraction
             ps->_Sh[_D3] = 0;
         }
         for (; ps->_Sh[_D0] < 1 << _DOFF; --xchar) { // shift left by 1
-            ps->_Sh[_D0] = (unsigned short) (ps->_Sh[_D0] << 1 | ps->_Sh[_D1] >> 15);
-            ps->_Sh[_D1] = (unsigned short) (ps->_Sh[_D1] << 1 | ps->_Sh[_D2] >> 15);
-            ps->_Sh[_D2] = (unsigned short) (ps->_Sh[_D2] << 1 | ps->_Sh[_D3] >> 15);
+            ps->_Sh[_D0] = static_cast<unsigned short>(ps->_Sh[_D0] << 1 | ps->_Sh[_D1] >> 15);
+            ps->_Sh[_D1] = static_cast<unsigned short>(ps->_Sh[_D1] << 1 | ps->_Sh[_D2] >> 15);
+            ps->_Sh[_D2] = static_cast<unsigned short>(ps->_Sh[_D2] << 1 | ps->_Sh[_D3] >> 15);
             ps->_Sh[_D3] <<= 1;
         }
         for (; 1 << (_DOFF + 1) <= ps->_Sh[_D0]; ++xchar) { // shift right by 1
-            ps->_Sh[_D3] = (unsigned short) (ps->_Sh[_D3] >> 1 | ps->_Sh[_D2] << 15);
-            ps->_Sh[_D2] = (unsigned short) (ps->_Sh[_D2] >> 1 | ps->_Sh[_D1] << 15);
-            ps->_Sh[_D1] = (unsigned short) (ps->_Sh[_D1] >> 1 | ps->_Sh[_D0] << 15);
+            ps->_Sh[_D3] = static_cast<unsigned short>(ps->_Sh[_D3] >> 1 | ps->_Sh[_D2] << 15);
+            ps->_Sh[_D2] = static_cast<unsigned short>(ps->_Sh[_D2] >> 1 | ps->_Sh[_D1] << 15);
+            ps->_Sh[_D1] = static_cast<unsigned short>(ps->_Sh[_D1] >> 1 | ps->_Sh[_D0] << 15);
             ps->_Sh[_D0] >>= 1;
         }
         ps->_Sh[_D0] &= _DFRAC;
diff --git a/stl/src/xdscale.cpp b/stl/src/xdscale.cpp
index 9fa38e77c20..f6a6702dee2 100644
--- a/stl/src/xdscale.cpp
+++ b/stl/src/xdscale.cpp
@@ -8,13 +8,13 @@
 _EXTERN_C_UNLESS_PURE
 
 short _Dscale(double* px, long lexp) { // scale *px by 2^xexp with checking
-    _Dval* ps   = (_Dval*) (char*) px;
-    short xchar = (short) ((ps->_Sh[_D0] & _DMASK) >> _DOFF);
+    const auto ps = reinterpret_cast<_Dval*>(px);
+    short xchar   = static_cast<short>((ps->_Sh[_D0] & _DMASK) >> _DOFF);
 
     if (xchar == _DMAX) {
-        return (short) ((ps->_Sh[_D0] & _DFRAC) != 0 || ps->_Sh[_D1] != 0 || ps->_Sh[_D2] != 0 || ps->_Sh[_D3] != 0
-                            ? _NANCODE
-                            : _INFCODE);
+        return static_cast<short>(
+            (ps->_Sh[_D0] & _DFRAC) != 0 || ps->_Sh[_D1] != 0 || ps->_Sh[_D2] != 0 || ps->_Sh[_D3] != 0 ? _NANCODE
+                                                                                                        : _INFCODE);
     } else if (xchar == 0 && 0 < (xchar = _Dnorm(ps))) {
         return 0;
     }
@@ -23,12 +23,12 @@ short _Dscale(double* px, long lexp) { // scale *px by 2^xexp with checking
         *px = ps->_Sh[_D0] & _DSIGN ? -_Inf._Double : _Inf._Double;
         return _INFCODE;
     } else if (-xchar < lexp) { // finite result, repack
-        ps->_Sh[_D0] = (unsigned short) (ps->_Sh[_D0] & ~_DMASK | (lexp + xchar) << _DOFF);
+        ps->_Sh[_D0] = static_cast<unsigned short>(ps->_Sh[_D0] & ~_DMASK | (lexp + xchar) << _DOFF);
         return _FINITE;
     } else { // denormalized, scale
-        unsigned short sign = (unsigned short) (ps->_Sh[_D0] & _DSIGN);
+        unsigned short sign = static_cast<unsigned short>(ps->_Sh[_D0] & _DSIGN);
 
-        ps->_Sh[_D0] = (unsigned short) (1 << _DOFF | ps->_Sh[_D0] & _DFRAC);
+        ps->_Sh[_D0] = static_cast<unsigned short>(1 << _DOFF | ps->_Sh[_D0] & _DFRAC);
         lexp += xchar - 1;
         if (lexp < -(48 + 1 + _DOFF) || 0 <= lexp) { // certain underflow, return +/-0
             ps->_Sh[_D0] = sign;
@@ -37,7 +37,7 @@ short _Dscale(double* px, long lexp) { // scale *px by 2^xexp with checking
             ps->_Sh[_D3] = 0;
             return 0;
         } else { // nonzero, align fraction
-            short xexp         = (short) lexp;
+            short xexp         = static_cast<short>(lexp);
             unsigned short psx = 0;
 
             for (; xexp <= -16; xexp += 16) { // scale by words
@@ -47,11 +47,11 @@ short _Dscale(double* px, long lexp) { // scale *px by 2^xexp with checking
                 ps->_Sh[_D1] = ps->_Sh[_D0];
                 ps->_Sh[_D0] = 0;
             }
-            if ((xexp = (short) -xexp) != 0) { // scale by bits
+            if ((xexp = static_cast<short>(-xexp)) != 0) { // scale by bits
                 psx          = (ps->_Sh[_D3] << (16 - xexp)) | (psx != 0 ? 1 : 0);
-                ps->_Sh[_D3] = (unsigned short) (ps->_Sh[_D3] >> xexp | ps->_Sh[_D2] << (16 - xexp));
-                ps->_Sh[_D2] = (unsigned short) (ps->_Sh[_D2] >> xexp | ps->_Sh[_D1] << (16 - xexp));
-                ps->_Sh[_D1] = (unsigned short) (ps->_Sh[_D1] >> xexp | ps->_Sh[_D0] << (16 - xexp));
+                ps->_Sh[_D3] = static_cast<unsigned short>(ps->_Sh[_D3] >> xexp | ps->_Sh[_D2] << (16 - xexp));
+                ps->_Sh[_D2] = static_cast<unsigned short>(ps->_Sh[_D2] >> xexp | ps->_Sh[_D1] << (16 - xexp));
+                ps->_Sh[_D1] = static_cast<unsigned short>(ps->_Sh[_D1] >> xexp | ps->_Sh[_D0] << (16 - xexp));
                 ps->_Sh[_D0] >>= xexp;
             }
 
diff --git a/stl/src/xdtest.cpp b/stl/src/xdtest.cpp
index 0f680beb896..cc882cab591 100644
--- a/stl/src/xdtest.cpp
+++ b/stl/src/xdtest.cpp
@@ -8,12 +8,12 @@
 _EXTERN_C_UNLESS_PURE
 
 _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _Dtest(double* px) { // categorize *px
-    _Dval* ps = (_Dval*) (char*) px;
+    const auto ps = reinterpret_cast<_Dval*>(px);
 
     if ((ps->_Sh[_D0] & _DMASK) == _DMAX << _DOFF) {
-        return (short) ((ps->_Sh[_D0] & _DFRAC) != 0 || ps->_Sh[_D1] != 0 || ps->_Sh[_D2] != 0 || ps->_Sh[_D3] != 0
-                            ? _NANCODE
-                            : _INFCODE);
+        return static_cast<short>(
+            (ps->_Sh[_D0] & _DFRAC) != 0 || ps->_Sh[_D1] != 0 || ps->_Sh[_D2] != 0 || ps->_Sh[_D3] != 0 ? _NANCODE
+                                                                                                        : _INFCODE);
     } else if ((ps->_Sh[_D0] & ~_DSIGN) != 0 || ps->_Sh[_D1] != 0 || ps->_Sh[_D2] != 0 || ps->_Sh[_D3] != 0) {
         return (ps->_Sh[_D0] & _DMASK) == 0 ? _DENORM : _FINITE;
     } else {
@@ -22,11 +22,11 @@ _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _Dtest(double* px) { // categorize *
 }
 
 unsigned short* _Plsw(double* px) { // get pointer to lsw
-    return &((_Dval*) (char*) px)->_Sh[_Dg];
+    return &reinterpret_cast<_Dval*>(px)->_Sh[_Dg];
 }
 
 unsigned short* _Pmsw(double* px) { // get pointer to msw
-    return &((_Dval*) (char*) px)->_Sh[_D0];
+    return &reinterpret_cast<_Dval*>(px)->_Sh[_D0];
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xdunscal.cpp b/stl/src/xdunscal.cpp
index f2581633f5b..eb17a0f1bde 100644
--- a/stl/src/xdunscal.cpp
+++ b/stl/src/xdunscal.cpp
@@ -8,8 +8,8 @@
 _EXTERN_C_UNLESS_PURE
 
 short _Dunscale(short* pex, double* px) { // separate *px to 1/2 <= |frac| < 1 and 2^*pex
-    _Dval* ps   = (_Dval*) (char*) px;
-    short xchar = (ps->_Sh[_D0] & _DMASK) >> _DOFF;
+    const auto ps = reinterpret_cast<_Dval*>(px);
+    short xchar   = (ps->_Sh[_D0] & _DMASK) >> _DOFF;
 
     if (xchar == _DMAX) { // NaN or INF
         *pex = 0;
diff --git a/stl/src/xexp.cpp b/stl/src/xexp.cpp
index 8ae1e7bf3fe..a5ffe3bac6d 100644
--- a/stl/src/xexp.cpp
+++ b/stl/src/xexp.cpp
@@ -25,7 +25,7 @@ _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _Exp(
         return _INFCODE;
     } else { // xexp won't overflow
         double g   = *px * invln2;
-        short xexp = (short) (g + (g < 0.0 ? -0.5 : +0.5));
+        short xexp = static_cast<short>(g + (g < 0.0 ? -0.5 : +0.5));
 
         g = xexp;
         g = (*px - g * c1) - g * c2;
@@ -39,7 +39,7 @@ _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _Exp(
             *px = (w + g) / (w - g) * 2.0 * y;
             --xexp;
         }
-        return _Dscale(px, (long) xexp + eoff);
+        return _Dscale(px, static_cast<long>(xexp) + eoff);
     }
 }
 
diff --git a/stl/src/xfdint.cpp b/stl/src/xfdint.cpp
index 3f59537660c..d9966ff287b 100644
--- a/stl/src/xfdint.cpp
+++ b/stl/src/xfdint.cpp
@@ -8,9 +8,8 @@
 _EXTERN_C_UNLESS_PURE
 
 short _FDint(float* px, short xexp) { // test and drop (scaled) fraction bits
-    _Fval* ps = (_Fval*) (char*) px;
-    unsigned short frac;
-    short xchar = (ps->_Sh[_F0] & _FMASK) >> _FOFF;
+    const auto ps = reinterpret_cast<_Fval*>(px);
+    short xchar   = (ps->_Sh[_F0] & _FMASK) >> _FOFF;
 
     if (xchar == _FMAX) {
         return (ps->_Sh[_F0] & _FFRAC) == 0 && ps->_Sh[_F1] == 0 ? _INFCODE : _NANCODE;
@@ -33,7 +32,7 @@ short _FDint(float* px, short xexp) { // test and drop (scaled) fraction bits
             0x0fff, 0x1fff, 0x3fff, 0x7fff};
         static const size_t sub[]          = {_F1, _F0};
 
-        frac = mask[xchar & 0xf];
+        unsigned short frac = mask[xchar & 0xf];
         xchar >>= 4;
         frac &= ps->_Sh[sub[xchar]];
         ps->_Sh[sub[xchar]] ^= frac;
diff --git a/stl/src/xfdnorm.cpp b/stl/src/xfdnorm.cpp
index 752acfb0a73..c9f8322cc83 100644
--- a/stl/src/xfdnorm.cpp
+++ b/stl/src/xfdnorm.cpp
@@ -9,7 +9,7 @@ _EXTERN_C_UNLESS_PURE
 
 short _FDnorm(_Fval* ps) { // normalize float fraction
     short xchar;
-    unsigned short sign = (unsigned short) (ps->_Sh[_F0] & _FSIGN);
+    unsigned short sign = static_cast<unsigned short>(ps->_Sh[_F0] & _FSIGN);
 
     xchar = 1;
     if ((ps->_Sh[_F0] &= _FFRAC) != 0 || ps->_Sh[_F1]) { // nonzero, scale
@@ -20,11 +20,11 @@ short _FDnorm(_Fval* ps) { // normalize float fraction
         }
 
         for (; ps->_Sh[_F0] < 1 << _FOFF; --xchar) { // shift left by 1
-            ps->_Sh[_F0] = (unsigned short) (ps->_Sh[_F0] << 1 | ps->_Sh[_F1] >> 15);
+            ps->_Sh[_F0] = static_cast<unsigned short>(ps->_Sh[_F0] << 1 | ps->_Sh[_F1] >> 15);
             ps->_Sh[_F1] <<= 1;
         }
         for (; 1 << (_FOFF + 1) <= ps->_Sh[_F0]; ++xchar) { // shift right by 1
-            ps->_Sh[_F1] = (unsigned short) (ps->_Sh[_F1] >> 1 | ps->_Sh[_F0] << 15);
+            ps->_Sh[_F1] = static_cast<unsigned short>(ps->_Sh[_F1] >> 1 | ps->_Sh[_F0] << 15);
             ps->_Sh[_F0] >>= 1;
         }
         ps->_Sh[_F0] &= _FFRAC;
diff --git a/stl/src/xfdscale.cpp b/stl/src/xfdscale.cpp
index 29c9ff26446..b6492d3397f 100644
--- a/stl/src/xfdscale.cpp
+++ b/stl/src/xfdscale.cpp
@@ -8,11 +8,11 @@
 _EXTERN_C_UNLESS_PURE
 
 short _FDscale(float* px, long lexp) { // scale *px by 2^xexp with checking
-    _Fval* ps   = (_Fval*) (char*) px;
-    short xchar = (short) ((ps->_Sh[_F0] & _FMASK) >> _FOFF);
+    const auto ps = reinterpret_cast<_Fval*>(px);
+    short xchar   = static_cast<short>((ps->_Sh[_F0] & _FMASK) >> _FOFF);
 
     if (xchar == _FMAX) {
-        return (short) ((ps->_Sh[_F0] & _FFRAC) != 0 || ps->_Sh[_F1] != 0 ? _NANCODE : _INFCODE);
+        return static_cast<short>((ps->_Sh[_F0] & _FFRAC) != 0 || ps->_Sh[_F1] != 0 ? _NANCODE : _INFCODE);
     } else if (xchar == 0 && 0 < (xchar = _FDnorm(ps))) {
         return 0;
     }
@@ -21,19 +21,19 @@ short _FDscale(float* px, long lexp) { // scale *px by 2^xexp with checking
         *px = ps->_Sh[_F0] & _FSIGN ? -_FInf._Float : _FInf._Float;
         return _INFCODE;
     } else if (-xchar < lexp) { // finite result, repack
-        ps->_Sh[_F0] = (unsigned short) (ps->_Sh[_F0] & ~_FMASK | (lexp + xchar) << _FOFF);
+        ps->_Sh[_F0] = static_cast<unsigned short>(ps->_Sh[_F0] & ~_FMASK | (lexp + xchar) << _FOFF);
         return _FINITE;
     } else { // denormalized, scale
-        unsigned short sign = (unsigned short) (ps->_Sh[_F0] & _FSIGN);
+        unsigned short sign = static_cast<unsigned short>(ps->_Sh[_F0] & _FSIGN);
 
-        ps->_Sh[_F0] = (unsigned short) (1 << _FOFF | ps->_Sh[_F0] & _FFRAC);
+        ps->_Sh[_F0] = static_cast<unsigned short>(1 << _FOFF | ps->_Sh[_F0] & _FFRAC);
         lexp += xchar - 1;
         if (lexp < -(16 + 1 + _FOFF) || 0 <= lexp) { // underflow, return +/-0
             ps->_Sh[_F0] = sign;
             ps->_Sh[_F1] = 0;
             return 0;
         } else { // nonzero, align fraction
-            short xexp         = (short) lexp;
+            short xexp         = static_cast<short>(lexp);
             unsigned short psx = 0;
 
             if (xexp <= -16) { // scale by words
@@ -42,9 +42,9 @@ short _FDscale(float* px, long lexp) { // scale *px by 2^xexp with checking
                 ps->_Sh[_F0] = 0;
                 xexp += 16;
             }
-            if ((xexp = (short) -xexp) != 0) { // scale by bits
+            if ((xexp = static_cast<short>(-xexp)) != 0) { // scale by bits
                 psx          = (ps->_Sh[_F1] << (16 - xexp)) | (psx != 0 ? 1 : 0);
-                ps->_Sh[_F1] = (unsigned short) (ps->_Sh[_F1] >> xexp | ps->_Sh[_F0] << (16 - xexp));
+                ps->_Sh[_F1] = static_cast<unsigned short>(ps->_Sh[_F1] >> xexp | ps->_Sh[_F0] << (16 - xexp));
                 ps->_Sh[_F0] >>= xexp;
             }
 
diff --git a/stl/src/xfdtest.cpp b/stl/src/xfdtest.cpp
index af2e5c5cc76..c44e8c43530 100644
--- a/stl/src/xfdtest.cpp
+++ b/stl/src/xfdtest.cpp
@@ -8,10 +8,10 @@
 _EXTERN_C_UNLESS_PURE
 
 _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _FDtest(float* px) { // categorize *px
-    _Fval* ps = (_Fval*) (char*) px;
+    const auto ps = reinterpret_cast<_Fval*>(px);
 
     if ((ps->_Sh[_F0] & _FMASK) == _FMAX << _FOFF) {
-        return (short) ((ps->_Sh[_F0] & _FFRAC) != 0 || ps->_Sh[_F1] != 0 ? _NANCODE : _INFCODE);
+        return static_cast<short>((ps->_Sh[_F0] & _FFRAC) != 0 || ps->_Sh[_F1] != 0 ? _NANCODE : _INFCODE);
     } else if ((ps->_Sh[_F0] & ~_FSIGN) != 0 || ps->_Sh[_F1] != 0) {
         return (ps->_Sh[_F0] & _FMASK) == 0 ? _DENORM : _FINITE;
     } else {
@@ -20,11 +20,11 @@ _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _FDtest(float* px) { // categorize *
 }
 
 unsigned short* _FPlsw(float* px) { // get pointer to lsw
-    return &((_Fval*) (char*) px)->_Sh[_Fg];
+    return &reinterpret_cast<_Fval*>(px)->_Sh[_Fg];
 }
 
 unsigned short* _FPmsw(float* px) { // get pointer to msw
-    return &((_Fval*) (char*) px)->_Sh[_F0];
+    return &reinterpret_cast<_Fval*>(px)->_Sh[_F0];
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xfdunsca.cpp b/stl/src/xfdunsca.cpp
index 30489ae137f..1cea6634f0d 100644
--- a/stl/src/xfdunsca.cpp
+++ b/stl/src/xfdunsca.cpp
@@ -8,8 +8,8 @@
 _EXTERN_C_UNLESS_PURE
 
 short _FDunscale(short* pex, float* px) { // separate *px to 1/2 <= |frac| < 1 and 2^*pex
-    _Fval* ps   = (_Fval*) (char*) px;
-    short xchar = (ps->_Sh[_F0] & _FMASK) >> _FOFF;
+    const auto ps = reinterpret_cast<_Fval*>(px);
+    short xchar   = (ps->_Sh[_F0] & _FMASK) >> _FOFF;
 
     if (xchar == _FMAX) { // NaN or INF
         *pex = 0;
diff --git a/stl/src/xfexp.cpp b/stl/src/xfexp.cpp
index bd344ecfb07..8aec77d935b 100644
--- a/stl/src/xfexp.cpp
+++ b/stl/src/xfexp.cpp
@@ -24,10 +24,10 @@ _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _FExp(
         return _INFCODE;
     } else { // xexp won't overflow
         float g    = *px * invln2;
-        short xexp = (short) (g + (g < 0.0F ? -0.5F : +0.5F));
+        short xexp = static_cast<short>(g + (g < 0.0F ? -0.5F : +0.5F));
 
         g = xexp;
-        g = (float) ((*px - g * c1) - g * c2);
+        g = static_cast<float>((*px - g * c1) - g * c2);
         if (-_FEps._Float < g && g < _FEps._Float) {
             *px = y;
         } else { // g * g worth computing
@@ -38,7 +38,7 @@ _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _FExp(
             *px = (w + g) / (w - g) * 2.0F * y;
             --xexp;
         }
-        return _FDscale(px, (long) xexp + eoff);
+        return _FDscale(px, static_cast<long>(xexp) + eoff);
     }
 }
 
diff --git a/stl/src/xgetwctype.cpp b/stl/src/xgetwctype.cpp
index d12dc2f3b07..b3e444a2376 100644
--- a/stl/src/xgetwctype.cpp
+++ b/stl/src/xgetwctype.cpp
@@ -16,19 +16,19 @@ _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _Getwctype(wchar_t _Ch,
     const _Ctypevec* _Ctype) { // return character classification flags for _Ch
     _CRT_UNUSED(_Ctype);
     short _Mask;
-    return (short) (GetStringTypeW(CT_CTYPE1, &_Ch, 1, (LPWORD) &_Mask) == 0 ? 0 : _Mask);
+    return static_cast<short>(GetStringTypeW(CT_CTYPE1, &_Ch, 1, reinterpret_cast<LPWORD>(&_Mask)) == 0 ? 0 : _Mask);
 }
 
 _CRTIMP2_PURE const wchar_t* __CLRCALL_PURE_OR_CDECL _Getwctypes(const wchar_t* _First, const wchar_t* _Last,
     short* _Dest, const _Ctypevec* _Ctype) { // get mask sequence for elements in [_First, _Last)
     _CRT_UNUSED(_Ctype);
-    GetStringTypeW(CT_CTYPE1, _First, (int) (_Last - _First), (LPWORD) _Dest);
+    GetStringTypeW(CT_CTYPE1, _First, static_cast<int>(_Last - _First), reinterpret_cast<LPWORD>(_Dest));
     return _Last;
 }
 
 #ifdef MRTDLL
 _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _Getwctype(unsigned short _Ch, const _Ctypevec* _Ctype) {
-    return _Getwctype((wchar_t) _Ch, _Ctype);
+    return _Getwctype(static_cast<wchar_t>(_Ch), _Ctype);
 }
 
 _CRTIMP2_PURE const unsigned short* __CLRCALL_PURE_OR_CDECL _Getwctypes(
diff --git a/stl/src/xldint.cpp b/stl/src/xldint.cpp
index 6139497a449..45747c55d11 100644
--- a/stl/src/xldint.cpp
+++ b/stl/src/xldint.cpp
@@ -8,7 +8,7 @@
 _EXTERN_C_UNLESS_PURE
 
 short _LDint(long double* px, short xexp) { // test and drop (scaled) fraction bits -- 64-bit
-    return _Dint((double*) px, xexp);
+    return _Dint(reinterpret_cast<double*>(px), xexp);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xldscale.cpp b/stl/src/xldscale.cpp
index 541bf146be9..5bc6456b343 100644
--- a/stl/src/xldscale.cpp
+++ b/stl/src/xldscale.cpp
@@ -8,7 +8,7 @@
 _EXTERN_C_UNLESS_PURE
 
 short _LDscale(long double* px, long lexp) { // scale *px by 2^lexp with checking -- 64-bit
-    return _Dscale((double*) px, lexp);
+    return _Dscale(reinterpret_cast<double*>(px), lexp);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xldtest.cpp b/stl/src/xldtest.cpp
index 6fc5daf7827..796c06b9abf 100644
--- a/stl/src/xldtest.cpp
+++ b/stl/src/xldtest.cpp
@@ -8,15 +8,15 @@
 _EXTERN_C_UNLESS_PURE
 
 _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _LDtest(long double* px) { // categorize *px -- 64-bit
-    return _Dtest((double*) px);
+    return _Dtest(reinterpret_cast<double*>(px));
 }
 
 unsigned short* _LPlsw(long double* px) { // get pointer to lsw
-    return &((_Lval*) (char*) px)->_Sh[_L3];
+    return &reinterpret_cast<_Lval*>(px)->_Sh[_L3];
 }
 
 unsigned short* _LPmsw(long double* px) { // get pointer to msw
-    return &((_Lval*) (char*) px)->_Sh[_L0];
+    return &reinterpret_cast<_Lval*>(px)->_Sh[_L0];
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xldunsca.cpp b/stl/src/xldunsca.cpp
index 19aed391e6b..5f4d8d6b2af 100644
--- a/stl/src/xldunsca.cpp
+++ b/stl/src/xldunsca.cpp
@@ -8,7 +8,7 @@
 _EXTERN_C_UNLESS_PURE
 
 short _LDunscale(short* pex, long double* px) { // separate *px to 1/2 <= |frac| < 1 and 2^*pex -- 64-bit
-    return _Dunscale(pex, (double*) px);
+    return _Dunscale(pex, reinterpret_cast<double*>(px));
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xlexp.cpp b/stl/src/xlexp.cpp
index 46275afd763..1fd79d809e7 100644
--- a/stl/src/xlexp.cpp
+++ b/stl/src/xlexp.cpp
@@ -26,7 +26,7 @@ _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _LExp(
         return _INFCODE;
     } else { // xexp won't overflow
         long double g = *px * invln2;
-        short xexp    = (short) (g + (g < 0 ? -0.5L : +0.5L));
+        short xexp    = static_cast<short>(g + (g < 0 ? -0.5L : +0.5L));
 
         g = xexp;
         g = (*px - g * c1) - g * c2;
@@ -40,7 +40,7 @@ _CRTIMP2_PURE short __CLRCALL_PURE_OR_CDECL _LExp(
             *px = (w + g) / (w - g) * 2.0L * y;
             --xexp;
         }
-        return _LDscale(px, (long) xexp + eoff);
+        return _LDscale(px, static_cast<long>(xexp) + eoff);
     }
 }
 
diff --git a/stl/src/xlocale.cpp b/stl/src/xlocale.cpp
index 2c634d6ce48..24185c36d45 100644
--- a/stl/src/xlocale.cpp
+++ b/stl/src/xlocale.cpp
@@ -10,29 +10,27 @@ _STD_BEGIN
 #pragma warning(disable : 4074)
 #pragma init_seg(compiler)
 
-using _Traits  = char_traits<char>;
-using _Initer  = istreambuf_iterator<char, _Traits>;
-using _Outiter = ostreambuf_iterator<char, _Traits>;
-
 // facets associated with C categories
-#define ADDFAC(Facet, cat, ptrimp, ptrloc)                                            \
-    if ((_CATMASK(Facet::_Getcat()) & cat) == 0) {                                    \
-        ;                                                                             \
-    } else if (ptrloc == nullptr) {                                                   \
-        ptrimp->_Addfac(new Facet(lobj), Facet::id);                                  \
-    } else {                                                                          \
-        ptrimp->_Addfac((locale::facet*) &_STD use_facet<Facet>(*ptrloc), Facet::id); \
+#define ADDFAC(Facet, cat, ptrimp, ptrloc)                                                                  \
+    if ((_CATMASK(Facet::_Getcat()) & cat) == 0) {                                                          \
+        ;                                                                                                   \
+    } else if (ptrloc == nullptr) {                                                                         \
+        ptrimp->_Addfac(new Facet(lobj), Facet::id);                                                        \
+    } else {                                                                                                \
+        ptrimp->_Addfac(                                                                                    \
+            const_cast<locale::facet*>(static_cast<const locale::facet*>(&_STD use_facet<Facet>(*ptrloc))), \
+            Facet::id);                                                                                     \
     }
 
 // moved from locale to ease subsetting
 using _Tx1 = collate<char>;
 using _Tx2 = messages<char>;
-using _Tx3 = money_get<char, _Initer>;
-using _Tx4 = money_put<char, _Outiter>;
+using _Tx3 = money_get<char>;
+using _Tx4 = money_put<char>;
 using _Tx5 = moneypunct<char, false>;
 using _Tx6 = moneypunct<char, true>;
-using _Tx7 = time_get<char, _Initer>;
-using _Tx8 = time_put<char, _Outiter>;
+using _Tx7 = time_get<char>;
+using _Tx8 = time_put<char>;
 
 void __CLRCALL_OR_CDECL locale::_Locimp::_Makexloc(const _Locinfo& lobj, locale::category cat, _Locimp* ptrimp,
     const locale* ptrloc) { // setup exotic char part of a new locale
diff --git a/stl/src/xmath.hpp b/stl/src/xmath.hpp
index 0ae87457a0b..32bd8b60f7b 100644
--- a/stl/src/xmath.hpp
+++ b/stl/src/xmath.hpp
@@ -15,25 +15,25 @@
 #define _D3 0
 
 // IEEE 754 double properties
-#define HUGE_EXP (int) (_DMAX * 900L / 1000)
+#define HUGE_EXP static_cast<int>(_DMAX * 900L / 1000)
 
 // IEEE 754 float properties
-#define FHUGE_EXP (int) (_FMAX * 900L / 1000)
+#define FHUGE_EXP static_cast<int>(_FMAX * 900L / 1000)
 
 #define _F0 1 // little-endian
 #define _F1 0
 
 // IEEE 754 long double properties
-#define LHUGE_EXP (int) (_LMAX * 900L / 1000)
+#define LHUGE_EXP static_cast<int>(_LMAX * 900L / 1000)
 
 #define _L0 3 // little-endian, 64-bit long doubles
 #define _L1 2
 #define _L2 1
 #define _L3 0
 
-#define DSIGN(x) (((_Dval*) (char*) &(x))->_Sh[_D0] & _DSIGN)
-#define FSIGN(x) (((_Fval*) (char*) &(x))->_Sh[_F0] & _FSIGN)
-#define LSIGN(x) (((_Lval*) (char*) &(x))->_Sh[_L0] & _LSIGN)
+#define DSIGN(x) (reinterpret_cast<_Dval*>(&(x))->_Sh[_D0] & _DSIGN)
+#define FSIGN(x) (reinterpret_cast<_Fval*>(&(x))->_Sh[_F0] & _FSIGN)
+#define LSIGN(x) (reinterpret_cast<_Lval*>(&(x))->_Sh[_L0] & _LSIGN)
 
 #define _Fg _F1 // least-significant 16-bit word
 #define _Dg _D3
diff --git a/stl/src/xnotify.cpp b/stl/src/xnotify.cpp
index c3e87255399..bf362c717ea 100644
--- a/stl/src/xnotify.cpp
+++ b/stl/src/xnotify.cpp
@@ -39,16 +39,16 @@ void _Cnd_register_at_thread_exit(
     _At_thread_exit_block* block = &_Thread_exit_data;
 
     _Lock_at_thread_exit_mutex();
-    while (block != 0) { // loop through list of blocks
+    while (block != nullptr) { // loop through list of blocks
         if (block->num_used == _Nitems) { // block is full; move to next block and allocate
-            if (block->next == 0) {
-                block->next = (_At_thread_exit_block*) calloc(1, sizeof(_At_thread_exit_block));
+            if (block->next == nullptr) {
+                block->next = static_cast<_At_thread_exit_block*>(calloc(1, sizeof(_At_thread_exit_block)));
             }
 
             block = block->next;
         } else { // found block with available space
             for (int i = 0; i < _Nitems; ++i) { // find empty slot
-                if (block->data[i].mtx == 0) { // store into empty slot
+                if (block->data[i].mtx == nullptr) { // store into empty slot
                     block->data[i].id._Id = GetCurrentThreadId();
                     block->data[i].mtx    = mtx;
                     block->data[i].cnd    = cnd;
@@ -57,7 +57,7 @@ void _Cnd_register_at_thread_exit(
                     break;
                 }
             }
-            block = 0;
+            block = nullptr;
         }
     }
     _Unlock_at_thread_exit_mutex();
@@ -68,10 +68,10 @@ void _Cnd_unregister_at_thread_exit(_Mtx_t mtx) { // unregister condition variab
     _At_thread_exit_block* block = &_Thread_exit_data;
 
     _Lock_at_thread_exit_mutex();
-    while (block != 0) { // loop through list of blocks
+    while (block != nullptr) { // loop through list of blocks
         for (int i = 0; block->num_used != 0 && i < _Nitems; ++i) {
             if (block->data[i].mtx == mtx) { // release slot
-                block->data[i].mtx = 0;
+                block->data[i].mtx = nullptr;
                 --block->num_used;
             }
         }
@@ -87,15 +87,15 @@ void _Cnd_do_broadcast_at_thread_exit() { // notify condition variables waiting
     const unsigned int currentThreadId = _Thrd_id();
 
     _Lock_at_thread_exit_mutex();
-    while (block != 0) { // loop through list of blocks
+    while (block != nullptr) { // loop through list of blocks
         for (int i = 0; block->num_used != 0 && i < _Nitems; ++i) {
-            if (block->data[i].mtx != 0 && block->data[i].id._Id == currentThreadId) { // notify and release slot
+            if (block->data[i].mtx != nullptr && block->data[i].id._Id == currentThreadId) { // notify and release slot
                 if (block->data[i].res) {
                     *block->data[i].res = 1;
                 }
                 _Mtx_unlock(block->data[i].mtx);
                 _Cnd_broadcast(block->data[i].cnd);
-                block->data[i].mtx = 0;
+                block->data[i].mtx = nullptr;
                 --block->num_used;
             }
         }
diff --git a/stl/src/xonce.cpp b/stl/src/xonce.cpp
index ecec8cf53b3..5c6a5f9c2f9 100644
--- a/stl/src/xonce.cpp
+++ b/stl/src/xonce.cpp
@@ -14,7 +14,7 @@ _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Execute_once(
     static_assert(sizeof(_Flag._Opaque) == sizeof(INIT_ONCE), "invalid size");
 
     return __crtInitOnceExecuteOnce(
-        reinterpret_cast<PINIT_ONCE>(&_Flag._Opaque), reinterpret_cast<PINIT_ONCE_FN>(_Callback), _Pv, 0);
+        reinterpret_cast<PINIT_ONCE>(&_Flag._Opaque), reinterpret_cast<PINIT_ONCE_FN>(_Callback), _Pv, nullptr);
 }
 
 [[noreturn]] _CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL
diff --git a/stl/src/xstod.cpp b/stl/src/xstod.cpp
index 32237e76fb8..821cd15fb8a 100644
--- a/stl/src/xstod.cpp
+++ b/stl/src/xstod.cpp
@@ -18,7 +18,7 @@ _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL _Stodx(const CTYPE* s, CTYPE** endpt
 
     _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL
     _Stod(const CTYPE* s, CTYPE** endptr, long pten) { // convert string, discard error code
-    return _Stodx(s, endptr, pten, 0);
+    return _Stodx(s, endptr, pten, nullptr);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xstof.cpp b/stl/src/xstof.cpp
index 0c1b790cc76..0c98e1a855f 100644
--- a/stl/src/xstof.cpp
+++ b/stl/src/xstof.cpp
@@ -18,7 +18,7 @@ _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL _Stofx(const CTYPE* s, CTYPE** endpt
 
     _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL
     _Stof(const CTYPE* s, CTYPE** endptr, long pten) { // convert string, discard error code
-    return _Stofx(s, endptr, pten, 0);
+    return _Stofx(s, endptr, pten, nullptr);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xstoflt.cpp b/stl/src/xstoflt.cpp
index 3bdc27591c8..98c203cdd7a 100644
--- a/stl/src/xstoflt.cpp
+++ b/stl/src/xstoflt.cpp
@@ -36,9 +36,9 @@ int _Stoflt(const char* s0, const char* s, char** endptr, long lo[],
         ++s;
     }
 
-    while (isdigit((unsigned char) *s)) {
+    while (isdigit(static_cast<unsigned char>(*s))) {
         if (nsig < maxsig) {
-            buf[nsig++] = (char) (*s - '0'); // accumulate a digit
+            buf[nsig++] = static_cast<char>(*s - '0'); // accumulate a digit
         } else { // just scale exponent and note nonzero digits
             ++lo[0];
             if (*s != '0') {
@@ -60,9 +60,9 @@ int _Stoflt(const char* s0, const char* s, char** endptr, long lo[],
         }
     }
 
-    for (; isdigit((unsigned char) *s); ++s, seen = 1) {
+    for (; isdigit(static_cast<unsigned char>(*s)); ++s, seen = 1) {
         if (nsig < maxsig) { // accumulate a fraction digit
-            buf[nsig++] = (char) (*s - '0');
+            buf[nsig++] = static_cast<char>(*s - '0');
             --lo[0];
         } else if (*s != '0') {
             sticky = 1;
@@ -100,9 +100,9 @@ int _Stoflt(const char* s0, const char* s, char** endptr, long lo[],
             int eseen        = 0;
             long lexp        = 0;
 
-            for (; isdigit((unsigned char) *s); ++s, eseen = 1) {
+            for (; isdigit(static_cast<unsigned char>(*s)); ++s, eseen = 1) {
                 if (lexp < 100000000) { // else overflow
-                    lexp = lexp * 10 + (unsigned char) *s - '0';
+                    lexp = lexp * 10 + static_cast<unsigned char>(*s) - '0';
                 }
             }
 
@@ -122,7 +122,7 @@ int _Stoflt(const char* s0, const char* s, char** endptr, long lo[],
     }
 
     if (endptr) {
-        *endptr = (char*) (seen ? s : s0); // roll back if bad parse
+        *endptr = const_cast<char*>(seen ? s : s0); // roll back if bad parse
     }
 
     return word;
diff --git a/stl/src/xstol.cpp b/stl/src/xstol.cpp
index 700fa84c5b6..35a9e052fee 100644
--- a/stl/src/xstol.cpp
+++ b/stl/src/xstol.cpp
@@ -23,32 +23,32 @@ _CRTIMP2_PURE long __CLRCALL_PURE_OR_CDECL _Stolx(
     char sign;
     unsigned long x;
 
-    if (endptr == 0) {
+    if (endptr == nullptr) {
         endptr = &se;
     }
 
     sc = s;
-    while (isspace((unsigned char) *sc)) {
+    while (isspace(static_cast<unsigned char>(*sc))) {
         ++sc;
     }
 
     sign = *sc == '-' || *sc == '+' ? *sc++ : '+';
     x    = _Stoulx(sc, endptr, base, perr);
     if (sc == *endptr) {
-        *endptr = (char*) s;
+        *endptr = const_cast<char*>(s);
     }
 
     if (s == *endptr && x != 0 || sign == '+' && LONG_MAX < x
-        || sign == '-' && 0 - (unsigned long) LONG_MIN < x) { // overflow
+        || sign == '-' && 0 - static_cast<unsigned long>(LONG_MIN) < x) { // overflow
         errno = ERANGE;
-        if (perr != 0) {
+        if (perr != nullptr) {
             *perr = 1;
         }
 
         return sign == '-' ? LONG_MIN : LONG_MAX;
     }
 
-    return (long) (sign == '-' ? 0 - x : x);
+    return static_cast<long>(sign == '-' ? 0 - x : x);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xstold.cpp b/stl/src/xstold.cpp
index 55057b9f464..f8a66cb8827 100644
--- a/stl/src/xstold.cpp
+++ b/stl/src/xstold.cpp
@@ -18,7 +18,7 @@ _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL _Stoldx(const CTYPE* s, CTYPE** endp
 
     _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL
     _Stold(const CTYPE* s, CTYPE** endptr, long pten) { // convert string, discard error code
-    return _Stoldx(s, endptr, pten, 0);
+    return _Stoldx(s, endptr, pten, nullptr);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xstoll.cpp b/stl/src/xstoll.cpp
index fda3e0e9b3f..af01eeb597c 100644
--- a/stl/src/xstoll.cpp
+++ b/stl/src/xstoll.cpp
@@ -21,37 +21,37 @@ _CRTIMP2_PURE long long __CLRCALL_PURE_OR_CDECL _Stollx(
     char sign;
     unsigned long long x;
 
-    if (endptr == 0) {
+    if (endptr == nullptr) {
         endptr = &se;
     }
 
     sc = s;
-    while (isspace((unsigned char) *sc)) {
+    while (isspace(static_cast<unsigned char>(*sc))) {
         ++sc;
     }
 
-    sign = (char) (*sc == '-' || *sc == '+' ? *sc++ : '+');
+    sign = static_cast<char>(*sc == '-' || *sc == '+' ? *sc++ : '+');
     x    = _Stoullx(sc, endptr, base, perr);
     if (sc == *endptr) {
-        *endptr = (char*) s;
+        *endptr = const_cast<char*>(s);
     }
 
     if (s == *endptr && x != 0 || sign == '+' && LLONG_MAX < x
-        || sign == '-' && 0 - (unsigned long long) LLONG_MIN < x) { // overflow
+        || sign == '-' && 0 - static_cast<unsigned long long>(LLONG_MIN) < x) { // overflow
         errno = ERANGE;
-        if (perr != 0) {
+        if (perr != nullptr) {
             *perr = 1;
         }
 
         return sign == '-' ? LLONG_MIN : LLONG_MAX;
     }
 
-    return (long long) (sign == '-' ? 0 - x : x);
+    return static_cast<long long>(sign == '-' ? 0 - x : x);
 }
 
 _CRTIMP2_PURE long long(__CLRCALL_PURE_OR_CDECL _Stoll)(
     const char* s, char** endptr, int base) { // convert string, discard error code
-    return _Stollx(s, endptr, base, 0);
+    return _Stollx(s, endptr, base, nullptr);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xstopfx.cpp b/stl/src/xstopfx.cpp
index a33b5054d28..b9d44fe14b6 100644
--- a/stl/src/xstopfx.cpp
+++ b/stl/src/xstopfx.cpp
@@ -13,7 +13,7 @@ int _Stopfx(const char** ps, char** endptr) { // parse prefix of floating-point
     const char* s = *ps;
     int code      = 0;
 
-    while (isspace((unsigned char) *s)) {
+    while (isspace(static_cast<unsigned char>(*s))) {
         ++s;
     }
 
@@ -35,15 +35,15 @@ int _Stopfx(const char** ps, char** endptr) { // parse prefix of floating-point
             if (*q == '(') { // got '(', skip through ')'
                 do {
                     ++q;
-                } while (isalnum((unsigned char) *q) || *q == '_');
+                } while (isalnum(static_cast<unsigned char>(*q)) || *q == '_');
 
                 if (*q == ')') {
                     s = ++q;
                 }
             }
         }
-        if (endptr != 0) {
-            *endptr = (char*) s;
+        if (endptr != nullptr) {
+            *endptr = const_cast<char*>(s);
         }
     } else if (*s == 'i' || *s == 'I') { // parse "inf" or fail
         if ((*++s != 'n' && *s != 'N') || (*++s != 'f' && *s != 'F')) { // parse failed, roll back pointer
@@ -62,8 +62,8 @@ int _Stopfx(const char** ps, char** endptr) { // parse prefix of floating-point
             }
         }
 
-        if (endptr != 0) {
-            *endptr = (char*) s;
+        if (endptr != nullptr) {
+            *endptr = const_cast<char*>(s);
         }
     } else if (*s == '0' && (s[1] == 'x' || s[1] == 'X')) { // test for valid hex field following 0x or 0X
         const char* s1 = s + 2;
@@ -71,7 +71,7 @@ int _Stopfx(const char** ps, char** endptr) { // parse prefix of floating-point
             ++s1;
         }
 
-        if (isxdigit((unsigned char) *s1)) {
+        if (isxdigit(static_cast<unsigned char>(*s1))) {
             s += 2;
             code |= FL_HEX;
         } else {
diff --git a/stl/src/xstoul.cpp b/stl/src/xstoul.cpp
index c6f56229410..7e36fa0bf4b 100644
--- a/stl/src/xstoul.cpp
+++ b/stl/src/xstoul.cpp
@@ -21,15 +21,9 @@ constexpr int _Base_max = 36; // largest valid base
 static const char digits[] = // valid digits
     "0123456789abcdefghijklmnopqrstuvwxyz";
 
-#if (ULONG_MAX >> 16) >> 16 == 0xffffffff
-// 64-bits!
-static const char ndigs[_Base_max + 1] = {0, 0, 65, 41, 33, 28, 25, 23, 22, 21, 20, 19, 18, 18, 17, 17, 17, 16, 16, 16,
-    15, 15, 15, 15, 14, 14, 14, 14, 14, 14, 14, 13, 13, 13, 13, 13, 13};
-#else // (ULONG_MAX >> 16) >> 16 == 0xffffffff
 // 32-bits!
 static const char ndigs[_Base_max + 1] = {0, 0, 33, 21, 17, 14, 13, 12, 11, 11, 10, 10, 9, 9, 9, 9, 9, 8, 8, 8, 8, 8, 8,
     8, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7};
-#endif // (ULONG_MAX >> 16) >> 16 == 0xffffffff
 
 _CRTIMP2_PURE unsigned long __CLRCALL_PURE_OR_CDECL _Stoulx(
     const char* s, char** endptr, int base, int* perr) { // convert string to unsigned long, with checking
@@ -43,19 +37,19 @@ _CRTIMP2_PURE unsigned long __CLRCALL_PURE_OR_CDECL _Stoulx(
     unsigned long x;
     unsigned long y;
 
-    if (perr != 0) {
+    if (perr != nullptr) {
         *perr = 0;
     }
 
     sc = s;
-    while (isspace((unsigned char) *sc)) {
+    while (isspace(static_cast<unsigned char>(*sc))) {
         ++sc;
     }
 
     sign = *sc == '-' || *sc == '+' ? *sc++ : '+';
     if (base < 0 || base == 1 || _Base_max < base) { // silly base
-        if (endptr != 0) {
-            *endptr = (char*) s;
+        if (endptr != nullptr) {
+            *endptr = const_cast<char*>(s);
         }
 
         return 0;
@@ -80,15 +74,16 @@ _CRTIMP2_PURE unsigned long __CLRCALL_PURE_OR_CDECL _Stoulx(
     }
 
     x = 0;
-    for (s2 = sc, y = 0; (sd = (char*) memchr(&digits[0], tolower(*sc), base)) != 0; ++sc) { // accumulate digits
+    for (s2 = sc, y = 0; (sd = static_cast<const char*>(memchr(&digits[0], tolower(*sc), base))) != 0;
+         ++sc) { // accumulate digits
         y   = x;
-        dig = (char) (sd - digits); // for overflow checking
+        dig = static_cast<char>(sd - digits); // for overflow checking
         x   = x * base + dig;
     }
 
     if (s1 == sc) { // check string validity
-        if (endptr != 0) {
-            *endptr = (char*) s;
+        if (endptr != nullptr) {
+            *endptr = const_cast<char*>(s);
         }
 
         return 0;
@@ -97,7 +92,7 @@ _CRTIMP2_PURE unsigned long __CLRCALL_PURE_OR_CDECL _Stoulx(
     n = sc - s2 - ndigs[base];
     if (n >= 0 && (0 < n || x < x - dig || (x - dig) / base != y)) { // overflow
         errno = ERANGE;
-        if (perr != 0) {
+        if (perr != nullptr) {
             *perr = 1;
         }
 
@@ -109,8 +104,8 @@ _CRTIMP2_PURE unsigned long __CLRCALL_PURE_OR_CDECL _Stoulx(
         x = 0 - x;
     }
 
-    if (endptr != 0) {
-        *endptr = (char*) sc;
+    if (endptr != nullptr) {
+        *endptr = const_cast<char*>(sc);
     }
 
     return x;
@@ -118,7 +113,7 @@ _CRTIMP2_PURE unsigned long __CLRCALL_PURE_OR_CDECL _Stoulx(
 
 _CRTIMP2_PURE unsigned long __CLRCALL_PURE_OR_CDECL _Stoul(
     const char* s, char** endptr, int base) { // convert string, discard error code
-    return _Stoulx(s, endptr, base, 0);
+    return _Stoulx(s, endptr, base, nullptr);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xstoull.cpp b/stl/src/xstoull.cpp
index b33d0797eb6..5875fb47809 100644
--- a/stl/src/xstoull.cpp
+++ b/stl/src/xstoull.cpp
@@ -35,19 +35,19 @@ _CRTIMP2_PURE unsigned long long __CLRCALL_PURE_OR_CDECL _Stoullx(
     unsigned long long x;
     unsigned long long y;
 
-    if (perr != 0) {
+    if (perr != nullptr) {
         *perr = 0;
     }
 
     sc = s;
-    while (isspace((unsigned char) *sc)) {
+    while (isspace(static_cast<unsigned char>(*sc))) {
         ++sc;
     }
 
-    sign = (char) (*sc == '-' || *sc == '+' ? *sc++ : '+');
+    sign = static_cast<char>(*sc == '-' || *sc == '+' ? *sc++ : '+');
     if (base < 0 || base == 1 || _Base_max < base) { // silly base
-        if (endptr != 0) {
-            *endptr = (char*) s;
+        if (endptr != nullptr) {
+            *endptr = const_cast<char*>(s);
         }
 
         return 0;
@@ -70,16 +70,16 @@ _CRTIMP2_PURE unsigned long long __CLRCALL_PURE_OR_CDECL _Stoullx(
     }
 
     x = 0;
-    for (s2 = sc, y = 0, dig = 0; (sd = (char*) memchr(&digits[0], tolower(*sc), base)) != 0;
+    for (s2 = sc, y = 0, dig = 0; (sd = static_cast<const char*>(memchr(&digits[0], tolower(*sc), base))) != 0;
          ++sc) { // accumulate digits
         y   = x;
-        dig = (char) (sd - digits); // for overflow checking
+        dig = static_cast<char>(sd - digits); // for overflow checking
         x   = x * base + dig;
     }
 
     if (s1 == sc) { // check string validity
-        if (endptr != 0) {
-            *endptr = (char*) s;
+        if (endptr != nullptr) {
+            *endptr = const_cast<char*>(s);
         }
 
         return 0;
@@ -88,7 +88,7 @@ _CRTIMP2_PURE unsigned long long __CLRCALL_PURE_OR_CDECL _Stoullx(
     n = sc - s2 - ndigs[base];
     if (n >= 0 && (0 < n || x < x - dig || (x - dig) / base != y)) { // overflow
         errno = ERANGE;
-        if (perr != 0) {
+        if (perr != nullptr) {
             *perr = 1;
         }
 
@@ -100,8 +100,8 @@ _CRTIMP2_PURE unsigned long long __CLRCALL_PURE_OR_CDECL _Stoullx(
         x = 0 - x;
     }
 
-    if (endptr != 0) {
-        *endptr = (char*) sc;
+    if (endptr != nullptr) {
+        *endptr = const_cast<char*>(sc);
     }
 
     return x;
@@ -109,7 +109,7 @@ _CRTIMP2_PURE unsigned long long __CLRCALL_PURE_OR_CDECL _Stoullx(
 
 _CRTIMP2_PURE unsigned long long __CLRCALL_PURE_OR_CDECL _Stoull(
     const char* s, char** endptr, int base) { // convert string, discard error code
-    return _Stoullx(s, endptr, base, 0);
+    return _Stoullx(s, endptr, base, nullptr);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xstoxflt.cpp b/stl/src/xstoxflt.cpp
index c60fb72d265..7ef6b4d2018 100644
--- a/stl/src/xstoxflt.cpp
+++ b/stl/src/xstoxflt.cpp
@@ -41,7 +41,7 @@ int _Stoxflt(const char* s0, const char* s, char** endptr, long lo[],
         seen = 1;
     }
 
-    while ((pd = (char*) memchr(&digits[0], *s, 22)) != 0) {
+    while ((pd = static_cast<const char*>(memchr(&digits[0], *s, 22))) != 0) {
         if (nsig <= maxsig) {
             buf[nsig++] = vals[pd - digits]; // accumulate a digit
         } else {
@@ -62,7 +62,7 @@ int _Stoxflt(const char* s0, const char* s, char** endptr, long lo[],
         }
     }
 
-    for (; (pd = (char*) memchr(&digits[0], *s, 22)) != 0; ++s, seen = 1) {
+    for (; (pd = static_cast<const char*>(memchr(&digits[0], *s, 22))) != 0; ++s, seen = 1) {
         if (nsig <= maxsig) { // accumulate a fraction digit
             buf[nsig++] = vals[pd - digits];
             --lo[0];
@@ -106,9 +106,9 @@ int _Stoxflt(const char* s0, const char* s, char** endptr, long lo[],
             int eseen        = 0;
             long lexp        = 0;
 
-            for (; isdigit((unsigned char) *s); ++s, eseen = 1) {
+            for (; isdigit(static_cast<unsigned char>(*s)); ++s, eseen = 1) {
                 if (lexp < 100000000) { // else overflow
-                    lexp = lexp * 10 + (unsigned char) *s - '0';
+                    lexp = lexp * 10 + static_cast<unsigned char>(*s) - '0';
                 }
             }
 
@@ -128,7 +128,7 @@ int _Stoxflt(const char* s0, const char* s, char** endptr, long lo[],
     }
 
     if (endptr) {
-        *endptr = (char*) (seen ? s : s0); // roll back if bad parse
+        *endptr = const_cast<char*>(seen ? s : s0); // roll back if bad parse
     }
 
     return word;
diff --git a/stl/src/xtime.cpp b/stl/src/xtime.cpp
index 5f1c7f1526f..0de318718d8 100644
--- a/stl/src/xtime.cpp
+++ b/stl/src/xtime.cpp
@@ -73,7 +73,7 @@ long _Xtime_diff_to_millis(const xtime* xt) { // convert time to milliseconds
 }
 
 int xtime_get(xtime* xt, int type) { // get current time
-    if (type != TIME_UTC || xt == 0) {
+    if (type != TIME_UTC || xt == nullptr) {
         type = 0;
     } else {
         sys_get_time(xt);
diff --git a/stl/src/xtowlower.cpp b/stl/src/xtowlower.cpp
index 8467d22ccb6..630f148bc69 100644
--- a/stl/src/xtowlower.cpp
+++ b/stl/src/xtowlower.cpp
@@ -16,7 +16,7 @@ _CRTIMP2_PURE wchar_t __CLRCALL_PURE_OR_CDECL _Towlower(
     if (_Ch != WEOF) {
         if (_Ctype->_LocaleName == nullptr && _Ch < 256) { // handle ASCII character in C locale
             if (L'A' <= _Ch && _Ch <= L'Z') {
-                _Res = (wchar_t)(_Ch - L'A' + L'a');
+                _Res = static_cast<wchar_t>(_Ch - L'A' + L'a');
             }
         } else if (__crtLCMapStringW(_Ctype->_LocaleName, LCMAP_LOWERCASE, &_Ch, 1, &_Res, 1) == 0) {
             _Res = _Ch;
@@ -28,7 +28,7 @@ _CRTIMP2_PURE wchar_t __CLRCALL_PURE_OR_CDECL _Towlower(
 
 #ifdef MRTDLL
 _CRTIMP2_PURE unsigned short __CLRCALL_PURE_OR_CDECL _Towlower(unsigned short _Ch, const _Ctypevec* _Ctype) {
-    return _Towlower((wchar_t) _Ch, _Ctype);
+    return _Towlower(static_cast<wchar_t>(_Ch), _Ctype);
 }
 #endif
 
diff --git a/stl/src/xtowupper.cpp b/stl/src/xtowupper.cpp
index ed9c28ef5ca..84901eae6ef 100644
--- a/stl/src/xtowupper.cpp
+++ b/stl/src/xtowupper.cpp
@@ -16,7 +16,7 @@ _CRTIMP2_PURE wchar_t __CLRCALL_PURE_OR_CDECL _Towupper(
     if (_Ch != WEOF) {
         if (_Ctype->_LocaleName == nullptr && _Ch < 256) { // handle ASCII character in C locale
             if (L'a' <= _Ch && _Ch <= L'z') {
-                _Res = (wchar_t)(_Ch - L'a' + L'A');
+                _Res = static_cast<wchar_t>(_Ch - L'a' + L'A');
             }
         } else if (__crtLCMapStringW(_Ctype->_LocaleName, LCMAP_UPPERCASE, &_Ch, 1, &_Res, 1) == 0) {
             _Res = _Ch;
@@ -28,7 +28,7 @@ _CRTIMP2_PURE wchar_t __CLRCALL_PURE_OR_CDECL _Towupper(
 
 #ifdef MRTDLL
 _CRTIMP2_PURE unsigned short __CLRCALL_PURE_OR_CDECL _Towupper(unsigned short _Ch, const _Ctypevec* _Ctype) {
-    return _Towupper((wchar_t) _Ch, _Ctype);
+    return _Towupper(static_cast<wchar_t>(_Ch), _Ctype);
 }
 #endif
 
diff --git a/stl/src/xwctomb.cpp b/stl/src/xwctomb.cpp
index 6f696b7edd1..2c94e37da6a 100644
--- a/stl/src/xwctomb.cpp
+++ b/stl/src/xwctomb.cpp
@@ -49,10 +49,9 @@ _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Wcrtomb(char* s, wchar_t wchar, mbsta
             return -1;
         }
 
-        *s = (char) wchar;
+        *s = static_cast<char>(wchar);
         return sizeof(char);
     } else {
-        int size;
         BOOL defused = 0;
         _Cvtvec cvtvec;
 
@@ -61,8 +60,8 @@ _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Wcrtomb(char* s, wchar_t wchar, mbsta
             ploc   = &cvtvec;
         }
 
-        if (((size = WideCharToMultiByte(ploc->_Page, 0, &wchar, 1, s, ploc->_Mbcurmax, nullptr, &defused)) == 0)
-            || (defused)) {
+        const int size = WideCharToMultiByte(ploc->_Page, 0, &wchar, 1, s, ploc->_Mbcurmax, nullptr, &defused);
+        if (size == 0 || defused) {
             errno = EILSEQ;
             return -1;
         }
@@ -73,7 +72,7 @@ _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Wcrtomb(char* s, wchar_t wchar, mbsta
 
 #ifdef MRTDLL
 _CRTIMP2_PURE int __CLRCALL_PURE_OR_CDECL _Wcrtomb(char* s, unsigned short wchar, mbstate_t* pst, const _Cvtvec* ploc) {
-    return _Wcrtomb(s, (wchar_t) wchar, pst, ploc);
+    return _Wcrtomb(s, static_cast<wchar_t>(wchar), pst, ploc);
 }
 #endif // MRTDLL
 
diff --git a/stl/src/xwstod.cpp b/stl/src/xwstod.cpp
index 7332252de8f..499d19e2852 100644
--- a/stl/src/xwstod.cpp
+++ b/stl/src/xwstod.cpp
@@ -17,7 +17,7 @@ _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL _WStodx(const CTYPE* s, CTYPE** endp
 
     _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL
     _WStod(const CTYPE* s, CTYPE** endptr, long pten) { // convert string, discard error code
-    return _WStodx(s, endptr, pten, 0);
+    return _WStodx(s, endptr, pten, nullptr);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xwstof.cpp b/stl/src/xwstof.cpp
index aaaf3c28c46..cbe81b4f3f0 100644
--- a/stl/src/xwstof.cpp
+++ b/stl/src/xwstof.cpp
@@ -16,7 +16,7 @@ _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL _WStofx(const CTYPE* s, CTYPE** endp
 
     _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL
     _WStof(const CTYPE* s, CTYPE** endptr, long pten) { // convert string, discard error code
-    return _WStofx(s, endptr, pten, 0);
+    return _WStofx(s, endptr, pten, nullptr);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xwstoflt.cpp b/stl/src/xwstoflt.cpp
index a24c70b6bfd..7f5f3fddac4 100644
--- a/stl/src/xwstoflt.cpp
+++ b/stl/src/xwstoflt.cpp
@@ -37,7 +37,7 @@ int _WStoflt(const wchar_t* s0, const wchar_t* s, wchar_t** endptr, long lo[],
 
     while (iswdigit(*s)) {
         if (nsig <= maxsig) {
-            buf[nsig++] = (char) (*s - L'0'); // accumulate a digit
+            buf[nsig++] = static_cast<char>(*s - L'0'); // accumulate a digit
         } else {
             ++lo[0]; // too many digits, just scale exponent
         }
@@ -60,7 +60,7 @@ int _WStoflt(const wchar_t* s0, const wchar_t* s, wchar_t** endptr, long lo[],
 
     while (iswdigit(*s)) {
         if (nsig <= maxsig) { // accumulate a fraction digit
-            buf[nsig++] = (char) (*s - L'0');
+            buf[nsig++] = static_cast<char>(*s - L'0');
             --lo[0];
         }
 
@@ -126,7 +126,7 @@ int _WStoflt(const wchar_t* s0, const wchar_t* s, wchar_t** endptr, long lo[],
     }
 
     if (endptr) {
-        *endptr = (wchar_t*) (seen ? s : s0); // roll back if bad parse
+        *endptr = const_cast<wchar_t*>(seen ? s : s0); // roll back if bad parse
     }
 
     return word;
diff --git a/stl/src/xwstold.cpp b/stl/src/xwstold.cpp
index d8dcc0cdb51..e00bb8194aa 100644
--- a/stl/src/xwstold.cpp
+++ b/stl/src/xwstold.cpp
@@ -16,7 +16,7 @@ _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL _WStoldx(const CTYPE* s, CTYPE** end
 
     _CRTIMP2_PURE FTYPE __CLRCALL_PURE_OR_CDECL
     _WStold(const CTYPE* s, CTYPE** endptr, long pten) { // convert string, discard error code
-    return _WStoldx(s, endptr, pten, 0);
+    return _WStoldx(s, endptr, pten, nullptr);
 }
 
 _END_EXTERN_C_UNLESS_PURE
diff --git a/stl/src/xwstopfx.cpp b/stl/src/xwstopfx.cpp
index 788efb4f0e5..b3d74711b4d 100644
--- a/stl/src/xwstopfx.cpp
+++ b/stl/src/xwstopfx.cpp
@@ -41,8 +41,8 @@ int _WStopfx(const wchar_t** ps, wchar_t** endptr) { // parse prefix of floating
             }
         }
 
-        if (endptr != 0) {
-            *endptr = (wchar_t*) s;
+        if (endptr != nullptr) {
+            *endptr = const_cast<wchar_t*>(s);
         }
     } else if (*s == L'i' || *s == L'I') { // parse "inf" or fail
         if ((*++s != L'n' && *s != L'N') || (*++s != L'f' && *s != L'F')) { // parse failed, roll back pointer
@@ -60,8 +60,8 @@ int _WStopfx(const wchar_t** ps, wchar_t** endptr) { // parse prefix of floating
             }
         }
 
-        if (endptr != 0) {
-            *endptr = (wchar_t*) s;
+        if (endptr != nullptr) {
+            *endptr = const_cast<wchar_t*>(s);
         }
     } else if (*s == L'0' && (s[1] == L'x' || s[1] == L'X')) { // test for valid hex field following 0x or 0X
         const wchar_t* s1 = s + 2;
diff --git a/stl/src/xwstoxfl.cpp b/stl/src/xwstoxfl.cpp
index 2415692cb28..f694b9bd201 100644
--- a/stl/src/xwstoxfl.cpp
+++ b/stl/src/xwstoxfl.cpp
@@ -43,7 +43,7 @@ int _WStoxflt(const wchar_t* s0, const wchar_t* s, wchar_t** endptr, long lo[],
         seen = 1;
     }
 
-    while ((pd = (wchar_t*) wmemchr(&digits[0], *s, 22)) != 0) {
+    while ((pd = wmemchr(&digits[0], *s, 22)) != nullptr) {
         if (nsig <= maxsig) {
             buf[nsig++] = vals[pd - digits]; // accumulate a digit
         } else {
@@ -64,7 +64,7 @@ int _WStoxflt(const wchar_t* s0, const wchar_t* s, wchar_t** endptr, long lo[],
         }
     }
 
-    while ((pd = (wchar_t*) wmemchr(&digits[0], *s, 22)) != 0) {
+    while ((pd = wmemchr(&digits[0], *s, 22)) != nullptr) {
         if (nsig <= maxsig) { // accumulate a fraction digit
             buf[nsig++] = vals[pd - digits];
             --lo[0];
@@ -133,7 +133,7 @@ int _WStoxflt(const wchar_t* s0, const wchar_t* s, wchar_t** endptr, long lo[],
     }
 
     if (endptr) {
-        *endptr = (wchar_t*) (seen ? s : s0); // roll back if bad parse
+        *endptr = const_cast<wchar_t*>(seen ? s : s0); // roll back if bad parse
     }
 
     return word;
diff --git a/stl/src/xxstod.hpp b/stl/src/xxstod.hpp
index 8223e9a2808..25f93fb7f47 100644
--- a/stl/src/xxstod.hpp
+++ b/stl/src/xxstod.hpp
@@ -29,7 +29,7 @@
 
     extern FTYPE FNAME(Dtento)(FTYPE*, long, int*);
 
-    if (perr != 0) {
+    if (perr != nullptr) {
         *perr = 0;
     }
 
diff --git a/stl/src/xxxdtent.hpp b/stl/src/xxxdtent.hpp
index 31ba1e2711d..d4272282673 100644
--- a/stl/src/xxxdtent.hpp
+++ b/stl/src/xxxdtent.hpp
@@ -20,10 +20,10 @@ _EXTERN_C
 
 static const FTYPE tenth[] = {
     // 53-bit: 0.100000
-    (FTYPE)(FLIT(6710886.0) / FRAC_BITS),
-    (FTYPE)(FLIT(26843545.0) / FRAC_BITS_2),
-    (FTYPE)(FLIT(40265318.0) / FRAC_BITS_2 / FRAC_BITS),
-    (FTYPE)(FLIT(26843545.0) / FRAC_BITS_2 / FRAC_BITS_2),
+    static_cast<FTYPE>(FLIT(6710886.0) / FRAC_BITS),
+    static_cast<FTYPE>(FLIT(26843545.0) / FRAC_BITS_2),
+    static_cast<FTYPE>(FLIT(40265318.0) / FRAC_BITS_2 / FRAC_BITS),
+    static_cast<FTYPE>(FLIT(26843545.0) / FRAC_BITS_2 / FRAC_BITS_2),
 };
 
 #elif FBITS == 24
@@ -31,10 +31,10 @@ static const FTYPE tenth[] = {
 
 static const FTYPE tenth[] = {
     // 24-bit: 0.100000
-    (FTYPE)(FLIT(409.0) / FRAC_BITS),
-    (FTYPE)(FLIT(2457.0) / FRAC_BITS_2),
-    (FTYPE)(FLIT(2457.0) / FRAC_BITS_2 / FRAC_BITS),
-    (FTYPE)(FLIT(2457.0) / FRAC_BITS_2 / FRAC_BITS_2),
+    static_cast<FTYPE>(FLIT(409.0) / FRAC_BITS),
+    static_cast<FTYPE>(FLIT(2457.0) / FRAC_BITS_2),
+    static_cast<FTYPE>(FLIT(2457.0) / FRAC_BITS_2 / FRAC_BITS),
+    static_cast<FTYPE>(FLIT(2457.0) / FRAC_BITS_2 / FRAC_BITS_2),
 };
 
 #else // FBITS
@@ -81,7 +81,7 @@ FTYPE FNAME(Dtento)(FTYPE* xpx, long n, int* perr) { // compute *px * 10**n
     x = FNAME(Xp_getw)(xpx, ACSIZE);
     if (x == FLIT(0.0) || x == FCONST(Inf) || x == -FCONST(Inf)) { // report error and set errno
         errno = ERANGE;
-        if (perr != 0) {
+        if (perr != nullptr) {
             *perr |= 1;
         }
     }
diff --git a/stl/src/xxxprec.hpp b/stl/src/xxxprec.hpp
index c52edb96417..a5990e030d7 100644
--- a/stl/src/xxxprec.hpp
+++ b/stl/src/xxxprec.hpp
@@ -10,14 +10,6 @@
 _EXTERN_C
 #endif // defined(MRTDLL)
 
-#ifndef ldexpf
-#define ldexpf(x, y) ldexp((double) (x), (y))
-#endif // ldexp
-
-#ifndef sqrtf
-#define sqrtf(x) sqrt((double) (x))
-#endif // sqrtf
-
 #define BIG_EXP   (2 * FMAXEXP) // very large, as exponents go
 #define BITS_WORD (FBITS / 2) // all words same for now
 #define NBUF      4 // size of delay line for mulh
@@ -37,7 +29,7 @@ static void printit(const char* s, FTYPE* p, int n) { // print xp array
     int i;
     printf(s);
     for (i = 0; i < n && (p[i] != FLIT(0.0) || i == 0); ++i) {
-        printf(" %La", (long double) p[i]);
+        printf(" %La", static_cast<long double>(p[i]));
     }
     printf("\n");
 }
@@ -141,7 +133,7 @@ FTYPE* FNAME(Xp_addh)(FTYPE* p, int n, FTYPE x0) { // add a half-precision value
                     break;
                 }
 
-                if ((diff = (long) yexp - xexp) <= -mybits
+                if ((diff = static_cast<long>(yexp) - xexp) <= -mybits
                     && x0 != FLIT(0.0)) { // insert nonzero x0 and loop to renormalize
                     int j = k;
 
@@ -175,7 +167,7 @@ FTYPE* FNAME(Xp_addh)(FTYPE* p, int n, FTYPE x0) { // add a half-precision value
                     x0 = p[k];
                     FNAME(Dunscale)(&xexp, &x0);
                     if (prevexp - mybits < xexp) { // propagate bits up
-                        FNAME(Dint)(&x0, (short) (xexp - (prevexp - mybits)));
+                        FNAME(Dint)(&x0, static_cast<short>(xexp - (prevexp - mybits)));
                         FNAME(Dscale)(&x0, xexp);
                         if ((p[k] -= x0) == FLIT(0.0)) { // all bits carry, copy up words
                             COPY_UP(k, n)
@@ -274,12 +266,11 @@ FTYPE* FNAME(Xp_mulh)(FTYPE* p, int n, FTYPE x0) { // multiply by a half-precisi
 FTYPE* FNAME(Xp_setn)(FTYPE* p, int n, long x) { // load a long integer
 
 #if 27 <= FBITS
-    FNAME(Xp_setw)(p, n, (FTYPE) x);
-
+    FNAME(Xp_setw)(p, n, static_cast<FTYPE>(x));
 #else // 27 <= FBITS
-    FNAME(Xp_setw)(p, n, (FTYPE)(x / 10000));
-    FNAME(Xp_mulh)(p, n, (FTYPE) 10000);
-    FNAME(Xp_addh)(p, n, (FTYPE)(x % 10000));
+    FNAME(Xp_setw)(p, n, static_cast<FTYPE>(x / 10000));
+    FNAME(Xp_mulh)(p, n, static_cast<FTYPE>(10000));
+    FNAME(Xp_addh)(p, n, static_cast<FTYPE>(x % 10000));
 #endif // 27 <= FBITS
 
     return p;
diff --git a/tests/tr1/tests/regex3/test.cpp b/tests/tr1/tests/regex3/test.cpp
index e37aa5bdcad..634c944d313 100644
--- a/tests/tr1/tests/regex3/test.cpp
+++ b/tests/tr1/tests/regex3/test.cpp
@@ -316,8 +316,8 @@ static void test_uncoveredgrammar() {
     // test "."
     MyRgx rx1;
     MyRgx rx2;
-    STDString str1(T("Moon is white\n Sun is bright"));
-    STDString str2(T("Windows seven"));
+    STDString str1(T("Cats are cute\n Dogs are friendly"));
+    STDString str2(T("Prime number"));
     STDString str3(T("aaaqxzbbb"));
     STDString str4(T("aaa\nxzbbb"));
     static const STD regex_constants::syntax_option_type flag[6] = {