update libcxx to llvm9

upstream commit 1931d3cb20a00da732c5210b123656632982fde0

lib/libcxx/include/__bit_reference

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -69,7 +68,7 @@ public:
 
     _LIBCPP_INLINE_VISIBILITY void flip() _NOEXCEPT {*__seg_ ^= __mask_;}
     _LIBCPP_INLINE_VISIBILITY __bit_iterator<_Cp, false> operator&() const _NOEXCEPT
-        {return __bit_iterator<_Cp, false>(__seg_, static_cast<unsigned>(__ctz(__mask_)));}
+        {return __bit_iterator<_Cp, false>(__seg_, static_cast<unsigned>(__libcpp_ctz(__mask_)));}
 private:
     _LIBCPP_INLINE_VISIBILITY
     __bit_reference(__storage_pointer __s, __storage_type __m) _NOEXCEPT
@@ -141,7 +140,7 @@ public:
         {return static_cast<bool>(*__seg_ & __mask_);}
 
     _LIBCPP_INLINE_VISIBILITY __bit_iterator<_Cp, true> operator&() const _NOEXCEPT
-        {return __bit_iterator<_Cp, true>(__seg_, static_cast<unsigned>(__ctz(__mask_)));}
+        {return __bit_iterator<_Cp, true>(__seg_, static_cast<unsigned>(__libcpp_ctz(__mask_)));}
 private:
     _LIBCPP_INLINE_VISIBILITY
     _LIBCPP_CONSTEXPR
@@ -168,7 +167,7 @@ __find_bool_true(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type
         __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
         __storage_type __b = *__first.__seg_ & __m;
         if (__b)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__libcpp_ctz(__b)));
         if (__n == __dn)
             return __first + __n;
         __n -= __dn;
@@ -177,14 +176,14 @@ __find_bool_true(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type
     // do middle whole words
     for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
         if (*__first.__seg_)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(*__first.__seg_)));
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__libcpp_ctz(*__first.__seg_)));
     // do last partial word
     if (__n > 0)
     {
         __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
         __storage_type __b = *__first.__seg_ & __m;
         if (__b)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__libcpp_ctz(__b)));
     }
     return _It(__first.__seg_, static_cast<unsigned>(__n));
 }
@@ -204,7 +203,7 @@ __find_bool_false(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type
         __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
         __storage_type __b = ~*__first.__seg_ & __m;
         if (__b)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__libcpp_ctz(__b)));
         if (__n == __dn)
             return __first + __n;
         __n -= __dn;
@@ -215,7 +214,7 @@ __find_bool_false(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type
     {
         __storage_type __b = ~*__first.__seg_;
         if (__b)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__libcpp_ctz(__b)));
     }
     // do last partial word
     if (__n > 0)
@@ -223,7 +222,7 @@ __find_bool_false(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type
         __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
         __storage_type __b = ~*__first.__seg_ & __m;
         if (__b)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__libcpp_ctz(__b)));
     }
     return _It(__first.__seg_, static_cast<unsigned>(__n));
 }
@@ -255,18 +254,18 @@ __count_bool_true(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type
         __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
         __storage_type __dn = _VSTD::min(__clz_f, __n);
         __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-        __r = _VSTD::__popcount(*__first.__seg_ & __m);
+        __r = _VSTD::__libcpp_popcount(*__first.__seg_ & __m);
         __n -= __dn;
         ++__first.__seg_;
     }
     // do middle whole words
     for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
-        __r += _VSTD::__popcount(*__first.__seg_);
+        __r += _VSTD::__libcpp_popcount(*__first.__seg_);
     // do last partial word
     if (__n > 0)
     {
         __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        __r += _VSTD::__popcount(*__first.__seg_ & __m);
+        __r += _VSTD::__libcpp_popcount(*__first.__seg_ & __m);
     }
     return __r;
 }
@@ -286,18 +285,18 @@ __count_bool_false(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_typ
         __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
         __storage_type __dn = _VSTD::min(__clz_f, __n);
         __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-        __r = _VSTD::__popcount(~*__first.__seg_ & __m);
+        __r = _VSTD::__libcpp_popcount(~*__first.__seg_ & __m);
         __n -= __dn;
         ++__first.__seg_;
     }
     // do middle whole words
     for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
-        __r += _VSTD::__popcount(~*__first.__seg_);
+        __r += _VSTD::__libcpp_popcount(~*__first.__seg_);
     // do last partial word
     if (__n > 0)
     {
         __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        __r += _VSTD::__popcount(~*__first.__seg_ & __m);
+        __r += _VSTD::__libcpp_popcount(~*__first.__seg_ & __m);
     }
     return __r;
 }

lib/libcxx/include/__bsd_locale_defaults.h

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------- __bsd_locale_defaults.h -----------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // The BSDs have lots of *_l functions.  We don't want to define those symbols

lib/libcxx/include/__bsd_locale_fallbacks.h

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------- __bsd_locale_fallbacks.h ----------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // The BSDs have lots of *_l functions.  This file provides reimplementations

lib/libcxx/include/__config

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- __config ---------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -33,12 +32,16 @@
 #  define _GNUC_VER_NEW 0
 #endif
 
-#define _LIBCPP_VERSION 8000
+#define _LIBCPP_VERSION 9000
 
 #ifndef _LIBCPP_ABI_VERSION
 #  define _LIBCPP_ABI_VERSION 1
 #endif
 
+#ifndef __STDC_HOSTED__
+#  define _LIBCPP_FREESTANDING
+#endif
+
 #ifndef _LIBCPP_STD_VER
 #  if  __cplusplus <= 201103L
 #    define _LIBCPP_STD_VER 11
@@ -93,10 +96,12 @@
 // Enable optimized version of __do_get_(un)signed which avoids redundant copies.
 #  define _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
 // Use the smallest possible integer type to represent the index of the variant.
-// Previously libc++ used "unsigned int" exclusivly.
+// Previously libc++ used "unsigned int" exclusively.
 #  define _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION
 // Unstable attempt to provide a more optimized std::function
 #  define _LIBCPP_ABI_OPTIMIZED_FUNCTION
+// All the regex constants must be distinct and nonzero.
+#  define _LIBCPP_ABI_REGEX_CONSTANTS_NONZERO
 #elif _LIBCPP_ABI_VERSION == 1
 #  if !defined(_LIBCPP_OBJECT_FORMAT_COFF)
 // Enable compiling copies of now inline methods into the dylib to support
@@ -182,6 +187,10 @@
 #define _LIBCPP_CLANG_VER 0
 #endif
 
+#if defined(_LIBCPP_COMPILER_GCC) && __cplusplus < 201103L
+#error "libc++ does not support using GCC with C++03. Please enable C++11"
+#endif
+
 // FIXME: ABI detection should be done via compiler builtin macros. This
 // is just a placeholder until Clang implements such macros. For now assume
 // that Windows compilers pretending to be MSVC++ target the Microsoft ABI,
@@ -201,6 +210,10 @@
 #  endif
 #endif
 
+#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+# define _LIBCPP_ABI_VCRUNTIME
+#endif
+
 // Need to detect which libc we're using if we're on Linux.
 #if defined(__linux__)
 #  include <features.h>
@@ -257,7 +270,7 @@
 #  define _LIBCPP_WIN32API
 #  define _LIBCPP_LITTLE_ENDIAN
 #  define _LIBCPP_SHORT_WCHAR   1
-// Both MinGW and native MSVC provide a "MSVC"-like enviroment
+// Both MinGW and native MSVC provide a "MSVC"-like environment
 #  define _LIBCPP_MSVCRT_LIKE
 // If mingw not explicitly detected, assume using MS C runtime only if
 // a MS compatibility version is specified.
@@ -298,7 +311,7 @@
    // random data even when using sandboxing mechanisms such as chroots,
    // Capsicum, etc.
 #  define _LIBCPP_USING_ARC4_RANDOM
-#elif defined(__Fuchsia__)
+#elif defined(__Fuchsia__) || defined(__wasi__)
 #  define _LIBCPP_USING_GETENTROPY
 #elif defined(__native_client__)
    // NaCl's sandbox (which PNaCl also runs in) doesn't allow filesystem access,
@@ -332,7 +345,7 @@
 #  if defined(__FreeBSD__)
 #    define _LIBCPP_HAS_QUICK_EXIT
 #    define _LIBCPP_HAS_C11_FEATURES
-#  elif defined(__Fuchsia__)
+#  elif defined(__Fuchsia__) || defined(__wasi__)
 #    define _LIBCPP_HAS_QUICK_EXIT
 #    define _LIBCPP_HAS_TIMESPEC_GET
 #    define _LIBCPP_HAS_C11_FEATURES
@@ -400,10 +413,6 @@ typedef __char32_t char32_t;
 #define _LIBCPP_HAS_NO_STRONG_ENUMS
 #endif
 
-#if !(__has_feature(cxx_decltype))
-#define _LIBCPP_HAS_NO_DECLTYPE
-#endif
-
 #if __has_feature(cxx_attributes)
 #  define _LIBCPP_NORETURN [[noreturn]]
 #else
@@ -434,18 +443,6 @@ typedef __char32_t char32_t;
 #define _LIBCPP_HAS_NO_VARIADICS
 #endif
 
-#if !(__has_feature(cxx_generalized_initializers))
-#define _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
-#endif
-
-#if __has_feature(is_base_of)
-#define _LIBCPP_HAS_IS_BASE_OF
-#endif
-
-#if __has_feature(is_final)
-#define _LIBCPP_HAS_IS_FINAL
-#endif
-
 // Objective-C++ features (opt-in)
 #if __has_feature(objc_arc)
 #define _LIBCPP_HAS_OBJC_ARC
@@ -455,10 +452,6 @@ typedef __char32_t char32_t;
 #define _LIBCPP_HAS_OBJC_ARC_WEAK
 #endif
 
-#if !(__has_feature(cxx_constexpr))
-#define _LIBCPP_HAS_NO_CONSTEXPR
-#endif
-
 #if !(__has_feature(cxx_relaxed_constexpr))
 #define _LIBCPP_HAS_NO_CXX14_CONSTEXPR
 #endif
@@ -471,14 +464,6 @@ typedef __char32_t char32_t;
 #define _LIBCPP_HAS_NO_NOEXCEPT
 #endif
 
-#if __has_feature(underlying_type)
-#define _LIBCPP_UNDERLYING_TYPE(T) __underlying_type(T)
-#endif
-
-#if __has_feature(is_literal)
-#define _LIBCPP_IS_LITERAL(T) __is_literal(T)
-#endif
-
 #if !defined(_LIBCPP_HAS_NO_ASAN) && !__has_feature(address_sanitizer)
 #define _LIBCPP_HAS_NO_ASAN
 #endif
@@ -510,69 +495,20 @@ typedef __char32_t char32_t;
 
 #define _LIBCPP_NORETURN __attribute__((noreturn))
 
-#if _GNUC_VER >= 407
-#define _LIBCPP_UNDERLYING_TYPE(T) __underlying_type(T)
-#define _LIBCPP_IS_LITERAL(T) __is_literal_type(T)
-#define _LIBCPP_HAS_IS_FINAL
-#endif
-
-#if defined(__GNUC__) && _GNUC_VER >= 403
-#define _LIBCPP_HAS_IS_BASE_OF
-#endif
-
 #if !__EXCEPTIONS && !defined(_LIBCPP_NO_EXCEPTIONS)
 #define _LIBCPP_NO_EXCEPTIONS
 #endif
 
-// constexpr was added to GCC in 4.6.
-#if _GNUC_VER < 406
-#  define _LIBCPP_HAS_NO_CONSTEXPR
-// Can only use constexpr in c++11 mode.
-#elif !defined(__GXX_EXPERIMENTAL_CXX0X__) && __cplusplus < 201103L
-#  define _LIBCPP_HAS_NO_CONSTEXPR
-#endif
-
 // Determine if GCC supports relaxed constexpr
 #if !defined(__cpp_constexpr) || __cpp_constexpr < 201304L
 #define _LIBCPP_HAS_NO_CXX14_CONSTEXPR
 #endif
 
-// GCC 5 will support variable templates
+// GCC 5 supports variable templates
 #if !defined(__cpp_variable_templates) || __cpp_variable_templates < 201304L
 #define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
 #endif
 
-#ifndef __GXX_EXPERIMENTAL_CXX0X__
-
-#define _LIBCPP_HAS_NO_DECLTYPE
-#define _LIBCPP_HAS_NO_NULLPTR
-#define _LIBCPP_HAS_NO_UNICODE_CHARS
-#define _LIBCPP_HAS_NO_VARIADICS
-#define _LIBCPP_HAS_NO_RVALUE_REFERENCES
-#define _LIBCPP_HAS_NO_STRONG_ENUMS
-#define _LIBCPP_HAS_NO_NOEXCEPT
-
-#else  // __GXX_EXPERIMENTAL_CXX0X__
-
-#if _GNUC_VER < 403
-#define _LIBCPP_HAS_NO_RVALUE_REFERENCES
-#endif
-
-
-#if _GNUC_VER < 404
-#define _LIBCPP_HAS_NO_DECLTYPE
-#define _LIBCPP_HAS_NO_UNICODE_CHARS
-#define _LIBCPP_HAS_NO_VARIADICS
-#define _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
-#endif  // _GNUC_VER < 404
-
-#if _GNUC_VER < 406
-#define _LIBCPP_HAS_NO_NOEXCEPT
-#define _LIBCPP_HAS_NO_NULLPTR
-#endif
-
-#endif  // __GXX_EXPERIMENTAL_CXX0X__
-
 #if !defined(_LIBCPP_HAS_NO_ASAN) && !defined(__SANITIZE_ADDRESS__)
 #define _LIBCPP_HAS_NO_ASAN
 #endif
@@ -597,16 +533,12 @@ typedef __char32_t char32_t;
 #error "MSVC versions prior to Visual Studio 2015 are not supported"
 #endif
 
-#define _LIBCPP_HAS_IS_BASE_OF
-#define _LIBCPP_HAS_NO_CONSTEXPR
 #define _LIBCPP_HAS_NO_CXX14_CONSTEXPR
 #define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
-#define _LIBCPP_HAS_NO_NOEXCEPT
 #define __alignof__ __alignof
 #define _LIBCPP_NORETURN __declspec(noreturn)
 #define _ALIGNAS(x) __declspec(align(x))
 #define _ALIGNAS_TYPE(x) alignas(x)
-#define _LIBCPP_HAS_NO_VARIADICS
 
 #define _LIBCPP_WEAK
 
@@ -623,12 +555,7 @@ typedef __char32_t char32_t;
 #define _ATTRIBUTE(x) __attribute__((x))
 #define _LIBCPP_NORETURN __attribute__((noreturn))
 
-#define _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
-#define _LIBCPP_HAS_NO_NOEXCEPT
-#define _LIBCPP_HAS_NO_NULLPTR
 #define _LIBCPP_HAS_NO_UNICODE_CHARS
-#define _LIBCPP_HAS_IS_BASE_OF
-#define _LIBCPP_HAS_IS_FINAL
 #define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
 
 #if defined(_AIX)
@@ -659,8 +586,13 @@ typedef __char32_t char32_t;
 #  define _LIBCPP_EXPORTED_FROM_ABI
 #elif defined(_LIBCPP_BUILDING_LIBRARY)
 #  define _LIBCPP_DLL_VIS __declspec(dllexport)
-#  define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
+#  if defined(__MINGW32__)
-#  define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS _LIBCPP_DLL_VIS
+#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
+#    define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
+#  else
+#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
+#    define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS _LIBCPP_DLL_VIS
+#  endif
 #  define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_DLL_VIS
 #  define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllexport)
 #else
@@ -777,7 +709,7 @@ typedef __char32_t char32_t;
 #else
    // Try to approximate the effect of exclude_from_explicit_instantiation
    // (which is that entities are not assumed to be provided by explicit
-   // template instantitations in the dylib) by always inlining those entities.
+   // template instantiations in the dylib) by always inlining those entities.
 #  define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION _LIBCPP_ALWAYS_INLINE
 #endif
 
@@ -789,6 +721,16 @@ typedef __char32_t char32_t;
 #  endif
 #endif
 
+#ifndef _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT
+# ifdef _LIBCPP_OBJECT_FORMAT_COFF // Windows binaries can't merge typeinfos.
+# define _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT 0
+#else
+// TODO: This isn't strictly correct on ELF platforms due to llvm.org/PR37398
+// And we should consider defaulting to OFF.
+# define _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT 1
+#endif
+#endif
+
 #ifndef _LIBCPP_HIDE_FROM_ABI
 #  if _LIBCPP_HIDE_FROM_ABI_PER_TU
 #    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_INTERNAL_LINKAGE
@@ -843,22 +785,6 @@ _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_END_NAMESPACE_STD
 #  define _NOEXCEPT_(x)
 #endif
 
-#if defined(_LIBCPP_DEBUG_USE_EXCEPTIONS)
-#  if !defined(_LIBCPP_DEBUG)
-#    error cannot use _LIBCPP_DEBUG_USE_EXCEPTIONS unless _LIBCPP_DEBUG is defined
-#  endif
-#  ifdef _LIBCPP_HAS_NO_NOEXCEPT
-#    define _NOEXCEPT_DEBUG
-#    define _NOEXCEPT_DEBUG_(x)
-#  else
-#    define _NOEXCEPT_DEBUG noexcept(false)
-#    define _NOEXCEPT_DEBUG_(x) noexcept(false)
-#  endif
-#else
-#  define _NOEXCEPT_DEBUG _NOEXCEPT
-#  define _NOEXCEPT_DEBUG_(x) _NOEXCEPT_(x)
-#endif
-
 #ifdef _LIBCPP_HAS_NO_UNICODE_CHARS
 typedef unsigned short char16_t;
 typedef unsigned int   char32_t;
@@ -869,30 +795,11 @@ typedef unsigned int   char32_t;
 #endif
 
 #ifdef _LIBCPP_CXX03_LANG
-#  if __has_extension(c_static_assert)
+# define static_assert(...) _Static_assert(__VA_ARGS__)
-#    define static_assert(__b, __m) _Static_assert(__b, __m)
+# define decltype(...) __decltype(__VA_ARGS__)
-#  else
-extern "C++" {
-template <bool> struct __static_assert_test;
-template <> struct __static_assert_test<true> {};
-template <unsigned> struct __static_assert_check {};
-}
-#    define static_assert(__b, __m) \
-       typedef __static_assert_check<sizeof(__static_assert_test<(__b)>)> \
-       _LIBCPP_CONCAT(__t, __LINE__)
-#  endif // __has_extension(c_static_assert)
 #endif  // _LIBCPP_CXX03_LANG
 
-#ifdef _LIBCPP_HAS_NO_DECLTYPE
+#ifdef _LIBCPP_CXX03_LANG
-// GCC 4.6 provides __decltype in all standard modes.
-#  if __has_keyword(__decltype) || _LIBCPP_CLANG_VER >= 304 || _GNUC_VER >= 406
-#    define decltype(__x) __decltype(__x)
-#  else
-#    define decltype(__x) __typeof__(__x)
-#  endif
-#endif
-
-#ifdef _LIBCPP_HAS_NO_CONSTEXPR
 #  define _LIBCPP_CONSTEXPR
 #else
 #  define _LIBCPP_CONSTEXPR constexpr
@@ -911,9 +818,9 @@ template <unsigned> struct __static_assert_check {};
 #endif
 
 #ifdef __GNUC__
-#  define _NOALIAS __attribute__((__malloc__))
+#  define _LIBCPP_NOALIAS __attribute__((__malloc__))
 #else
-#  define _NOALIAS
+#  define _LIBCPP_NOALIAS
 #endif
 
 #if __has_feature(cxx_explicit_conversions) || defined(__IBMCPP__) || \
@@ -966,10 +873,6 @@ template <unsigned> struct __static_assert_check {};
 #define _LIBCPP_EXTERN_TEMPLATE2(...) extern template __VA_ARGS__;
 #endif
 
-#if defined(__APPLE__) && defined(__LP64__) && !defined(__x86_64__)
-#define _LIBCPP_NONUNIQUE_RTTI_BIT (1ULL << 63)
-#endif
-
 #if defined(__APPLE__) || defined(__FreeBSD__) || defined(_LIBCPP_MSVCRT_LIKE) || \
     defined(__sun__) || defined(__NetBSD__) || defined(__CloudABI__)
 #define _LIBCPP_LOCALE__L_EXTENSIONS 1
@@ -990,13 +893,10 @@ template <unsigned> struct __static_assert_check {};
 // for align_val_t were added in 19.12, aka VS 2017 version 15.3.
 #if defined(_LIBCPP_MSVCRT) && defined(_MSC_VER) && _MSC_VER < 1912
 #  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
-#elif defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#elif defined(_LIBCPP_ABI_VCRUNTIME) && !defined(__cpp_aligned_new)
-#  define _LIBCPP_DEFER_NEW_TO_VCRUNTIME
+   // We're deferring to Microsoft's STL to provide aligned new et al. We don't
-#  if !defined(__cpp_aligned_new)
+   // have it unless the language feature test macro is defined.
-     // We're defering to Microsoft's STL to provide aligned new et al. We don't
+#  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
-     // have it unless the language feature test macro is defined.
-#    define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
-#  endif
 #endif
 
 #if defined(__APPLE__)
@@ -1025,8 +925,10 @@ template <unsigned> struct __static_assert_check {};
 #endif
 
 // Deprecation macros.
-// Deprecations warnings are only enabled when _LIBCPP_ENABLE_DEPRECATION_WARNINGS is defined.
+//
-#if defined(_LIBCPP_ENABLE_DEPRECATION_WARNINGS)
+// Deprecations warnings are always enabled, except when users explicitly opt-out
+// by defining _LIBCPP_DISABLE_DEPRECATION_WARNINGS.
+#if !defined(_LIBCPP_DISABLE_DEPRECATION_WARNINGS)
 #  if __has_attribute(deprecated)
 #    define _LIBCPP_DEPRECATED __attribute__ ((deprecated))
 #  elif _LIBCPP_STD_VER > 11
@@ -1128,6 +1030,12 @@ template <unsigned> struct __static_assert_check {};
 #endif
 #endif
 
+#if __has_attribute(no_destroy)
+#  define _LIBCPP_NO_DESTROY __attribute__((__no_destroy__))
+#else
+#  define _LIBCPP_NO_DESTROY
+#endif
+
 #ifndef _LIBCPP_HAS_NO_ASAN
 _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
   const void *, const void *, const void *, const void *);
@@ -1158,6 +1066,7 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
     !defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
 #  if defined(__FreeBSD__) || \
       defined(__Fuchsia__) || \
+      defined(__wasi__) || \
       defined(__NetBSD__) || \
       defined(__linux__) || \
       defined(__GNU__) || \
@@ -1188,6 +1097,23 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
        _LIBCPP_HAS_NO_THREADS is defined.
 #endif
 
+// The Apple, glibc, and Bionic implementation of pthreads implements
+// pthread_mutex_destroy as nop for regular mutexes. Additionally, Win32
+// mutexes have no destroy mechanism.
+// TODO(EricWF): Enable this optimization on Apple and Bionic platforms after
+// speaking to their respective stakeholders.
+#if (defined(_LIBCPP_HAS_THREAD_API_PTHREAD) && defined(__GLIBC__)) \
+  || defined(_LIBCPP_HAS_THREAD_API_WIN32)
+# define _LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION
+#endif
+
+// Destroying a condvar is a nop on Windows.
+// TODO(EricWF): This is potentially true for some pthread implementations
+// as well.
+#if defined(_LIBCPP_HAS_THREAD_API_WIN32)
+# define _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION
+#endif
+
 // Systems that use capability-based security (FreeBSD with Capsicum,
 // Nuxi CloudABI) may only provide local filesystem access (using *at()).
 // Functions like open(), rename(), unlink() and stat() should not be
@@ -1204,7 +1130,7 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 #endif
 
 #if defined(__BIONIC__) || defined(__CloudABI__) ||                            \
-    defined(__Fuchsia__) || defined(_LIBCPP_HAS_MUSL_LIBC)
+    defined(__Fuchsia__) || defined(__wasi__) || defined(_LIBCPP_HAS_MUSL_LIBC)
 #define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
 #endif
 
@@ -1216,13 +1142,22 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 
 #if __has_feature(cxx_atomic) || __has_extension(c_atomic) || __has_keyword(_Atomic)
 #  define _LIBCPP_HAS_C_ATOMIC_IMP
-#elif _GNUC_VER > 407
+#elif defined(_LIBCPP_COMPILER_GCC)
 #  define _LIBCPP_HAS_GCC_ATOMIC_IMP
 #endif
 
-#if (!defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_GCC_ATOMIC_IMP)) \
+#if (!defined(_LIBCPP_HAS_C_ATOMIC_IMP) && \
+     !defined(_LIBCPP_HAS_GCC_ATOMIC_IMP) && \
+     !defined(_LIBCPP_HAS_EXTERNAL_ATOMIC_IMP)) \
      || defined(_LIBCPP_HAS_NO_THREADS)
-#define _LIBCPP_HAS_NO_ATOMIC_HEADER
+#  define _LIBCPP_HAS_NO_ATOMIC_HEADER
+#else
+#  ifndef _LIBCPP_ATOMIC_FLAG_TYPE
+#    define _LIBCPP_ATOMIC_FLAG_TYPE bool
+#  endif
+#  ifdef _LIBCPP_FREESTANDING
+#    define _LIBCPP_ATOMIC_ONLY_USE_BUILTINS
+#  endif
 #endif
 
 #ifndef _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
@@ -1250,6 +1185,10 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 #define _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
 #endif
 
+#if !__has_builtin(__builtin_is_constant_evaluated) && _GNUC_VER < 900
+#define _LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED
+#endif
+
 #if !defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
 #  if defined(_LIBCPP_MSVCRT) || defined(_NEWLIB_VERSION)
 #    define _LIBCPP_HAS_NO_OFF_T_FUNCTIONS
@@ -1277,6 +1216,21 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 #  define _LIBCPP_FALLTHROUGH() ((void)0)
 #endif
 
+#if __has_attribute(__nodebug__)
+#define _LIBCPP_NODEBUG __attribute__((__nodebug__))
+#else
+#define _LIBCPP_NODEBUG
+#endif
+
+#ifndef _LIBCPP_NODEBUG_TYPE
+#if __has_attribute(__nodebug__) && \
+    (defined(_LIBCPP_COMPILER_CLANG) && _LIBCPP_CLANG_VER >= 900)
+#define _LIBCPP_NODEBUG_TYPE __attribute__((nodebug))
+#else
+#define _LIBCPP_NODEBUG_TYPE
+#endif
+#endif // !defined(_LIBCPP_NODEBUG_TYPE)
+
 #if defined(_LIBCPP_ABI_MICROSOFT) && \
     (defined(_LIBCPP_COMPILER_MSVC) || __has_declspec_attribute(empty_bases))
 #  define _LIBCPP_DECLSPEC_EMPTY_BASES __declspec(empty_bases)
@@ -1312,7 +1266,8 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 #if !defined(_LIBCPP_BUILDING_LIBRARY) &&                                      \
     !defined(_LIBCPP_DISABLE_AVAILABILITY) &&                                  \
     __has_feature(attribute_availability_with_strict) &&                       \
-    __has_feature(attribute_availability_in_templates)
+    __has_feature(attribute_availability_in_templates) &&                      \
+    __has_extension(pragma_clang_attribute_external_declaration)
 #  ifdef __APPLE__
 #    define _LIBCPP_USE_AVAILABILITY_APPLE
 #  endif
@@ -1355,6 +1310,21 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 #  define _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR                               \
      __attribute__((availability(macosx,strict,introduced=10.9)))              \
      __attribute__((availability(ios,strict,introduced=7.0)))
+#  define _LIBCPP_AVAILABILITY_FILESYSTEM                                      \
+     __attribute__((availability(macosx,strict,introduced=10.15)))             \
+     __attribute__((availability(ios,strict,introduced=13.0)))                 \
+     __attribute__((availability(tvos,strict,introduced=13.0)))                \
+     __attribute__((availability(watchos,strict,introduced=6.0)))
+#  define _LIBCPP_AVAILABILITY_FILESYSTEM_PUSH                                 \
+     _Pragma("clang attribute push(__attribute__((availability(macosx,strict,introduced=10.15))), apply_to=any(function,record))") \
+     _Pragma("clang attribute push(__attribute__((availability(ios,strict,introduced=13.0))), apply_to=any(function,record))")     \
+     _Pragma("clang attribute push(__attribute__((availability(tvos,strict,introduced=13.0))), apply_to=any(function,record))")    \
+     _Pragma("clang attribute push(__attribute__((availability(watchos,strict,introduced=6.0))), apply_to=any(function,record))")
+#  define _LIBCPP_AVAILABILITY_FILESYSTEM_POP                                  \
+     _Pragma("clang attribute pop")                                            \
+     _Pragma("clang attribute pop")                                            \
+     _Pragma("clang attribute pop")                                            \
+     _Pragma("clang attribute pop")
 #else
 #  define _LIBCPP_AVAILABILITY_SHARED_MUTEX
 #  define _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS
@@ -1366,6 +1336,9 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 #  define _LIBCPP_AVAILABILITY_TYPEINFO_VTABLE
 #  define _LIBCPP_AVAILABILITY_LOCALE_CATEGORY
 #  define _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
+#  define _LIBCPP_AVAILABILITY_FILESYSTEM
+#  define _LIBCPP_AVAILABILITY_FILESYSTEM_PUSH
+#  define _LIBCPP_AVAILABILITY_FILESYSTEM_POP
 #endif
 
 // Define availability that depends on _LIBCPP_NO_EXCEPTIONS.

lib/libcxx/include/__config_site.in

@@ -1,9 +1,8 @@
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -28,6 +27,7 @@
 #cmakedefine _LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL
 #cmakedefine _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS
 #cmakedefine _LIBCPP_NO_VCRUNTIME
+#cmakedefine01 _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT
 #cmakedefine _LIBCPP_ABI_NAMESPACE @_LIBCPP_ABI_NAMESPACE@
 
 @_LIBCPP_ABI_DEFINES@

lib/libcxx/include/__debug

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- __debug ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -12,6 +11,7 @@
 #define _LIBCPP_DEBUG_H
 
 #include <__config>
+#include <iosfwd>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
@@ -25,7 +25,6 @@
 #   include <cstdlib>
 #   include <cstdio>
 #   include <cstddef>
-#   include <exception>
 #endif
 
 #if _LIBCPP_DEBUG_LEVEL >= 1 && !defined(_LIBCPP_ASSERT)
@@ -50,10 +49,6 @@
 #define _LIBCPP_DEBUG_MODE(...) ((void)0)
 #endif
 
-#if _LIBCPP_DEBUG_LEVEL < 1
-class _LIBCPP_EXCEPTION_ABI __libcpp_debug_exception;
-#endif
-
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 struct _LIBCPP_TEMPLATE_VIS __libcpp_debug_info {
@@ -63,6 +58,9 @@ struct _LIBCPP_TEMPLATE_VIS __libcpp_debug_info {
   _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
   __libcpp_debug_info(const char* __f, int __l, const char* __p, const char* __m)
     : __file_(__f), __line_(__l), __pred_(__p), __msg_(__m) {}
+
+  _LIBCPP_FUNC_VIS std::string what() const;
+
   const char* __file_;
   int __line_;
   const char* __pred_;
@@ -80,38 +78,11 @@ extern _LIBCPP_EXPORTED_FROM_ABI __libcpp_debug_function_type __libcpp_debug_fun
 _LIBCPP_NORETURN _LIBCPP_FUNC_VIS
 void __libcpp_abort_debug_function(__libcpp_debug_info const&);
 
-/// __libcpp_throw_debug_function - A debug handler that throws
-///   an instance of __libcpp_debug_exception when called.
- _LIBCPP_NORETURN _LIBCPP_FUNC_VIS
-void __libcpp_throw_debug_function(__libcpp_debug_info const&);
-
 /// __libcpp_set_debug_function - Set the debug handler to the specified
 ///    function.
 _LIBCPP_FUNC_VIS
 bool __libcpp_set_debug_function(__libcpp_debug_function_type __func);
 
-// Setup the throwing debug handler during dynamic initialization.
-#if _LIBCPP_DEBUG_LEVEL >= 1 && defined(_LIBCPP_DEBUG_USE_EXCEPTIONS)
-# if defined(_LIBCPP_NO_EXCEPTIONS)
-#   error _LIBCPP_DEBUG_USE_EXCEPTIONS cannot be used when exceptions are disabled.
-# endif
-static bool __init_dummy = __libcpp_set_debug_function(__libcpp_throw_debug_function);
-#endif
-
-#if _LIBCPP_DEBUG_LEVEL >= 1 || defined(_LIBCPP_BUILDING_LIBRARY)
-class _LIBCPP_EXCEPTION_ABI __libcpp_debug_exception : public exception {
-public:
-  __libcpp_debug_exception() _NOEXCEPT;
-  explicit __libcpp_debug_exception(__libcpp_debug_info const& __i);
-  __libcpp_debug_exception(__libcpp_debug_exception const&);
-  ~__libcpp_debug_exception() _NOEXCEPT;
-  const char* what() const _NOEXCEPT;
-private:
-  struct __libcpp_debug_exception_imp;
-  __libcpp_debug_exception_imp *__imp_;
-};
-#endif
-
 #if _LIBCPP_DEBUG_LEVEL >= 2 || defined(_LIBCPP_BUILDING_LIBRARY)
 
 struct _LIBCPP_TYPE_VIS __c_node;
@@ -251,16 +222,22 @@ public:
     __db_c_const_iterator __c_end() const;
     __db_i_const_iterator __i_end() const;
 
+    typedef __c_node*(_InsertConstruct)(void*, void*, __c_node*);
+
+    template <class _Cont>
+    _LIBCPP_INLINE_VISIBILITY static __c_node* __create_C_node(void *__mem, void *__c, __c_node *__next) {
+        return ::new(__mem) _C_node<_Cont>(__c, __next);
+    }
+
     template <class _Cont>
     _LIBCPP_INLINE_VISIBILITY
     void __insert_c(_Cont* __c)
     {
-        __c_node* __n = __insert_c(static_cast<void*>(__c));
+        __insert_c(static_cast<void*>(__c), &__create_C_node<_Cont>);
-        ::new(__n) _C_node<_Cont>(__n->__c_, __n->__next_);
     }
 
     void __insert_i(void* __i);
-    __c_node* __insert_c(void* __c);
+    void __insert_c(void* __c, _InsertConstruct* __fn);
     void __erase_c(void* __c);
 
     void __insert_ic(void* __i, const void* __c);

lib/libcxx/include/__errc

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- __errc ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/__functional_03

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/__functional_base

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -126,7 +125,7 @@ struct __weak_result_type_imp // bool is true
     : public __maybe_derive_from_unary_function<_Tp>,
       public __maybe_derive_from_binary_function<_Tp>
 {
-    typedef typename _Tp::result_type result_type;
+    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::result_type result_type;
 };
 
 template <class _Tp>
@@ -147,19 +146,19 @@ struct __weak_result_type
 template <class _Rp>
 struct __weak_result_type<_Rp ()>
 {
-    typedef _Rp result_type;
+    typedef _LIBCPP_NODEBUG_TYPE  _Rp result_type;
 };
 
 template <class _Rp>
 struct __weak_result_type<_Rp (&)()>
 {
-    typedef _Rp result_type;
+    typedef _LIBCPP_NODEBUG_TYPE  _Rp result_type;
 };
 
 template <class _Rp>
 struct __weak_result_type<_Rp (*)()>
 {
-    typedef _Rp result_type;
+    typedef _LIBCPP_NODEBUG_TYPE  _Rp result_type;
 };
 
 // 1 argument case
@@ -611,7 +610,7 @@ _LIBCPP_INLINE_VAR constexpr size_t uses_allocator_v = uses_allocator<_Tp, _Allo
 template <class _Tp, class _Alloc, class ..._Args>
 struct __uses_alloc_ctor_imp
 {
-    typedef typename __uncvref<_Alloc>::type _RawAlloc;
+    typedef _LIBCPP_NODEBUG_TYPE typename __uncvref<_Alloc>::type _RawAlloc;
     static const bool __ua = uses_allocator<_Tp, _RawAlloc>::value;
     static const bool __ic =
         is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value;

lib/libcxx/include/__functional_base_03

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/__hash_table

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -123,7 +122,7 @@ inline _LIBCPP_INLINE_VISIBILITY
 size_t
 __next_hash_pow2(size_t __n)
 {
-    return __n < 2 ? __n : (size_t(1) << (std::numeric_limits<size_t>::digits - __clz(__n-1)));
+    return __n < 2 ? __n : (size_t(1) << (std::numeric_limits<size_t>::digits - __libcpp_clz(__n-1)));
 }
 
 
@@ -876,9 +875,9 @@ struct __enforce_unordered_container_requirements {
 template <class _Key, class _Hash, class _Equal>
 #ifndef _LIBCPP_CXX03_LANG
     _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Equal const&, _Key const&, _Key const&>::value,
-    "the specified comparator type does not provide a const call operator")
+    "the specified comparator type does not provide a viable const call operator")
     _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Hash const&, _Key const&>::value,
-    "the specified hash functor does not provide a const call operator")
+    "the specified hash functor does not provide a viable const call operator")
 #endif
 typename __enforce_unordered_container_requirements<_Key, _Hash, _Equal>::type
 __diagnose_unordered_container_requirements(int);
@@ -1261,7 +1260,7 @@ public:
 
     void swap(__hash_table& __u)
 #if _LIBCPP_STD_VER <= 11
-        _NOEXCEPT_DEBUG_(
+        _NOEXCEPT_(
             __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
             && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
                   || __is_nothrow_swappable<__pointer_allocator>::value)
@@ -1269,7 +1268,7 @@ public:
                   || __is_nothrow_swappable<__node_allocator>::value)
             );
 #else
-     _NOEXCEPT_DEBUG_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value);
+     _NOEXCEPT_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value);
 #endif
 
     _LIBCPP_INLINE_VISIBILITY
@@ -2249,7 +2248,7 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_unique(
         return _InsertReturnType{end(), false, _NodeHandle()};
     pair<iterator, bool> __result = __node_insert_unique(__nh.__ptr_);
     if (__result.second)
-        __nh.__release();
+        __nh.__release_ptr();
     return _InsertReturnType{__result.first, __result.second, _VSTD::move(__nh)};
 }
 
@@ -2264,7 +2263,7 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_unique(
         return end();
     pair<iterator, bool> __result = __node_insert_unique(__nh.__ptr_);
     if (__result.second)
-        __nh.__release();
+        __nh.__release_ptr();
     return __result.first;
 }
 
@@ -2328,7 +2327,7 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_multi(
     if (__nh.empty())
         return end();
     iterator __result = __node_insert_multi(__nh.__ptr_);
-    __nh.__release();
+    __nh.__release_ptr();
     return __result;
 }
 
@@ -2342,7 +2341,7 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_multi(
     if (__nh.empty())
         return end();
     iterator __result = __node_insert_multi(__hint, __nh.__ptr_);
-    __nh.__release();
+    __nh.__release_ptr();
     return __result;
 }
 
@@ -2372,6 +2371,7 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_merge_multi(
 template <class _Tp, class _Hash, class _Equal, class _Alloc>
 void
 __hash_table<_Tp, _Hash, _Equal, _Alloc>::rehash(size_type __n)
+_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
 {
     if (__n == 1)
         __n = 2;
@@ -2807,7 +2807,7 @@ template <class _Tp, class _Hash, class _Equal, class _Alloc>
 void
 __hash_table<_Tp, _Hash, _Equal, _Alloc>::swap(__hash_table& __u)
 #if _LIBCPP_STD_VER <= 11
-    _NOEXCEPT_DEBUG_(
+    _NOEXCEPT_(
         __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
         && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
               || __is_nothrow_swappable<__pointer_allocator>::value)
@@ -2815,7 +2815,7 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::swap(__hash_table& __u)
               || __is_nothrow_swappable<__node_allocator>::value)
             )
 #else
-  _NOEXCEPT_DEBUG_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value)
+  _NOEXCEPT_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value)
 #endif
 {
     _LIBCPP_ASSERT(__node_traits::propagate_on_container_swap::value ||

lib/libcxx/include/__libcpp_version

@@ -1 +1 @@
-8000
+9000

lib/libcxx/include/__locale

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -20,6 +19,7 @@
 #include <cctype>
 #include <locale.h>
 #if defined(_LIBCPP_MSVCRT_LIKE)
+# include <cstring>
 # include <support/win32/locale_win32.h>
 #elif defined(_AIX)
 # include <support/ibm/xlocale.h>
@@ -35,6 +35,9 @@
 # include <xlocale.h>
 #elif defined(__Fuchsia__)
 # include <support/fuchsia/xlocale.h>
+#elif defined(__wasi__)
+// WASI libc uses musl's locales support.
+# include <support/musl/xlocale.h>
 #elif defined(_LIBCPP_HAS_MUSL_LIBC)
 # include <support/musl/xlocale.h>
 #endif
@@ -64,28 +67,41 @@ private:
 #elif defined(_LIBCPP_MSVCRT_LIKE)
 struct __libcpp_locale_guard {
     __libcpp_locale_guard(locale_t __l) :
-        __status(_configthreadlocale(_ENABLE_PER_THREAD_LOCALE)),
+        __status(_configthreadlocale(_ENABLE_PER_THREAD_LOCALE)) {
-        __locale_collate(setlocale(LC_COLLATE, __l.__get_locale())),
+      // Setting the locale can be expensive even when the locale given is
-        __locale_ctype(setlocale(LC_CTYPE, __l.__get_locale())),
+      // already the current locale, so do an explicit check to see if the
-        __locale_monetary(setlocale(LC_MONETARY, __l.__get_locale())),
+      // current locale is already the one we want.
-        __locale_numeric(setlocale(LC_NUMERIC, __l.__get_locale())),
+      const char* __lc = __setlocale(nullptr);
-        __locale_time(setlocale(LC_TIME, __l.__get_locale()))
+      // If every category is the same, the locale string will simply be the
-        // LC_MESSAGES is not supported on Windows.
+      // locale name, otherwise it will be a semicolon-separated string listing
-    {}
+      // each category.  In the second case, we know at least one category won't
+      // be what we want, so we only have to check the first case.
+      if (strcmp(__l.__get_locale(), __lc) != 0) {
+        __locale_all = _strdup(__lc);
+        if (__locale_all == nullptr)
+          __throw_bad_alloc();
+        __setlocale(__l.__get_locale());
+      }
+    }
     ~__libcpp_locale_guard() {
-        setlocale(LC_COLLATE, __locale_collate);
+      // The CRT documentation doesn't explicitly say, but setlocale() does the
-        setlocale(LC_CTYPE, __locale_ctype);
+      // right thing when given a semicolon-separated list of locale settings
-        setlocale(LC_MONETARY, __locale_monetary);
+      // for the different categories in the same format as returned by
-        setlocale(LC_NUMERIC, __locale_numeric);
+      // setlocale(LC_ALL, nullptr).
-        setlocale(LC_TIME, __locale_time);
+      if (__locale_all != nullptr) {
-        _configthreadlocale(__status);
+        __setlocale(__locale_all);
+        free(__locale_all);
+      }
+      _configthreadlocale(__status);
+    }
+    static const char* __setlocale(const char* __locale) {
+      const char* __new_locale = setlocale(LC_ALL, __locale);
+      if (__new_locale == nullptr)
+        __throw_bad_alloc();
+      return __new_locale;
     }
     int __status;
-    char* __locale_collate;
+    char* __locale_all = nullptr;
-    char* __locale_ctype;
-    char* __locale_monetary;
-    char* __locale_numeric;
-    char* __locale_time;
 };
 #endif
 
@@ -255,7 +271,10 @@ public:
         return do_compare(__lo1, __hi1, __lo2, __hi2);
     }
 
+    // FIXME(EricWF): The _LIBCPP_ALWAYS_INLINE is needed on Windows to work
+    // around a dllimport bug that expects an external instantiation.
     _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_ALWAYS_INLINE
     string_type transform(const char_type* __lo, const char_type* __hi) const
     {
         return do_transform(__lo, __hi);
@@ -389,6 +408,11 @@ public:
     static const mask punct  = _ISpunct;
     static const mask xdigit = _ISxdigit;
     static const mask blank  = _ISblank;
+#if defined(__mips__)
+    static const mask __regex_word = static_cast<char_class_type>(_ISbit(15));
+#else
+    static const mask __regex_word = 0x80;
+#endif
 #elif defined(_LIBCPP_MSVCRT_LIKE)
     typedef unsigned short mask;
     static const mask space  = _SPACE;
@@ -401,6 +425,7 @@ public:
     static const mask punct  = _PUNCT;
     static const mask xdigit = _HEX;
     static const mask blank  = _BLANK;
+    static const mask __regex_word = 0x80;
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
 #elif defined(__APPLE__) || defined(__FreeBSD__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__)
 # ifdef __APPLE__
@@ -422,8 +447,12 @@ public:
 
 # if defined(__NetBSD__)
     static const mask blank  = _CTYPE_BL;
+    // NetBSD defines classes up to 0x2000
+    // see sys/ctype_bits.h, _CTYPE_Q
+    static const mask __regex_word = 0x8000;
 # else
     static const mask blank  = _CTYPE_B;
+    static const mask __regex_word = 0x80;
 # endif
 #elif defined(__sun__) || defined(_AIX)
     typedef unsigned int mask;
@@ -437,6 +466,7 @@ public:
     static const mask punct  = _ISPUNCT;
     static const mask xdigit = _ISXDIGIT;
     static const mask blank  = _ISBLANK;
+    static const mask __regex_word = 0x80;
 #elif defined(_NEWLIB_VERSION)
     // Same type as Newlib's _ctype_ array in newlib/libc/include/ctype.h.
     typedef char mask;
@@ -450,6 +480,7 @@ public:
     static const mask punct  = _P;
     static const mask xdigit = _X | _N;
     static const mask blank  = _B;
+    static const mask __regex_word = 0x80;
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_ALPHA
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_XDIGIT
@@ -465,6 +496,7 @@ public:
     static const mask punct  = 1<<7;
     static const mask xdigit = 1<<8;
     static const mask blank  = 1<<9;
+    static const mask __regex_word = 1<<10;
 #endif
     static const mask alnum  = alpha | digit;
     static const mask graph  = alnum | punct;
@@ -1230,8 +1262,6 @@ _LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<w
 _LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char16_t, char, mbstate_t>)
 _LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char32_t, char, mbstate_t>)
 
-_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_runtime_error(const char*);
-
 template <size_t _Np>
 struct __narrow_to_utf8
 {

lib/libcxx/include/__mutex_base

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -37,28 +36,24 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 #  endif
 #endif  // _LIBCPP_THREAD_SAFETY_ANNOTATION
 
+
 class _LIBCPP_TYPE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(capability("mutex")) mutex
 {
-#ifndef _LIBCPP_CXX03_LANG
     __libcpp_mutex_t __m_ = _LIBCPP_MUTEX_INITIALIZER;
-#else
-    __libcpp_mutex_t __m_;
-#endif
 
 public:
     _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_CXX03_LANG
+    _LIBCPP_CONSTEXPR mutex() = default;
-    constexpr mutex() = default;
+
+    mutex(const mutex&) = delete;
+    mutex& operator=(const mutex&) = delete;
+
+#if defined(_LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION)
+    ~mutex() = default;
 #else
-    mutex() _NOEXCEPT {__m_ = (__libcpp_mutex_t)_LIBCPP_MUTEX_INITIALIZER;}
+    ~mutex() _NOEXCEPT;
 #endif
-    ~mutex();
 
-private:
-    mutex(const mutex&);// = delete;
-    mutex& operator=(const mutex&);// = delete;
-
-public:
     void lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability());
     bool try_lock() _NOEXCEPT _LIBCPP_THREAD_SAFETY_ANNOTATION(try_acquire_capability(true));
     void unlock() _NOEXCEPT _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability());
@@ -287,26 +282,20 @@ _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(cv_status)
 
 class _LIBCPP_TYPE_VIS condition_variable
 {
-#ifndef _LIBCPP_CXX03_LANG
     __libcpp_condvar_t __cv_ = _LIBCPP_CONDVAR_INITIALIZER;
-#else
-    __libcpp_condvar_t __cv_;
-#endif
-
 public:
     _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_CXX03_LANG
+    _LIBCPP_CONSTEXPR condition_variable() _NOEXCEPT = default;
-    constexpr condition_variable() _NOEXCEPT = default;
+
+#ifdef _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION
+    ~condition_variable() = default;
 #else
-    condition_variable() _NOEXCEPT {__cv_ = (__libcpp_condvar_t)_LIBCPP_CONDVAR_INITIALIZER;}
-#endif
     ~condition_variable();
+#endif
 
-private:
+    condition_variable(const condition_variable&) = delete;
-    condition_variable(const condition_variable&); // = delete;
+    condition_variable& operator=(const condition_variable&) = delete;
-    condition_variable& operator=(const condition_variable&); // = delete;
 
-public:
     void notify_one() _NOEXCEPT;
     void notify_all() _NOEXCEPT;
 

lib/libcxx/include/__node_handle

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -57,7 +56,7 @@ private:
     optional<allocator_type> __alloc_;
 
     _LIBCPP_INLINE_VISIBILITY
-    void __release()
+    void __release_ptr()
     {
         __ptr_ = nullptr;
         __alloc_ = _VSTD::nullopt;
@@ -194,8 +193,7 @@ using __map_node_handle =
     __basic_node_handle< _NodeType, _Alloc, __map_node_handle_specifics>;
 
 template <class _Iterator, class _NodeType>
-_LIBCPP_TEMPLATE_VIS
+struct _LIBCPP_TEMPLATE_VIS __insert_return_type
-struct __insert_return_type
 {
     _Iterator position;
     bool inserted;

lib/libcxx/include/__nullptr

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- __nullptr --------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/__sso_allocator

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/__std_stream

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/__string

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- __string ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is distributed under the University of Illinois Open Source
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/__threading_support

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -23,6 +22,8 @@
 # include <__external_threading>
 #elif !defined(_LIBCPP_HAS_NO_THREADS)
 
+typedef ::timespec __libcpp_timespec_t;
+
 #if defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
 # include <pthread.h>
 # include <sched.h>
@@ -149,7 +150,7 @@ int __libcpp_condvar_wait(__libcpp_condvar_t* __cv, __libcpp_mutex_t* __m);
 
 _LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
 int __libcpp_condvar_timedwait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m,
-                               timespec *__ts);
+                               __libcpp_timespec_t *__ts);
 
 _LIBCPP_THREAD_ABI_VISIBILITY
 int __libcpp_condvar_destroy(__libcpp_condvar_t* __cv);
@@ -157,7 +158,7 @@ int __libcpp_condvar_destroy(__libcpp_condvar_t* __cv);
 // Execute once
 _LIBCPP_THREAD_ABI_VISIBILITY
 int __libcpp_execute_once(__libcpp_exec_once_flag *flag,
-                          void (*init_routine)(void));
+                          void (*init_routine)());
 
 // Thread id
 _LIBCPP_THREAD_ABI_VISIBILITY
@@ -288,7 +289,7 @@ int __libcpp_condvar_wait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m)
 }
 
 int __libcpp_condvar_timedwait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m,
-                               timespec *__ts)
+                               __libcpp_timespec_t *__ts)
 {
   return pthread_cond_timedwait(__cv, __m, __ts);
 }
@@ -300,7 +301,7 @@ int __libcpp_condvar_destroy(__libcpp_condvar_t *__cv)
 
 // Execute once
 int __libcpp_execute_once(__libcpp_exec_once_flag *flag,
-                          void (*init_routine)(void)) {
+                          void (*init_routine)()) {
   return pthread_once(flag, init_routine);
 }
 
@@ -357,7 +358,7 @@ void __libcpp_thread_sleep_for(const chrono::nanoseconds& __ns)
 {
    using namespace chrono;
    seconds __s = duration_cast<seconds>(__ns);
-   timespec __ts;
+   __libcpp_timespec_t __ts;
    typedef decltype(__ts.tv_sec) ts_sec;
    _LIBCPP_CONSTEXPR ts_sec __ts_sec_max = numeric_limits<ts_sec>::max();
 

lib/libcxx/include/__tree

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -27,6 +26,13 @@ _LIBCPP_PUSH_MACROS
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+#if defined(__GNUC__) && !defined(__clang__) // gcc.gnu.org/PR37804
+template <class, class, class, class> class _LIBCPP_TEMPLATE_VIS map;
+template <class, class, class, class> class _LIBCPP_TEMPLATE_VIS multimap;
+template <class, class, class> class _LIBCPP_TEMPLATE_VIS set;
+template <class, class, class> class _LIBCPP_TEMPLATE_VIS multiset;
+#endif
+
 template <class _Tp, class _Compare, class _Allocator> class __tree;
 template <class _Tp, class _NodePtr, class _DiffType>
     class _LIBCPP_TEMPLATE_VIS __tree_iterator;
@@ -965,7 +971,7 @@ private:
 template<class _Tp, class _Compare>
 #ifndef _LIBCPP_CXX03_LANG
     _LIBCPP_DIAGNOSE_WARNING(!std::__invokable<_Compare const&, _Tp const&, _Tp const&>::value,
-        "the specified comparator type does not provide a const call operator")
+        "the specified comparator type does not provide a viable const call operator")
 #endif
 int __diagnose_non_const_comparator();
 
@@ -1090,8 +1096,8 @@ public:
     __tree(const value_compare& __comp, const allocator_type& __a);
     __tree(const __tree& __t);
     __tree& operator=(const __tree& __t);
-    template <class _InputIterator>
+    template <class _ForwardIterator>
-        void __assign_unique(_InputIterator __first, _InputIterator __last);
+        void __assign_unique(_ForwardIterator __first, _ForwardIterator __last);
     template <class _InputIterator>
         void __assign_multi(_InputIterator __first, _InputIterator __last);
 #ifndef _LIBCPP_CXX03_LANG
@@ -1326,10 +1332,7 @@ public:
 #endif // !_LIBCPP_CXX03_LANG
 
     _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __node_insert_unique(__node_pointer __nd);
+    pair<iterator, bool> __node_assign_unique(const __container_value_type& __v, __node_pointer __dest);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator             __node_insert_unique(const_iterator __p,
-                                              __node_pointer __nd);
 
     _LIBCPP_INLINE_VISIBILITY
     iterator __node_insert_multi(__node_pointer __nd);
@@ -1509,8 +1512,50 @@ private:
     _LIBCPP_INLINE_VISIBILITY
     void __move_assign_alloc(__tree&, false_type) _NOEXCEPT {}
 
-    __node_pointer __detach();
+    struct _DetachedTreeCache {
-    static __node_pointer __detach(__node_pointer);
+      _LIBCPP_INLINE_VISIBILITY
+      explicit _DetachedTreeCache(__tree *__t) _NOEXCEPT : __t_(__t),
+        __cache_root_(__detach_from_tree(__t)) {
+          __advance();
+        }
+
+      _LIBCPP_INLINE_VISIBILITY
+      __node_pointer __get() const _NOEXCEPT {
+        return __cache_elem_;
+      }
+
+      _LIBCPP_INLINE_VISIBILITY
+      void __advance() _NOEXCEPT {
+        __cache_elem_ = __cache_root_;
+        if (__cache_root_) {
+          __cache_root_ = __detach_next(__cache_root_);
+        }
+      }
+
+      _LIBCPP_INLINE_VISIBILITY
+      ~_DetachedTreeCache() {
+        __t_->destroy(__cache_elem_);
+        if (__cache_root_) {
+          while (__cache_root_->__parent_ != nullptr)
+            __cache_root_ = static_cast<__node_pointer>(__cache_root_->__parent_);
+          __t_->destroy(__cache_root_);
+        }
+      }
+
+       _DetachedTreeCache(_DetachedTreeCache const&) = delete;
+       _DetachedTreeCache& operator=(_DetachedTreeCache const&) = delete;
+
+    private:
+      _LIBCPP_INLINE_VISIBILITY
+      static __node_pointer __detach_from_tree(__tree *__t) _NOEXCEPT;
+      _LIBCPP_INLINE_VISIBILITY
+      static __node_pointer __detach_next(__node_pointer) _NOEXCEPT;
+
+      __tree *__t_;
+      __node_pointer __cache_root_;
+      __node_pointer __cache_elem_;
+    };
+
 
     template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
     template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
@@ -1548,13 +1593,13 @@ __tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp,
 // Precondition:  size() != 0
 template <class _Tp, class _Compare, class _Allocator>
 typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
-__tree<_Tp, _Compare, _Allocator>::__detach()
+__tree<_Tp, _Compare, _Allocator>::_DetachedTreeCache::__detach_from_tree(__tree *__t) _NOEXCEPT
 {
-    __node_pointer __cache = static_cast<__node_pointer>(__begin_node());
+    __node_pointer __cache = static_cast<__node_pointer>(__t->__begin_node());
-    __begin_node() = __end_node();
+    __t->__begin_node() = __t->__end_node();
-    __end_node()->__left_->__parent_ = nullptr;
+    __t->__end_node()->__left_->__parent_ = nullptr;
-    __end_node()->__left_ = nullptr;
+    __t->__end_node()->__left_ = nullptr;
-    size() = 0;
+    __t->size() = 0;
     // __cache->__left_ == nullptr
     if (__cache->__right_ != nullptr)
         __cache = static_cast<__node_pointer>(__cache->__right_);
@@ -1569,7 +1614,7 @@ __tree<_Tp, _Compare, _Allocator>::__detach()
 //    This is no longer a red-black tree
 template <class _Tp, class _Compare, class _Allocator>
 typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
-__tree<_Tp, _Compare, _Allocator>::__detach(__node_pointer __cache)
+__tree<_Tp, _Compare, _Allocator>::_DetachedTreeCache::__detach_next(__node_pointer __cache) _NOEXCEPT
 {
     if (__cache->__parent_ == nullptr)
         return nullptr;
@@ -1603,45 +1648,23 @@ __tree<_Tp, _Compare, _Allocator>::operator=(const __tree& __t)
 }
 
 template <class _Tp, class _Compare, class _Allocator>
-template <class _InputIterator>
+template <class _ForwardIterator>
 void
-__tree<_Tp, _Compare, _Allocator>::__assign_unique(_InputIterator __first, _InputIterator __last)
+__tree<_Tp, _Compare, _Allocator>::__assign_unique(_ForwardIterator __first, _ForwardIterator __last)
 {
-    typedef iterator_traits<_InputIterator> _ITraits;
+    typedef iterator_traits<_ForwardIterator> _ITraits;
     typedef typename _ITraits::value_type _ItValueType;
     static_assert((is_same<_ItValueType, __container_value_type>::value),
                   "__assign_unique may only be called with the containers value type");
-
+    static_assert(__is_forward_iterator<_ForwardIterator>::value,
+                  "__assign_unique requires a forward iterator");
     if (size() != 0)
     {
-        __node_pointer __cache = __detach();
+        _DetachedTreeCache __cache(this);
-#ifndef _LIBCPP_NO_EXCEPTIONS
+          for (; __cache.__get() != nullptr && __first != __last; ++__first) {
-        try
+              if (__node_assign_unique(*__first, __cache.__get()).second)
-        {
+                  __cache.__advance();
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (; __cache != nullptr && __first != __last; ++__first)
-            {
-                __cache->__value_ = *__first;
-                __node_pointer __next = __detach(__cache);
-                __node_insert_unique(__cache);
-                __cache = __next;
             }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            while (__cache->__parent_ != nullptr)
-                __cache = static_cast<__node_pointer>(__cache->__parent_);
-            destroy(__cache);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        if (__cache != nullptr)
-        {
-            while (__cache->__parent_ != nullptr)
-                __cache = static_cast<__node_pointer>(__cache->__parent_);
-            destroy(__cache);
-        }
     }
     for (; __first != __last; ++__first)
         __insert_unique(*__first);
@@ -1660,33 +1683,11 @@ __tree<_Tp, _Compare, _Allocator>::__assign_multi(_InputIterator __first, _Input
                   " or the nodes value type");
     if (size() != 0)
     {
-        __node_pointer __cache = __detach();
+        _DetachedTreeCache __cache(this);
-#ifndef _LIBCPP_NO_EXCEPTIONS
+        for (; __cache.__get() && __first != __last; ++__first) {
-        try
+            __cache.__get()->__value_ = *__first;
-        {
+            __node_insert_multi(__cache.__get());
-#endif  // _LIBCPP_NO_EXCEPTIONS
+            __cache.__advance();
-            for (; __cache != nullptr && __first != __last; ++__first)
-            {
-                __cache->__value_ = *__first;
-                __node_pointer __next = __detach(__cache);
-                __node_insert_multi(__cache);
-                __cache = __next;
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            while (__cache->__parent_ != nullptr)
-                __cache = static_cast<__node_pointer>(__cache->__parent_);
-            destroy(__cache);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        if (__cache != nullptr)
-        {
-            while (__cache->__parent_ != nullptr)
-                __cache = static_cast<__node_pointer>(__cache->__parent_);
-            destroy(__cache);
         }
     }
     for (; __first != __last; ++__first)
@@ -1784,33 +1785,11 @@ __tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, false_type)
         const_iterator __e = end();
         if (size() != 0)
         {
-            __node_pointer __cache = __detach();
+            _DetachedTreeCache __cache(this);
-#ifndef _LIBCPP_NO_EXCEPTIONS
+            while (__cache.__get() != nullptr && __t.size() != 0) {
-            try
+              __cache.__get()->__value_ = _VSTD::move(__t.remove(__t.begin())->__value_);
-            {
+              __node_insert_multi(__cache.__get());
-#endif  // _LIBCPP_NO_EXCEPTIONS
+              __cache.__advance();
-                while (__cache != nullptr && __t.size() != 0)
-                {
-                    __cache->__value_ = _VSTD::move(__t.remove(__t.begin())->__value_);
-                    __node_pointer __next = __detach(__cache);
-                    __node_insert_multi(__cache);
-                    __cache = __next;
-                }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-            }
-            catch (...)
-            {
-                while (__cache->__parent_ != nullptr)
-                    __cache = static_cast<__node_pointer>(__cache->__parent_);
-                destroy(__cache);
-                throw;
-            }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            if (__cache != nullptr)
-            {
-                while (__cache->__parent_ != nullptr)
-                    __cache = static_cast<__node_pointer>(__cache->__parent_);
-                destroy(__cache);
             }
         }
         while (__t.size() != 0)
@@ -2319,14 +2298,15 @@ __tree<_Tp, _Compare, _Allocator>::__insert_multi(const_iterator __p, const __co
 
 template <class _Tp, class _Compare, class _Allocator>
 pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__node_insert_unique(__node_pointer __nd)
+__tree<_Tp, _Compare, _Allocator>::__node_assign_unique(const __container_value_type& __v, __node_pointer __nd)
 {
     __parent_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__parent, __nd->__value_);
+    __node_base_pointer& __child = __find_equal(__parent, _NodeTypes::__get_key(__v));
     __node_pointer __r = static_cast<__node_pointer>(__child);
     bool __inserted = false;
     if (__child == nullptr)
     {
+        __nd->__value_ = __v;
         __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
         __r = __nd;
         __inserted = true;
@@ -2334,22 +2314,6 @@ __tree<_Tp, _Compare, _Allocator>::__node_insert_unique(__node_pointer __nd)
     return pair<iterator, bool>(iterator(__r), __inserted);
 }
 
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__node_insert_unique(const_iterator __p,
-                                                        __node_pointer __nd)
-{
-    __parent_pointer __parent;
-    __node_base_pointer __dummy;
-    __node_base_pointer& __child = __find_equal(__p, __parent, __nd->__value_);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    if (__child == nullptr)
-    {
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
-        __r = __nd;
-    }
-    return iterator(__r);
-}
 
 template <class _Tp, class _Compare, class _Allocator>
 typename __tree<_Tp, _Compare, _Allocator>::iterator
@@ -2408,7 +2372,7 @@ __tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(
 
     __insert_node_at(__parent, __child,
                      static_cast<__node_base_pointer>(__ptr));
-    __nh.__release();
+    __nh.__release_ptr();
     return _InsertReturnType{iterator(__ptr), true, _NodeHandle()};
 }
 
@@ -2433,7 +2397,7 @@ __tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(
         __insert_node_at(__parent, __child,
                          static_cast<__node_base_pointer>(__ptr));
         __r = __ptr;
-        __nh.__release();
+        __nh.__release_ptr();
     }
     return iterator(__r);
 }
@@ -2498,7 +2462,7 @@ __tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(_NodeHandle&& __nh
     __node_base_pointer& __child = __find_leaf_high(
         __parent, _NodeTypes::__get_key(__ptr->__value_));
     __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
-    __nh.__release();
+    __nh.__release_ptr();
     return iterator(__ptr);
 }
 
@@ -2517,7 +2481,7 @@ __tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(
     __node_base_pointer& __child = __find_leaf(__hint, __parent,
                                                _NodeTypes::__get_key(__ptr->__value_));
     __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
-    __nh.__release();
+    __nh.__release_ptr();
     return iterator(__ptr);
 }
 

lib/libcxx/include/__tuple

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -54,27 +53,24 @@ template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size<volatile _Tp> : publ
 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size<const volatile _Tp> : public tuple_size<_Tp> {};
 #endif
 
-template <size_t _Ip, class _Tp> class _LIBCPP_TEMPLATE_VIS tuple_element;
+template <size_t _Ip, class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_element;
 
 template <size_t _Ip, class _Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const _Tp>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const _Tp>
 {
-public:
+    typedef _LIBCPP_NODEBUG_TYPE typename add_const<typename tuple_element<_Ip, _Tp>::type>::type type;
-    typedef typename add_const<typename tuple_element<_Ip, _Tp>::type>::type type;
 };
 
 template <size_t _Ip, class _Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, volatile _Tp>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, volatile _Tp>
 {
-public:
+    typedef _LIBCPP_NODEBUG_TYPE typename add_volatile<typename tuple_element<_Ip, _Tp>::type>::type type;
-    typedef typename add_volatile<typename tuple_element<_Ip, _Tp>::type>::type type;
 };
 
 template <size_t _Ip, class _Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const volatile _Tp>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const volatile _Tp>
 {
-public:
+    typedef _LIBCPP_NODEBUG_TYPE typename add_cv<typename tuple_element<_Ip, _Tp>::type>::type type;
-    typedef typename add_cv<typename tuple_element<_Ip, _Tp>::type>::type type;
 };
 
 template <class _Tp> struct __tuple_like : false_type {};
@@ -103,7 +99,7 @@ namespace __detail {
 
 template<typename _Tp, size_t ..._Extra> struct __repeat;
 template<typename _Tp, _Tp ..._Np, size_t ..._Extra> struct __repeat<__integer_sequence<_Tp, _Np...>, _Extra...> {
-  typedef __integer_sequence<_Tp,
+  typedef _LIBCPP_NODEBUG_TYPE __integer_sequence<_Tp,
                            _Np...,
                            sizeof...(_Np) + _Np...,
                            2 * sizeof...(_Np) + _Np...,
@@ -257,7 +253,7 @@ template <class ..._Tp> struct __tuple_types {};
 namespace __indexer_detail {
 
 template <size_t _Idx, class _Tp>
-struct __indexed { using type = _Tp; };
+struct __indexed { using type _LIBCPP_NODEBUG_TYPE = _Tp; };
 
 template <class _Types, class _Indexes> struct __indexer;
 
@@ -272,7 +268,7 @@ __indexed<_Idx, _Tp> __at_index(__indexed<_Idx, _Tp> const&);
 } // namespace __indexer_detail
 
 template <size_t _Idx, class ..._Types>
-using __type_pack_element = typename decltype(
+using __type_pack_element _LIBCPP_NODEBUG_TYPE = typename decltype(
     __indexer_detail::__at_index<_Idx>(
         __indexer_detail::__indexer<
             __tuple_types<_Types...>,
@@ -282,11 +278,10 @@ using __type_pack_element = typename decltype(
 #endif
 
 template <size_t _Ip, class ..._Types>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, __tuple_types<_Types...>>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, __tuple_types<_Types...>>
 {
-public:
     static_assert(_Ip < sizeof...(_Types), "tuple_element index out of range");
-    typedef __type_pack_element<_Ip, _Types...> type;
+    typedef _LIBCPP_NODEBUG_TYPE __type_pack_element<_Ip, _Types...> type;
 };
 
 
@@ -306,34 +301,34 @@ struct __apply_cv_mf<false, false, false> {
 };
 template <>
 struct __apply_cv_mf<false, true, false> {
-  template <class _Tp> using __apply = const _Tp;
+  template <class _Tp> using __apply _LIBCPP_NODEBUG_TYPE  = const _Tp;
 };
 template <>
 struct __apply_cv_mf<false, false, true> {
-  template <class _Tp> using __apply = volatile _Tp;
+  template <class _Tp> using __apply _LIBCPP_NODEBUG_TYPE  = volatile _Tp;
 };
 template <>
 struct __apply_cv_mf<false, true, true> {
-  template <class _Tp> using __apply = const volatile _Tp;
+  template <class _Tp> using __apply _LIBCPP_NODEBUG_TYPE  = const volatile _Tp;
 };
 template <>
 struct __apply_cv_mf<true, false, false> {
-  template <class _Tp> using __apply = _Tp&;
+  template <class _Tp> using __apply _LIBCPP_NODEBUG_TYPE  = _Tp&;
 };
 template <>
 struct __apply_cv_mf<true, true, false> {
-  template <class _Tp> using __apply = const _Tp&;
+  template <class _Tp> using __apply _LIBCPP_NODEBUG_TYPE  = const _Tp&;
 };
 template <>
 struct __apply_cv_mf<true, false, true> {
-  template <class _Tp> using __apply = volatile _Tp&;
+  template <class _Tp> using __apply _LIBCPP_NODEBUG_TYPE  = volatile _Tp&;
 };
 template <>
 struct __apply_cv_mf<true, true, true> {
-  template <class _Tp> using __apply = const volatile _Tp&;
+  template <class _Tp> using __apply _LIBCPP_NODEBUG_TYPE = const volatile _Tp&;
 };
 template <class _Tp, class _RawTp = typename remove_reference<_Tp>::type>
-using __apply_cv_t = __apply_cv_mf<
+using __apply_cv_t _LIBCPP_NODEBUG_TYPE  = __apply_cv_mf<
     is_lvalue_reference<_Tp>::value,
     is_const<_RawTp>::value,
     is_volatile<_RawTp>::value>;
@@ -352,7 +347,7 @@ template <template <class...> class _Tuple, class ..._Types, size_t ..._Idx>
 struct __make_tuple_types_flat<_Tuple<_Types...>, __tuple_indices<_Idx...>> {
   // Specialization for pair, tuple, and __tuple_types
   template <class _Tp, class _ApplyFn = __apply_cv_t<_Tp>>
-  using __apply_quals = __tuple_types<
+  using __apply_quals _LIBCPP_NODEBUG_TYPE = __tuple_types<
       typename _ApplyFn::template __apply<__type_pack_element<_Idx, _Types...>>...
     >;
 };
@@ -380,19 +375,19 @@ struct __make_tuple_types
 
 template <class ..._Types, size_t _Ep>
 struct __make_tuple_types<tuple<_Types...>, _Ep, 0, true> {
-  typedef __tuple_types<_Types...> type;
+  typedef _LIBCPP_NODEBUG_TYPE __tuple_types<_Types...> type;
 };
 
 template <class ..._Types, size_t _Ep>
 struct __make_tuple_types<__tuple_types<_Types...>, _Ep, 0, true> {
-  typedef __tuple_types<_Types...> type;
+  typedef _LIBCPP_NODEBUG_TYPE __tuple_types<_Types...> type;
 };
 
 template <bool ..._Preds>
 struct __all_dummy;
 
 template <bool ..._Pred>
-using __all = is_same<__all_dummy<_Pred...>, __all_dummy<((void)_Pred, true)...>>;
+using __all = _IsSame<__all_dummy<_Pred...>, __all_dummy<((void)_Pred, true)...>>;
 
 struct __tuple_sfinae_base {
   template <template <class, class...> class _Trait,
@@ -457,15 +452,14 @@ struct __tuple_assignable<_Tp, _Up, true, true>
 
 
 template <size_t _Ip, class ..._Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, tuple<_Tp...> >
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, tuple<_Tp...> >
 {
-public:
+    typedef _LIBCPP_NODEBUG_TYPE typename tuple_element<_Ip, __tuple_types<_Tp...> >::type type;
-    typedef typename tuple_element<_Ip, __tuple_types<_Tp...> >::type type;
 };
 
 #if _LIBCPP_STD_VER > 11
 template <size_t _Ip, class ..._Tp>
-using tuple_element_t = typename tuple_element <_Ip, _Tp...>::type;
+using tuple_element_t _LIBCPP_NODEBUG_TYPE  = typename tuple_element <_Ip, _Tp...>::type;
 #endif
 
 template <bool _IsTuple, class _SizeTrait, size_t _Expected>
@@ -477,7 +471,7 @@ struct __tuple_like_with_size_imp<true, _SizeTrait, _Expected>
 
 template <class _Tuple, size_t _ExpectedSize,
           class _RawTuple = typename __uncvref<_Tuple>::type>
-using __tuple_like_with_size = __tuple_like_with_size_imp<
+using __tuple_like_with_size _LIBCPP_NODEBUG_TYPE = __tuple_like_with_size_imp<
                                    __tuple_like<_RawTuple>::value,
                                    tuple_size<_RawTuple>, _ExpectedSize
                               >;

lib/libcxx/include/__undef_macros

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------ __undef_macros ------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is distributed under the University of Illinois Open Source
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/any

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------------ any -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is distributed under the University of Illinois Open Source
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -508,7 +507,7 @@ any::any(_ValueType && __v) : __h(nullptr)
 template <class _ValueType, class ..._Args, class _Tp, class>
 any::any(in_place_type_t<_ValueType>, _Args&&... __args) {
   __any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_Args>(__args)...);
-};
+}
 
 template <class _ValueType, class _Up, class ..._Args, class _Tp, class>
 any::any(in_place_type_t<_ValueType>, initializer_list<_Up> __il, _Args&&... __args) {

lib/libcxx/include/array

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- array -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -92,7 +91,7 @@ template <class T, size_t N >
   void swap(array<T,N>& x, array<T,N>& y) noexcept(noexcept(x.swap(y))); // C++17
 
 template <class T> struct tuple_size;
-template <size_t I, class T> class tuple_element;
+template <size_t I, class T> struct tuple_element;
 template <class T, size_t N> struct tuple_size<array<T, N>>;
 template <size_t I, class T, size_t N> struct tuple_element<I, array<T, N>>;
 template <size_t I, class T, size_t N> T& get(array<T, N>&) noexcept; // constexpr in C++14
@@ -191,17 +190,17 @@ struct _LIBCPP_TEMPLATE_VIS array
 
     // element access:
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reference operator[](size_type __n)             {return __elems_[__n];}
+    reference operator[](size_type __n)             _NOEXCEPT {return __elems_[__n];}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const_reference operator[](size_type __n) const {return __elems_[__n];}
+    const_reference operator[](size_type __n) const _NOEXCEPT {return __elems_[__n];}
 
     _LIBCPP_CONSTEXPR_AFTER_CXX14       reference at(size_type __n);
     _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference at(size_type __n) const;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference front()             {return __elems_[0];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference front()             _NOEXCEPT {return __elems_[0];}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const {return __elems_[0];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const _NOEXCEPT {return __elems_[0];}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference back()              {return __elems_[_Size - 1];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference back()              _NOEXCEPT {return __elems_[_Size - 1];}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  {return __elems_[_Size - 1];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  _NOEXCEPT {return __elems_[_Size - 1];}
 
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     value_type* data() _NOEXCEPT {return __elems_;}
@@ -304,13 +303,13 @@ struct _LIBCPP_TEMPLATE_VIS array<_Tp, 0>
 
     // element access:
     _LIBCPP_INLINE_VISIBILITY
-    reference operator[](size_type) {
+    reference operator[](size_type) _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
       _LIBCPP_UNREACHABLE();
     }
 
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const_reference operator[](size_type) const {
+    const_reference operator[](size_type) const _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
       _LIBCPP_UNREACHABLE();
     }
@@ -328,25 +327,25 @@ struct _LIBCPP_TEMPLATE_VIS array<_Tp, 0>
     }
 
     _LIBCPP_INLINE_VISIBILITY
-    reference front() {
+    reference front() _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
       _LIBCPP_UNREACHABLE();
     }
 
     _LIBCPP_INLINE_VISIBILITY
-    const_reference front() const {
+    const_reference front() const _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
       _LIBCPP_UNREACHABLE();
     }
 
     _LIBCPP_INLINE_VISIBILITY
-    reference back() {
+    reference back() _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
       _LIBCPP_UNREACHABLE();
     }
 
     _LIBCPP_INLINE_VISIBILITY
-    const_reference back() const {
+    const_reference back() const _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
       _LIBCPP_UNREACHABLE();
     }
@@ -434,10 +433,9 @@ struct _LIBCPP_TEMPLATE_VIS tuple_size<array<_Tp, _Size> >
     : public integral_constant<size_t, _Size> {};
 
 template <size_t _Ip, class _Tp, size_t _Size>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
 {
     static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
-public:
     typedef _Tp type;
 };
 

lib/libcxx/include/bit

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------------ bit ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===---------------------------------------------------------------------===//
 
@@ -16,12 +15,42 @@
 
 namespace std {
 
+  template <class T>
+    constexpr bool ispow2(T x) noexcept; // C++20
+  template <class T>
+    constexpr T ceil2(T x);              // C++20
+  template <class T>
+    constexpr T floor2(T x) noexcept;    // C++20
+  template <class T>
+    constexpr T log2p1(T x) noexcept;    // C++20
+
+  // 23.20.2, rotating
+  template<class T>
+    constexpr T rotl(T x, unsigned int s) noexcept; // C++20
+  template<class T>
+    constexpr T rotr(T x, unsigned int s) noexcept; // C++20
+
+  // 23.20.3, counting
+  template<class T>
+    constexpr int countl_zero(T x) noexcept;  // C++20
+  template<class T>
+    constexpr int countl_one(T x) noexcept;   // C++20
+  template<class T>
+    constexpr int countr_zero(T x) noexcept;  // C++20
+  template<class T>
+    constexpr int countr_one(T x) noexcept;   // C++20
+  template<class T>
+    constexpr int popcount(T x) noexcept;     // C++20
+
 } // namespace std
 
 */
 
 #include <__config>
+#include <limits>
+#include <type_traits>
 #include <version>
+#include <__debug>
 
 #if defined(__IBMCPP__)
 #include "support/ibm/support.h"
@@ -34,44 +63,47 @@ namespace std {
 #pragma GCC system_header
 #endif
 
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 #ifndef _LIBCPP_COMPILER_MSVC
 
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __ctz(unsigned __x)           { return __builtin_ctz(__x); }
+int __libcpp_ctz(unsigned __x)           _NOEXCEPT { return __builtin_ctz(__x); }
 
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __ctz(unsigned long __x)      { return __builtin_ctzl(__x); }
+int __libcpp_ctz(unsigned long __x)      _NOEXCEPT { return __builtin_ctzl(__x); }
 
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __ctz(unsigned long long __x) { return __builtin_ctzll(__x); }
+int __libcpp_ctz(unsigned long long __x) _NOEXCEPT { return __builtin_ctzll(__x); }
 
 
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __clz(unsigned __x)           { return __builtin_clz(__x); }
+int __libcpp_clz(unsigned __x)           _NOEXCEPT { return __builtin_clz(__x); }
 
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __clz(unsigned long __x)      { return __builtin_clzl(__x); }
+int __libcpp_clz(unsigned long __x)      _NOEXCEPT { return __builtin_clzl(__x); }
 
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __clz(unsigned long long __x) { return __builtin_clzll(__x); }
+int __libcpp_clz(unsigned long long __x) _NOEXCEPT { return __builtin_clzll(__x); }
 
 
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __popcount(unsigned __x)           { return __builtin_popcount(__x); }
+int __libcpp_popcount(unsigned __x)           _NOEXCEPT { return __builtin_popcount(__x); }
 
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __popcount(unsigned long __x)      { return __builtin_popcountl(__x); }
+int __libcpp_popcount(unsigned long __x)      _NOEXCEPT { return __builtin_popcountl(__x); }
 
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __popcount(unsigned long long __x) { return __builtin_popcountll(__x); }
+int __libcpp_popcount(unsigned long long __x) _NOEXCEPT { return __builtin_popcountll(__x); }
 
 #else  // _LIBCPP_COMPILER_MSVC
 
 // Precondition:  __x != 0
 inline _LIBCPP_INLINE_VISIBILITY
-int __ctz(unsigned __x) {
+int __libcpp_ctz(unsigned __x) {
   static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
   static_assert(sizeof(unsigned long) == 4, "");
   unsigned long __where;
@@ -81,13 +113,13 @@ int __ctz(unsigned __x) {
 }
 
 inline _LIBCPP_INLINE_VISIBILITY
-int __ctz(unsigned long __x) {
+int __libcpp_ctz(unsigned long __x) {
     static_assert(sizeof(unsigned long) == sizeof(unsigned), "");
     return __ctz(static_cast<unsigned>(__x));
 }
 
 inline _LIBCPP_INLINE_VISIBILITY
-int __ctz(unsigned long long __x) {
+int __libcpp_ctz(unsigned long long __x) {
     unsigned long __where;
 #if defined(_LIBCPP_HAS_BITSCAN64)
     (defined(_M_AMD64) || defined(__x86_64__))
@@ -105,7 +137,7 @@ int __ctz(unsigned long long __x) {
 
 // Precondition:  __x != 0
 inline _LIBCPP_INLINE_VISIBILITY
-int __clz(unsigned __x) {
+int __libcpp_clz(unsigned __x) {
   static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
   static_assert(sizeof(unsigned long) == 4, "");
   unsigned long __where;
@@ -115,13 +147,13 @@ int __clz(unsigned __x) {
 }
 
 inline _LIBCPP_INLINE_VISIBILITY
-int __clz(unsigned long __x) {
+int __libcpp_clz(unsigned long __x) {
     static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
-    return __clz(static_cast<unsigned>(__x));
+    return __libcpp_clz(static_cast<unsigned>(__x));
 }
 
 inline _LIBCPP_INLINE_VISIBILITY
-int __clz(unsigned long long __x) {
+int __libcpp_clz(unsigned long long __x) {
   unsigned long __where;
 #if defined(_LIBCPP_HAS_BITSCAN64)
   if (_BitScanReverse64(&__where, __x))
@@ -136,23 +168,298 @@ int __clz(unsigned long long __x) {
   return 64; // Undefined Behavior.
 }
 
-inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned __x) {
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_popcount(unsigned __x) {
   static_assert(sizeof(unsigned) == 4, "");
   return __popcnt(__x);
 }
 
-inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned long __x) {
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_popcount(unsigned long __x) {
   static_assert(sizeof(unsigned long) == 4, "");
   return __popcnt(__x);
 }
 
-inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned long long __x) {
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_popcount(unsigned long long __x) {
   static_assert(sizeof(unsigned long long) == 8, "");
   return __popcnt64(__x);
 }
 
 #endif // _LIBCPP_COMPILER_MSVC
 
+template <class _Tp>
+using __bitop_unsigned_integer _LIBCPP_NODEBUG_TYPE = integral_constant<bool,
+         is_integral<_Tp>::value &&
+         is_unsigned<_Tp>::value &&
+        _IsNotSame<typename remove_cv<_Tp>::type, bool>::value &&
+        _IsNotSame<typename remove_cv<_Tp>::type, signed char>::value &&
+        _IsNotSame<typename remove_cv<_Tp>::type, wchar_t>::value &&
+        _IsNotSame<typename remove_cv<_Tp>::type, char16_t>::value &&
+        _IsNotSame<typename remove_cv<_Tp>::type, char32_t>::value
+    >;
+
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp __rotl(_Tp __t, unsigned int __cnt) _NOEXCEPT
+{
+    static_assert(__bitop_unsigned_integer<_Tp>::value, "__rotl requires unsigned");
+    const unsigned int __dig = numeric_limits<_Tp>::digits;
+    if ((__cnt % __dig) == 0)
+        return __t;
+    return (__t << (__cnt % __dig)) | (__t >> (__dig - (__cnt % __dig)));
+}
+
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp __rotr(_Tp __t, unsigned int __cnt) _NOEXCEPT
+{
+    static_assert(__bitop_unsigned_integer<_Tp>::value, "__rotr requires unsigned");
+    const unsigned int __dig = numeric_limits<_Tp>::digits;
+    if ((__cnt % __dig) == 0)
+        return __t;
+    return (__t >> (__cnt % __dig)) | (__t << (__dig - (__cnt % __dig)));
+}
+
+
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+int __countr_zero(_Tp __t) _NOEXCEPT
+{
+    static_assert(__bitop_unsigned_integer<_Tp>::value, "__countr_zero requires unsigned");
+    if (__t == 0)
+        return numeric_limits<_Tp>::digits;
+
+    if      (sizeof(_Tp) <= sizeof(unsigned int))
+        return __libcpp_ctz(static_cast<unsigned int>(__t));
+    else if (sizeof(_Tp) <= sizeof(unsigned long))
+        return __libcpp_ctz(static_cast<unsigned long>(__t));
+    else if (sizeof(_Tp) <= sizeof(unsigned long long))
+        return __libcpp_ctz(static_cast<unsigned long long>(__t));
+    else
+    {
+        int __ret = 0;
+        int __iter = 0;
+        const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
+        while ((__iter = __libcpp_ctz(static_cast<unsigned long long>(__t))) == __ulldigits)
+        {
+            __ret += __iter;
+            __t >>= __ulldigits;
+        }
+        return __ret + __iter;
+    }
+}
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+int __countl_zero(_Tp __t) _NOEXCEPT
+{
+    static_assert(__bitop_unsigned_integer<_Tp>::value, "__countl_zero requires unsigned");
+    if (__t == 0)
+        return numeric_limits<_Tp>::digits;
+
+    if      (sizeof(_Tp) <= sizeof(unsigned int))
+        return __libcpp_clz(static_cast<unsigned int>(__t))
+              - (numeric_limits<unsigned int>::digits - numeric_limits<_Tp>::digits);
+    else if (sizeof(_Tp) <= sizeof(unsigned long))
+        return __libcpp_clz(static_cast<unsigned long>(__t))
+              - (numeric_limits<unsigned long>::digits - numeric_limits<_Tp>::digits);
+    else if (sizeof(_Tp) <= sizeof(unsigned long long))
+        return __libcpp_clz(static_cast<unsigned long long>(__t))
+              - (numeric_limits<unsigned long long>::digits - numeric_limits<_Tp>::digits);
+    else
+    {
+        int __ret = 0;
+        int __iter = 0;
+        const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
+        while (true) {
+            __t = __rotr(__t, __ulldigits);
+            if ((__iter = __countl_zero(static_cast<unsigned long long>(__t))) != __ulldigits)
+                break;
+            __ret += __iter;
+            }
+        return __ret + __iter;
+    }
+}
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+int __countl_one(_Tp __t) _NOEXCEPT
+{
+    static_assert(__bitop_unsigned_integer<_Tp>::value, "__countl_one requires unsigned");
+    return __t != numeric_limits<_Tp>::max()
+        ? __countl_zero(static_cast<_Tp>(~__t))
+        : numeric_limits<_Tp>::digits;
+}
+
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+int __countr_one(_Tp __t) _NOEXCEPT
+{
+    static_assert(__bitop_unsigned_integer<_Tp>::value, "__countr_one requires unsigned");
+    return __t != numeric_limits<_Tp>::max()
+        ? __countr_zero(static_cast<_Tp>(~__t))
+        : numeric_limits<_Tp>::digits;
+}
+
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+int
+__popcount(_Tp __t) _NOEXCEPT
+{
+    static_assert(__bitop_unsigned_integer<_Tp>::value, "__libcpp_popcount requires unsigned");
+    if      (sizeof(_Tp) <= sizeof(unsigned int))
+        return __libcpp_popcount(static_cast<unsigned int>(__t));
+    else if (sizeof(_Tp) <= sizeof(unsigned long))
+        return __libcpp_popcount(static_cast<unsigned long>(__t));
+    else if (sizeof(_Tp) <= sizeof(unsigned long long))
+        return __libcpp_popcount(static_cast<unsigned long long>(__t));
+    else
+    {
+        int __ret = 0;
+        while (__t != 0)
+        {
+            __ret += __libcpp_popcount(static_cast<unsigned long long>(__t));
+            __t >>= numeric_limits<unsigned long long>::digits;
+        }
+        return __ret;
+    }
+}
+
+
+// integral log base 2
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+unsigned __bit_log2(_Tp __t) _NOEXCEPT
+{
+    static_assert(__bitop_unsigned_integer<_Tp>::value, "__bit_log2 requires unsigned");
+    return std::numeric_limits<_Tp>::digits - 1 - __countl_zero(__t);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+bool __ispow2(_Tp __t) _NOEXCEPT
+{
+    static_assert(__bitop_unsigned_integer<_Tp>::value, "__ispow2 requires unsigned");
+	return __t != 0 && (((__t & (__t - 1)) == 0)); 
+}
+
+
+#if _LIBCPP_STD_VER > 17
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, _Tp>
+rotl(_Tp __t, unsigned int __cnt) noexcept
+{
+    return __rotl(__t, __cnt);
+}
+
+
+// rotr
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, _Tp>
+rotr(_Tp __t, unsigned int __cnt) noexcept
+{
+    return __rotr(__t, __cnt);
+}
+
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, int>
+countl_zero(_Tp __t) noexcept
+{
+    return __countl_zero(__t);
+}
+
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, int>
+countl_one(_Tp __t) noexcept
+{
+    return __countl_one(__t);
+}
+
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, int>
+countr_zero(_Tp __t) noexcept
+{
+	return __countr_zero(__t);
+}
+
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, int>
+countr_one(_Tp __t) noexcept
+{
+    return __countr_one(__t);
+}
+
+
+template<class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, int>
+popcount(_Tp __t) noexcept
+{
+    return __popcount(__t);
+}
+
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, bool>
+ispow2(_Tp __t) noexcept
+{
+    return __ispow2(__t);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, _Tp>
+floor2(_Tp __t) noexcept
+{
+    return __t == 0 ? 0 : _Tp{1} << __bit_log2(__t);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, _Tp>
+ceil2(_Tp __t) noexcept
+{
+    if (__t < 2) return 1;
+    const unsigned __n = numeric_limits<_Tp>::digits - countl_zero((_Tp)(__t - 1u));
+    _LIBCPP_DEBUG_ASSERT(__libcpp_is_constant_evaluated() || __n != numeric_limits<_Tp>::digits, "Bad input to ceil2");
+
+    if constexpr (sizeof(_Tp) >= sizeof(unsigned))
+        return _Tp{1} << __n;
+    else
+    {
+        const unsigned __extra = numeric_limits<unsigned>::digits  - numeric_limits<_Tp>::digits;
+        const unsigned __retVal = 1u << (__n + __extra);
+        return (_Tp) (__retVal >> __extra);
+    }
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<__bitop_unsigned_integer<_Tp>::value, _Tp>
+log2p1(_Tp __t) noexcept
+{
+    return __t == 0 ? 0 : __bit_log2(__t) + 1;
+}
+
+#endif // _LIBCPP_STD_VER > 17
+
 _LIBCPP_END_NAMESPACE_STD
 
+_LIBCPP_POP_MACROS
+
 #endif // _LIBCPP_BIT

lib/libcxx/include/bitset

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- bitset ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -680,7 +679,7 @@ public:
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR bitset() _NOEXCEPT {}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
         bitset(unsigned long long __v) _NOEXCEPT : base(__v) {}
-    template<class _CharT>
+    template<class _CharT, class = _EnableIf<_IsCharLikeType<_CharT>::value> >
         explicit bitset(const _CharT* __str,
                         typename basic_string<_CharT>::size_type __n = basic_string<_CharT>::npos,
                         _CharT __zero = _CharT('0'), _CharT __one = _CharT('1'));
@@ -761,7 +760,7 @@ private:
 };
 
 template <size_t _Size>
-template<class _CharT>
+template<class _CharT, class>
 bitset<_Size>::bitset(const _CharT* __str,
                       typename basic_string<_CharT>::size_type __n,
                       _CharT __zero, _CharT __one)

lib/libcxx/include/cassert

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- cassert -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/ccomplex

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- ccomplex ---------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cctype

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- cctype ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cerrno

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- cerrno ------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cfenv

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- cfenv -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cfloat

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- cfloat -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/charconv

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------------ charconv ------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -97,7 +96,7 @@ _LIBCPP_FUNC_VIS char* __u64toa(uint64_t __value, char* __buffer);
 _LIBCPP_FUNC_VIS char* __u32toa(uint32_t __value, char* __buffer);
 }
 
-#if _LIBCPP_STD_VER > 11
+#ifndef _LIBCPP_CXX03_LANG
 
 enum class _LIBCPP_ENUM_VIS chars_format
 {
@@ -125,7 +124,7 @@ void from_chars(const char*, const char*, bool, int = 10) = delete;
 namespace __itoa
 {
 
-static constexpr uint64_t __pow10_64[] = {
+static _LIBCPP_CONSTEXPR uint64_t __pow10_64[] = {
     UINT64_C(0),
     UINT64_C(10),
     UINT64_C(100),
@@ -148,7 +147,7 @@ static constexpr uint64_t __pow10_64[] = {
     UINT64_C(10000000000000000000),
 };
 
-static constexpr uint32_t __pow10_32[] = {
+static _LIBCPP_CONSTEXPR uint32_t __pow10_32[] = {
     UINT32_C(0),          UINT32_C(10),       UINT32_C(100),
     UINT32_C(1000),       UINT32_C(10000),    UINT32_C(100000),
     UINT32_C(1000000),    UINT32_C(10000000), UINT32_C(100000000),
@@ -173,7 +172,7 @@ struct _LIBCPP_HIDDEN __traits_base
         return __u64toa(__v, __p);
     }
 
-    static _LIBCPP_INLINE_VISIBILITY auto& __pow() { return __pow10_64; }
+    static _LIBCPP_INLINE_VISIBILITY decltype(__pow10_64)& __pow() { return __pow10_64; }
 };
 
 template <typename _Tp>
@@ -195,7 +194,7 @@ struct _LIBCPP_HIDDEN
         return __u32toa(__v, __p);
     }
 
-    static _LIBCPP_INLINE_VISIBILITY auto& __pow() { return __pow10_32; }
+    static _LIBCPP_INLINE_VISIBILITY decltype(__pow10_32)& __pow() { return __pow10_32; }
 };
 
 template <typename _Tp>
@@ -240,7 +239,7 @@ __mul_overflowed(_Tp __a, _Up __b, _Tp& __r)
 template <typename _Tp>
 struct _LIBCPP_HIDDEN __traits : __traits_base<_Tp>
 {
-    static constexpr int digits = numeric_limits<_Tp>::digits10 + 1;
+    static _LIBCPP_CONSTEXPR int digits = numeric_limits<_Tp>::digits10 + 1;
     using __traits_base<_Tp>::__pow;
     using typename __traits_base<_Tp>::type;
 
@@ -286,10 +285,10 @@ __complement(_Tp __x)
 }
 
 template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY auto
+inline _LIBCPP_INLINE_VISIBILITY typename make_unsigned<_Tp>::type
 __to_unsigned(_Tp __x)
 {
-    return static_cast<make_unsigned_t<_Tp>>(__x);
+    return static_cast<typename make_unsigned<_Tp>::type>(__x);
 }
 
 template <typename _Tp>
@@ -315,7 +314,7 @@ __to_chars_itoa(char* __first, char* __last, _Tp __value, false_type)
 
 #if !defined(_LIBCPP_COMPILER_MSVC)
     if (__tx::digits <= __diff || __tx::__width(__value) <= __diff)
-        return {__tx::__convert(__value, __first), {}};
+        return {__tx::__convert(__value, __first), errc(0)};
     else
         return {__last, errc::value_too_large};
 #else
@@ -380,14 +379,14 @@ __to_chars_integral(char* __first, char* __last, _Tp __value, int __base,
     }
 }
 
-template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
+template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
 inline _LIBCPP_INLINE_VISIBILITY to_chars_result
 to_chars(char* __first, char* __last, _Tp __value)
 {
     return __to_chars_itoa(__first, __last, __value, is_signed<_Tp>());
 }
 
-template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
+template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
 inline _LIBCPP_INLINE_VISIBILITY to_chars_result
 to_chars(char* __first, char* __last, _Tp __value, int __base)
 {
@@ -502,7 +501,7 @@ __subject_seq_combinator(_It __first, _It __last, _Tp& __value, _Fn __f,
     return __r;
 }
 
-template <typename _Tp, enable_if_t<is_unsigned<_Tp>::value, int> = 0>
+template <typename _Tp, typename enable_if<is_unsigned<_Tp>::value, int>::type = 0>
 inline _LIBCPP_INLINE_VISIBILITY from_chars_result
 __from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
 {
@@ -528,7 +527,7 @@ __from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
         });
 }
 
-template <typename _Tp, enable_if_t<is_signed<_Tp>::value, int> = 0>
+template <typename _Tp, typename enable_if<is_signed<_Tp>::value, int>::type = 0>
 inline _LIBCPP_INLINE_VISIBILITY from_chars_result
 __from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
 {
@@ -536,7 +535,7 @@ __from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
     return __sign_combinator(__first, __last, __value, __from_chars_atoi<__t>);
 }
 
-template <typename _Tp, enable_if_t<is_unsigned<_Tp>::value, int> = 0>
+template <typename _Tp, typename enable_if<is_unsigned<_Tp>::value, int>::type = 0>
 inline _LIBCPP_INLINE_VISIBILITY from_chars_result
 __from_chars_integral(const char* __first, const char* __last, _Tp& __value,
                       int __base)
@@ -583,7 +582,7 @@ __from_chars_integral(const char* __first, const char* __last, _Tp& __value,
         __base);
 }
 
-template <typename _Tp, enable_if_t<is_signed<_Tp>::value, int> = 0>
+template <typename _Tp, typename enable_if<is_signed<_Tp>::value, int>::type = 0>
 inline _LIBCPP_INLINE_VISIBILITY from_chars_result
 __from_chars_integral(const char* __first, const char* __last, _Tp& __value,
                       int __base)
@@ -593,14 +592,14 @@ __from_chars_integral(const char* __first, const char* __last, _Tp& __value,
                              __from_chars_integral<__t>, __base);
 }
 
-template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
+template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
 inline _LIBCPP_INLINE_VISIBILITY from_chars_result
 from_chars(const char* __first, const char* __last, _Tp& __value)
 {
     return __from_chars_atoi(__first, __last, __value);
 }
 
-template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
+template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
 inline _LIBCPP_INLINE_VISIBILITY from_chars_result
 from_chars(const char* __first, const char* __last, _Tp& __value, int __base)
 {
@@ -608,7 +607,7 @@ from_chars(const char* __first, const char* __last, _Tp& __value, int __base)
     return __from_chars_integral(__first, __last, __value, __base);
 }
 
-#endif  // _LIBCPP_STD_VER > 11
+#endif  // _LIBCPP_CXX03_LANG
 
 _LIBCPP_END_NAMESPACE_STD
 

lib/libcxx/include/chrono

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- chrono ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -1263,34 +1262,15 @@ operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
 
 // Duration /
 
-template <class _Duration, class _Rep, bool = __is_duration<_Rep>::value>
-struct __duration_divide_result
-{
-};
-
-template <class _Duration, class _Rep2,
-    bool = is_convertible<_Rep2,
-                          typename common_type<typename _Duration::rep, _Rep2>::type>::value>
-struct __duration_divide_imp
-{
-};
-
-template <class _Rep1, class _Period, class _Rep2>
-struct __duration_divide_imp<duration<_Rep1, _Period>, _Rep2, true>
-{
-    typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period> type;
-};
-
-template <class _Rep1, class _Period, class _Rep2>
-struct __duration_divide_result<duration<_Rep1, _Period>, _Rep2, false>
-    : __duration_divide_imp<duration<_Rep1, _Period>, _Rep2>
-{
-};
-
 template <class _Rep1, class _Period, class _Rep2>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR
-typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
+typename enable_if
+<
+    !__is_duration<_Rep2>::value &&
+      is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
+    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
+>::type
 operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
 {
     typedef typename common_type<_Rep1, _Rep2>::type _Cr;
@@ -1313,7 +1293,12 @@ operator/(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2
 template <class _Rep1, class _Period, class _Rep2>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR
-typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
+typename enable_if
+<
+    !__is_duration<_Rep2>::value &&
+      is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
+    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
+>::type
 operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
 {
     typedef typename common_type<_Rep1, _Rep2>::type _Cr;
@@ -1605,9 +1590,9 @@ using local_seconds = local_time<seconds>;
 using local_days    = local_time<days>;
 
 
-struct _LIBCPP_TYPE_VIS last_spec { explicit last_spec() = default; };
+struct last_spec { explicit last_spec() = default; };
 
-class _LIBCPP_TYPE_VIS day {
+class day {
 private:
     unsigned char __d;
 public:
@@ -1672,7 +1657,7 @@ inline constexpr day& day::operator-=(const days& __dd) noexcept
 { *this = *this - __dd; return *this; }
 
 
-class _LIBCPP_TYPE_VIS month {
+class month {
 private:
     unsigned char __m;
 public:
@@ -1743,21 +1728,21 @@ inline constexpr month& month::operator-=(const months& __dm) noexcept
 { *this = *this - __dm; return *this; }
 
 
-class _LIBCPP_TYPE_VIS year {
+class year {
 private:
     short __y;
 public:
     year() = default;
     explicit inline constexpr year(int __val) noexcept : __y(static_cast<short>(__val)) {}
 
-    inline constexpr year& operator++()    noexcept { ++__y; return *this; };
+    inline constexpr year& operator++()    noexcept { ++__y; return *this; }
-    inline constexpr year  operator++(int) noexcept { year __tmp = *this; ++(*this); return __tmp; };
+    inline constexpr year  operator++(int) noexcept { year __tmp = *this; ++(*this); return __tmp; }
-    inline constexpr year& operator--()    noexcept { --__y; return *this; };
+    inline constexpr year& operator--()    noexcept { --__y; return *this; }
-    inline constexpr year  operator--(int) noexcept { year __tmp = *this; --(*this); return __tmp; };
+    inline constexpr year  operator--(int) noexcept { year __tmp = *this; --(*this); return __tmp; }
            constexpr year& operator+=(const years& __dy) noexcept;
            constexpr year& operator-=(const years& __dy) noexcept;
     inline constexpr year operator+() const noexcept { return *this; }
-    inline constexpr year operator-() const noexcept { return year{-__y}; };
+    inline constexpr year operator-() const noexcept { return year{-__y}; }
 
     inline constexpr bool is_leap() const noexcept { return __y % 4 == 0 && (__y % 100 != 0 || __y % 400 == 0); }
     explicit inline constexpr operator int() const noexcept { return __y; }
@@ -1817,10 +1802,10 @@ inline constexpr year& year::operator-=(const years& __dy) noexcept
 inline constexpr bool year::ok() const noexcept
 { return static_cast<int>(min()) <= __y && __y <= static_cast<int>(max()); }
 
-class _LIBCPP_TYPE_VIS weekday_indexed;
+class weekday_indexed;
-class _LIBCPP_TYPE_VIS weekday_last;
+class weekday_last;
 
-class _LIBCPP_TYPE_VIS weekday {
+class weekday {
 private:
     unsigned char __wd;
 public:
@@ -1906,7 +1891,7 @@ inline constexpr weekday& weekday::operator-=(const days& __dd) noexcept
 { *this = *this - __dd; return *this; }
 
 
-class _LIBCPP_TYPE_VIS weekday_indexed {
+class weekday_indexed {
 private:
     _VSTD::chrono::weekday __wd;
     unsigned char          __idx;
@@ -1928,7 +1913,7 @@ bool operator!=(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noex
 { return !(__lhs == __rhs); }
 
 
-class _LIBCPP_TYPE_VIS weekday_last {
+class weekday_last {
 private:
     _VSTD::chrono::weekday __wd;
 public:
@@ -1949,7 +1934,7 @@ bool operator!=(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
 inline constexpr
 weekday_indexed weekday::operator[](unsigned __index) const noexcept { return weekday_indexed{*this, __index}; }
 
-inline constexpr 
+inline constexpr
 weekday_last    weekday::operator[](last_spec) const noexcept { return weekday_last{*this}; }
 
 
@@ -1976,7 +1961,7 @@ inline constexpr month November{11};
 inline constexpr month December{12};
 
 
-class _LIBCPP_TYPE_VIS month_day {
+class month_day {
 private:
    chrono::month __m;
    chrono::day   __d;
@@ -2051,7 +2036,7 @@ bool operator>=(const month_day& __lhs, const month_day& __rhs) noexcept
 
 
 
-class _LIBCPP_TYPE_VIS month_day_last {
+class month_day_last {
 private:
     chrono::month __m;
 public:
@@ -2102,7 +2087,7 @@ month_day_last operator/(last_spec, int __rhs) noexcept
 { return month_day_last{month(__rhs)}; }
 
 
-class _LIBCPP_TYPE_VIS month_weekday {
+class month_weekday {
 private:
     chrono::month __m;
     chrono::weekday_indexed __wdi;
@@ -2140,7 +2125,7 @@ month_weekday operator/(const weekday_indexed& __lhs, int __rhs) noexcept
 { return month_weekday{month(__rhs), __lhs}; }
 
 
-class _LIBCPP_TYPE_VIS month_weekday_last {
+class month_weekday_last {
     chrono::month        __m;
     chrono::weekday_last __wdl;
   public:
@@ -2177,7 +2162,7 @@ month_weekday_last operator/(const weekday_last& __lhs, int __rhs) noexcept
 { return month_weekday_last{month(__rhs), __lhs}; }
 
 
-class _LIBCPP_TYPE_VIS year_month {
+class year_month {
     chrono::year  __y;
     chrono::month __m;
 public:
@@ -2251,7 +2236,7 @@ constexpr year_month operator-(const year_month& __lhs, const years& __rhs) noex
 
 class year_month_day_last;
 
-class _LIBCPP_TYPE_VIS year_month_day {
+class year_month_day {
 private:
     chrono::year  __y;
     chrono::month __m;
@@ -2260,7 +2245,7 @@ public:
      year_month_day() = default;
      inline constexpr year_month_day(
             const chrono::year& __yval, const chrono::month& __mval, const chrono::day& __dval) noexcept
-            : __y{__yval}, __m{__mval}, __d{__dval} {}  
+            : __y{__yval}, __m{__mval}, __d{__dval} {}
             constexpr year_month_day(const year_month_day_last& __ymdl) noexcept;
      inline constexpr year_month_day(const sys_days& __sysd) noexcept
             : year_month_day(__from_days(__sysd.time_since_epoch())) {}
@@ -2405,7 +2390,7 @@ inline constexpr year_month_day& year_month_day::operator-=(const months& __dm)
 inline constexpr year_month_day& year_month_day::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
 inline constexpr year_month_day& year_month_day::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
 
-class _LIBCPP_TYPE_VIS year_month_day_last {
+class year_month_day_last {
 private:
     chrono::year           __y;
     chrono::month_day_last __mdl;
@@ -2515,7 +2500,7 @@ inline constexpr year_month_day_last& year_month_day_last::operator+=(const year
 inline constexpr year_month_day_last& year_month_day_last::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
 
 inline constexpr year_month_day::year_month_day(const year_month_day_last& __ymdl) noexcept
-    : __y{__ymdl.year()}, __m{__ymdl.month()}, __d{__ymdl.day()} {}  
+    : __y{__ymdl.year()}, __m{__ymdl.month()}, __d{__ymdl.day()} {}
 
 inline constexpr bool year_month_day::ok() const noexcept
 {
@@ -2523,7 +2508,7 @@ inline constexpr bool year_month_day::ok() const noexcept
     return chrono::day{1} <= __d && __d <= (__y / __m / last).day();
 }
 
-class _LIBCPP_TYPE_VIS year_month_weekday {
+class year_month_weekday {
     chrono::year            __y;
     chrono::month           __m;
     chrono::weekday_indexed __wdi;
@@ -2566,7 +2551,7 @@ year_month_weekday year_month_weekday::__from_days(days __d) noexcept
     const sys_days      __sysd{__d};
     const chrono::weekday __wd = chrono::weekday(__sysd);
     const year_month_day __ymd = year_month_day(__sysd);
-    return year_month_weekday{__ymd.year(), __ymd.month(), 
+    return year_month_weekday{__ymd.year(), __ymd.month(),
                               __wd[(static_cast<unsigned>(__ymd.day())-1)/7+1]};
 }
 
@@ -2637,7 +2622,7 @@ inline constexpr year_month_weekday& year_month_weekday::operator-=(const months
 inline constexpr year_month_weekday& year_month_weekday::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
 inline constexpr year_month_weekday& year_month_weekday::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
 
-class _LIBCPP_TYPE_VIS year_month_weekday_last {
+class year_month_weekday_last {
 private:
     chrono::year         __y;
     chrono::month        __m;
@@ -2658,9 +2643,9 @@ public:
     inline constexpr operator                 sys_days() const noexcept { return   sys_days{__to_days()}; }
     inline explicit constexpr operator      local_days() const noexcept { return local_days{__to_days()}; }
     inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok() && __wdl.ok(); }
-    
+
     constexpr days __to_days() const noexcept;
-    
+
 };
 
 inline constexpr
@@ -2698,7 +2683,7 @@ year_month_weekday_last operator/(const month_weekday_last& __lhs, const year& _
 
 inline constexpr
 year_month_weekday_last operator/(const month_weekday_last& __lhs, int __rhs) noexcept
-{ return year(__rhs) / __lhs; }  
+{ return year(__rhs) / __lhs; }
 
 
 inline constexpr
@@ -2810,7 +2795,7 @@ inline namespace literals
     {
         return chrono::day(static_cast<unsigned>(__d));
     }
- 
+
     constexpr chrono::year operator ""y(unsigned long long __y) noexcept
     {
         return chrono::year(static_cast<int>(__y));
@@ -2842,7 +2827,7 @@ struct _FilesystemClock {
 
   static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
 
-  _LIBCPP_FUNC_VIS static time_point now() noexcept;
+  _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_FUNC_VIS static time_point now() noexcept;
 
   _LIBCPP_INLINE_VISIBILITY
   static time_t to_time_t(const time_point& __t) noexcept {

lib/libcxx/include/cinttypes

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- cinttypes --------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is distributed under the University of Illinois Open Source
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/ciso646

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- ciso646 ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/climits

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- climits ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/clocale

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- clocale ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cmath

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- cmath -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -530,7 +529,7 @@ inline _LIBCPP_INLINE_VISIBILITY long double hypot( long double x, long double y
 
 template <class _A1, class _A2, class _A3>
 inline _LIBCPP_INLINE_VISIBILITY
-typename __lazy_enable_if
+typename _EnableIf
 <
     is_arithmetic<_A1>::value &&
     is_arithmetic<_A2>::value &&
@@ -607,6 +606,32 @@ __libcpp_isfinite_or_builtin(_A1 __lcpp_x) _NOEXCEPT
     return isfinite(__lcpp_x);
 }
 
+#if _LIBCPP_STD_VER > 17
+template <typename _Fp>
+constexpr
+_Fp __lerp(_Fp __a, _Fp __b, _Fp __t) noexcept {
+    if ((__a <= 0 && __b >= 0) || (__a >= 0 && __b <= 0))
+        return __t * __b + (1 - __t) * __a;
+
+    if (__t == 1) return __b;
+    const _Fp __x = __a + __t * (__b - __a);
+    if (__t > 1 == __b > __a)
+    	return __b < __x ? __x : __b;
+    else
+    	return __x < __b ? __x : __b;
+}
+
+constexpr float
+lerp(float __a, float __b, float __t)                   _NOEXCEPT { return __lerp(__a, __b, __t); }
+
+constexpr double
+lerp(double __a, double __b, double __t)                _NOEXCEPT { return __lerp(__a, __b, __t); }
+
+constexpr long double
+lerp(long double __a, long double __b, long double __t) _NOEXCEPT { return __lerp(__a, __b, __t); }
+
+#endif // _LIBCPP_STD_VER > 17
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // _LIBCPP_CMATH

lib/libcxx/include/codecvt

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- codecvt -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/compare

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- compare -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/complex

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- complex ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -1450,10 +1449,10 @@ operator<<(basic_ostream<_CharT, _Traits>& __os, const complex<_Tp>& __x)
     return __os << __s.str();
 }
 
-#if _LIBCPP_STD_VER > 11 
+#if _LIBCPP_STD_VER > 11
 // Literal suffix for complex number literals [complex.literals]
 inline namespace literals
-{ 
+{
   inline namespace complex_literals
   {
     constexpr complex<long double> operator""il(long double __im)

lib/libcxx/include/complex.h

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- complex.h --------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/condition_variable

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------- condition_variable ----------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/csetjmp

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- csetjmp ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/csignal

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- csignal ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cstdarg

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- cstdarg ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cstdbool

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- cstdbool ---------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cstddef

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- cstddef ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cstdint

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- cstdint ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cstdio

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- cstdio ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cstdlib

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- cstdlib ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cstring

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- cstring ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is distributed under the University of Illinois Open Source
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/ctgmath

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- ctgmath -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/ctime

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- ctime -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/ctype.h

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- ctype.h ---------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cwchar

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- cwchar -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/cwctype

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- cwctype ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/deque

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===---------------------------- deque -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -1331,21 +1330,21 @@ public:
 
     // element access:
     _LIBCPP_INLINE_VISIBILITY
-    reference operator[](size_type __i);
+    reference operator[](size_type __i) _NOEXCEPT;
     _LIBCPP_INLINE_VISIBILITY
-    const_reference operator[](size_type __i) const;
+    const_reference operator[](size_type __i) const _NOEXCEPT;
     _LIBCPP_INLINE_VISIBILITY
     reference at(size_type __i);
     _LIBCPP_INLINE_VISIBILITY
     const_reference at(size_type __i) const;
     _LIBCPP_INLINE_VISIBILITY
-    reference front();
+    reference front() _NOEXCEPT;
     _LIBCPP_INLINE_VISIBILITY
-    const_reference front() const;
+    const_reference front() const _NOEXCEPT;
     _LIBCPP_INLINE_VISIBILITY
-    reference back();
+    reference back() _NOEXCEPT;
     _LIBCPP_INLINE_VISIBILITY
-    const_reference back() const;
+    const_reference back() const _NOEXCEPT;
 
     // 23.2.2.3 modifiers:
     void push_front(const value_type& __v);
@@ -1746,7 +1745,7 @@ deque<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
 template <class _Tp, class _Allocator>
 inline
 typename deque<_Tp, _Allocator>::reference
-deque<_Tp, _Allocator>::operator[](size_type __i)
+deque<_Tp, _Allocator>::operator[](size_type __i) _NOEXCEPT
 {
     size_type __p = __base::__start_ + __i;
     return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
@@ -1755,7 +1754,7 @@ deque<_Tp, _Allocator>::operator[](size_type __i)
 template <class _Tp, class _Allocator>
 inline
 typename deque<_Tp, _Allocator>::const_reference
-deque<_Tp, _Allocator>::operator[](size_type __i) const
+deque<_Tp, _Allocator>::operator[](size_type __i) const _NOEXCEPT
 {
     size_type __p = __base::__start_ + __i;
     return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
@@ -1786,7 +1785,7 @@ deque<_Tp, _Allocator>::at(size_type __i) const
 template <class _Tp, class _Allocator>
 inline
 typename deque<_Tp, _Allocator>::reference
-deque<_Tp, _Allocator>::front()
+deque<_Tp, _Allocator>::front() _NOEXCEPT
 {
     return *(*(__base::__map_.begin() + __base::__start_ / __base::__block_size)
                                       + __base::__start_ % __base::__block_size);
@@ -1795,7 +1794,7 @@ deque<_Tp, _Allocator>::front()
 template <class _Tp, class _Allocator>
 inline
 typename deque<_Tp, _Allocator>::const_reference
-deque<_Tp, _Allocator>::front() const
+deque<_Tp, _Allocator>::front() const _NOEXCEPT
 {
     return *(*(__base::__map_.begin() + __base::__start_ / __base::__block_size)
                                       + __base::__start_ % __base::__block_size);
@@ -1804,7 +1803,7 @@ deque<_Tp, _Allocator>::front() const
 template <class _Tp, class _Allocator>
 inline
 typename deque<_Tp, _Allocator>::reference
-deque<_Tp, _Allocator>::back()
+deque<_Tp, _Allocator>::back() _NOEXCEPT
 {
     size_type __p = __base::size() + __base::__start_ - 1;
     return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
@@ -1813,7 +1812,7 @@ deque<_Tp, _Allocator>::back()
 template <class _Tp, class _Allocator>
 inline
 typename deque<_Tp, _Allocator>::const_reference
-deque<_Tp, _Allocator>::back() const
+deque<_Tp, _Allocator>::back() const _NOEXCEPT
 {
     size_type __p = __base::size() + __base::__start_ - 1;
     return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);

lib/libcxx/include/errno.h

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- errno.h -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/exception

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- exception ---------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -83,7 +82,7 @@ template <class E> void rethrow_if_nested(const E& e);
 #include <type_traits>
 #include <version>
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#if defined(_LIBCPP_ABI_VCRUNTIME)
 #include <vcruntime_exception.h>
 #endif
 
@@ -94,7 +93,7 @@ template <class E> void rethrow_if_nested(const E& e);
 namespace std  // purposefully not using versioning namespace
 {
 
-#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 class _LIBCPP_EXCEPTION_ABI exception
 {
 public:
@@ -111,7 +110,7 @@ public:
     virtual ~bad_exception() _NOEXCEPT;
     virtual const char* what() const _NOEXCEPT;
 };
-#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
+#endif // !_LIBCPP_ABI_VCRUNTIME
 
 #if _LIBCPP_STD_VER <= 14 \
     || defined(_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS) \
@@ -261,11 +260,7 @@ struct __throw_with_nested;
 template <class _Tp, class _Up>
 struct __throw_with_nested<_Tp, _Up, true> {
     _LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
-#ifndef _LIBCPP_CXX03_LANG
     __do_throw(_Tp&& __t)
-#else
-    __do_throw (_Tp& __t)
-#endif  // _LIBCPP_CXX03_LANG
     {
         throw __nested<_Up>(_VSTD::forward<_Tp>(__t));
     }
@@ -288,11 +283,7 @@ struct __throw_with_nested<_Tp, _Up, false> {
 template <class _Tp>
 _LIBCPP_NORETURN
 void
-#ifndef _LIBCPP_CXX03_LANG
 throw_with_nested(_Tp&& __t)
-#else
-throw_with_nested (_Tp& __t)
-#endif // _LIBCPP_CXX03_LANG
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     typedef typename decay<_Tp>::type _Up;

lib/libcxx/include/experimental/__config

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- __config ---------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -37,8 +36,14 @@
   namespace chrono { namespace experimental { inline namespace fundamentals_v1 {
 #define _LIBCPP_END_NAMESPACE_CHRONO_LFTS _LIBCPP_END_NAMESPACE_STD } } }
 
+#if defined(_LIBCPP_NO_EXPERIMENTAL_DEPRECATION_WARNING_FILESYSTEM)
+#   define _LIBCPP_DEPRECATED_EXPERIMENTAL_FILESYSTEM /* nothing */
+#else
+#   define _LIBCPP_DEPRECATED_EXPERIMENTAL_FILESYSTEM __attribute__((deprecated("std::experimental::filesystem has now been deprecated in favor of C++17's std::filesystem. Please stop using it and start using std::filesystem. This experimental version will be removed in LLVM 11. You can remove this warning by defining the _LIBCPP_NO_EXPERIMENTAL_DEPRECATION_WARNING_FILESYSTEM macro.")))
+#endif
+
 #define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_FILESYSTEM \
-    _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL namespace filesystem { \
+    _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL namespace filesystem _LIBCPP_DEPRECATED_EXPERIMENTAL_FILESYSTEM { \
     inline namespace v1 {
 
 #define _LIBCPP_END_NAMESPACE_EXPERIMENTAL_FILESYSTEM \

lib/libcxx/include/experimental/__memory

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/algorithm

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- algorithm ---------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/any

@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===------------------------------- any ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_ANY
-#define _LIBCPP_EXPERIMENTAL_ANY
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/any> has been removed. Use <any> instead.")
-#else
-# warning "<experimental/any> has been removed. Use <any> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_ANY

lib/libcxx/include/experimental/chrono

@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- chrono ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_CHRONO
-#define _LIBCPP_EXPERIMENTAL_CHRONO
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/chrono> has been removed. Use <chrono> instead.")
-#else
-# warning "<experimental/chrono> has been removed. Use <chrono> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_CHRONO

lib/libcxx/include/experimental/coroutine

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------- coroutine -----------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is distributed under the University of Illinois Open Source
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -82,7 +81,7 @@ struct __coroutine_traits_sfinae<
 };
 
 template <typename _Ret, typename... _Args>
-struct _LIBCPP_TEMPLATE_VIS coroutine_traits
+struct coroutine_traits
     : public __coroutine_traits_sfinae<_Ret>
 {
 };
@@ -299,7 +298,7 @@ noop_coroutine_handle noop_coroutine() _NOEXCEPT {
 }
 #endif // __has_builtin(__builtin_coro_noop)
 
-struct _LIBCPP_TYPE_VIS suspend_never {
+struct suspend_never {
   _LIBCPP_INLINE_VISIBILITY
   bool await_ready() const _NOEXCEPT { return true; }
   _LIBCPP_INLINE_VISIBILITY
@@ -308,7 +307,7 @@ struct _LIBCPP_TYPE_VIS suspend_never {
   void await_resume() const _NOEXCEPT {}
 };
 
-struct _LIBCPP_TYPE_VIS suspend_always {
+struct suspend_always {
   _LIBCPP_INLINE_VISIBILITY
   bool await_ready() const _NOEXCEPT { return false; }
   _LIBCPP_INLINE_VISIBILITY

lib/libcxx/include/experimental/deque

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- deque ------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/filesystem

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- filesystem -------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 #ifndef _LIBCPP_EXPERIMENTAL_FILESYSTEM

lib/libcxx/include/experimental/forward_list

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- forward_list -----------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/functional

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- functional --------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -110,8 +109,7 @@ _LIBCPP_BEGIN_NAMESPACE_LFTS
 #if _LIBCPP_STD_VER > 11
 // default searcher
 template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
-_LIBCPP_TYPE_VIS
+class _LIBCPP_TYPE_VIS default_searcher {
-class default_searcher {
 public:
     _LIBCPP_INLINE_VISIBILITY
     default_searcher(_ForwardIterator __f, _ForwardIterator __l, 
@@ -209,8 +207,7 @@ public:
 template <class _RandomAccessIterator1, 
           class _Hash = hash<typename iterator_traits<_RandomAccessIterator1>::value_type>, 
           class _BinaryPredicate = equal_to<>>
-_LIBCPP_TYPE_VIS
+class _LIBCPP_TYPE_VIS boyer_moore_searcher {
-class boyer_moore_searcher {
 private:
     typedef typename std::iterator_traits<_RandomAccessIterator1>::difference_type difference_type;
     typedef typename std::iterator_traits<_RandomAccessIterator1>::value_type      value_type;
@@ -361,8 +358,7 @@ make_boyer_moore_searcher( _RandomAccessIterator __f, _RandomAccessIterator __l,
 template <class _RandomAccessIterator1, 
           class _Hash = hash<typename iterator_traits<_RandomAccessIterator1>::value_type>, 
           class _BinaryPredicate = equal_to<>>
-_LIBCPP_TYPE_VIS
+class _LIBCPP_TYPE_VIS boyer_moore_horspool_searcher {
-class boyer_moore_horspool_searcher {
 private:
     typedef typename std::iterator_traits<_RandomAccessIterator1>::difference_type difference_type;
     typedef typename std::iterator_traits<_RandomAccessIterator1>::value_type      value_type;

lib/libcxx/include/experimental/iterator

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------- iterator -------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is distributed under the University of Illinois Open Source
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/list

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- list ------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/map

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------- map ------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/memory_resource

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------ memory_resource -----------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is distributed under the University of Illinois Open Source
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/numeric

@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- numeric ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_NUMERIC
-#define _LIBCPP_EXPERIMENTAL_NUMERIC
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/numeric> has been removed. Use <numeric> instead.")
-#else
-# warning "<experimental/numeric> has been removed. Use <numeric> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_NUMERIC

lib/libcxx/include/experimental/optional

@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- optional ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_OPTIONAL
-#define _LIBCPP_EXPERIMENTAL_OPTIONAL
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/optional> has been removed. Use <optional> instead.")
-#else
-# warning "<experimental/optional> has been removed. Use <optional> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_OPTIONAL

lib/libcxx/include/experimental/propagate_const

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------ propagate_const -----------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/ratio

@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===----------------------------- ratio ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_RATIO
-#define _LIBCPP_EXPERIMENTAL_RATIO
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/ratio> has been removed. Use <ratio> instead.")
-#else
-# warning "<experimental/ratio> has been removed. Use <ratio> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_RATIO

lib/libcxx/include/experimental/regex

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===----------------------------- regex ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/set

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- list ------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/simd

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------------- simd ---------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 #ifndef _LIBCPP_EXPERIMENTAL_SIMD

lib/libcxx/include/experimental/string

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- string ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/string_view

@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===------------------------ string_view ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_STRING_VIEW
-#define _LIBCPP_EXPERIMENTAL_STRING_VIEW
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/string_view> has been removed. Use <string_view> instead.")
-#else
-# warning "<experimental/string_view> has been removed. Use <string_view> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_STRING_VIEW

lib/libcxx/include/experimental/system_error

@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- system_error ------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_SYSTEM_ERROR
-#define _LIBCPP_EXPERIMENTAL_SYSTEM_ERROR
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/system_error> has been removed. Use <system_error> instead.")
-#else
-# warning "<experimental/system_error> has been removed. Use <system_error> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_SYSTEM_ERROR

lib/libcxx/include/experimental/tuple

@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===----------------------------- tuple ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_TUPLE
-#define _LIBCPP_EXPERIMENTAL_TUPLE
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/tuple> has been removed. Use <tuple> instead.")
-#else
-# warning "<experimental/tuple> has been removed. Use <tuple> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_TUPLE

lib/libcxx/include/experimental/type_traits

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- type_traits -------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -73,6 +72,7 @@ inline namespace fundamentals_v1 {
 
 #if _LIBCPP_STD_VER > 11
 
+#include <initializer_list>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -105,11 +105,10 @@ using raw_invocation_type_t = typename raw_invocation_type<_Tp>::type;
 // 3.3.4, Detection idiom
 template <class...> using void_t = void;
 
-struct nonesuch {
+struct nonesuch : private _VSTD::__nat { // make nonesuch "not an aggregate"
-    nonesuch()  = delete;
+  ~nonesuch() = delete;
-    ~nonesuch() = delete;
+  nonesuch      (nonesuch const&) = delete;
-    nonesuch      (nonesuch const&) = delete;
+  void operator=(nonesuch const&) = delete;
-    void operator=(nonesuch const&) = delete;
   };
 
 template <class _Default, class _AlwaysVoid, template <class...> class _Op, class... _Args>

lib/libcxx/include/experimental/unordered_map

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------- unordered_map ------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/unordered_set

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------- unordered_set ------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/utility

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- utility ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/experimental/vector

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- vector ------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 

lib/libcxx/include/ext/__hash

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------- hash_set ------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -17,32 +16,31 @@
 #include <cstring>
 
 namespace __gnu_cxx {
-using namespace std;
 
 template <typename _Tp> struct _LIBCPP_TEMPLATE_VIS hash { };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<const char*>
-    : public unary_function<const char*, size_t>
+ : public std::unary_function<const char*, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(const char *__c) const _NOEXCEPT
     {
-        return __do_string_hash(__c, __c + strlen(__c));
+        return std::__do_string_hash(__c, __c + strlen(__c));
     }
 };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<char *>
-    : public unary_function<char*, size_t>
+ : public std::unary_function<char*, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(char *__c) const _NOEXCEPT
     {
-        return __do_string_hash<const char *>(__c, __c + strlen(__c));
+        return std::__do_string_hash<const char *>(__c, __c + strlen(__c));
     }
 };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<char>
-    : public unary_function<char, size_t>
+ : public std::unary_function<char, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(char __c) const _NOEXCEPT
@@ -52,7 +50,7 @@ template <> struct _LIBCPP_TEMPLATE_VIS hash<char>
 };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<signed char>
-    : public unary_function<signed char, size_t>
+ : public std::unary_function<signed char, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(signed char __c) const _NOEXCEPT
@@ -62,7 +60,7 @@ template <> struct _LIBCPP_TEMPLATE_VIS hash<signed char>
 };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned char>
-    : public unary_function<unsigned char, size_t>
+ : public std::unary_function<unsigned char, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(unsigned char __c) const _NOEXCEPT
@@ -72,7 +70,7 @@ template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned char>
 };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<short>
-    : public unary_function<short, size_t>
+ : public std::unary_function<short, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(short __c) const _NOEXCEPT
@@ -82,7 +80,7 @@ template <> struct _LIBCPP_TEMPLATE_VIS hash<short>
 };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned short>
-    : public unary_function<unsigned short, size_t>
+ : public std::unary_function<unsigned short, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(unsigned short __c) const _NOEXCEPT
@@ -92,7 +90,7 @@ template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned short>
 };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<int>
-    : public unary_function<int, size_t>
+    : public std::unary_function<int, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(int __c) const _NOEXCEPT
@@ -102,7 +100,7 @@ template <> struct _LIBCPP_TEMPLATE_VIS hash<int>
 };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned int>
-    : public unary_function<unsigned int, size_t>
+    : public std::unary_function<unsigned int, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(unsigned int __c) const _NOEXCEPT
@@ -112,7 +110,7 @@ template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned int>
 };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<long>
-    : public unary_function<long, size_t>
+    : public std::unary_function<long, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(long __c) const _NOEXCEPT
@@ -122,7 +120,7 @@ template <> struct _LIBCPP_TEMPLATE_VIS hash<long>
 };
 
 template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned long>
-    : public unary_function<unsigned long, size_t>
+    : public std::unary_function<unsigned long, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     size_t operator()(unsigned long __c) const _NOEXCEPT

lib/libcxx/include/ext/hash_map

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===-------------------------- hash_map ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -220,10 +219,8 @@ template <class Key, class T, class Hash, class Pred, class Alloc>
 
 namespace __gnu_cxx {
 
-using namespace std;
-
 template <class _Tp, class _Hash,
-          bool = is_empty<_Hash>::value && !__libcpp_is_final<_Hash>::value
+          bool = std::is_empty<_Hash>::value && !std::__libcpp_is_final<_Hash>::value
         >
 class __hash_map_hasher
     : private _Hash
@@ -257,7 +254,7 @@ public:
 };
 
 template <class _Tp, class _Pred,
-          bool = is_empty<_Pred>::value && !__libcpp_is_final<_Pred>::value
+          bool = std::is_empty<_Pred>::value && !std::__libcpp_is_final<_Pred>::value
          >
 class __hash_map_equal
     : private _Pred
@@ -308,7 +305,7 @@ template <class _Alloc>
 class __hash_map_node_destructor
 {
     typedef _Alloc                              allocator_type;
-    typedef allocator_traits<allocator_type>    __alloc_traits;
+    typedef std::allocator_traits<allocator_type>    __alloc_traits;
     typedef typename __alloc_traits::value_type::__node_value_type value_type;
 public:
     typedef typename __alloc_traits::pointer    pointer;
@@ -333,7 +330,7 @@ public:
 
 #ifndef _LIBCPP_CXX03_LANG
     _LIBCPP_INLINE_VISIBILITY
-    __hash_map_node_destructor(__hash_node_destructor<allocator_type>&& __x)
+    __hash_map_node_destructor(std::__hash_node_destructor<allocator_type>&& __x)
         : __na_(__x.__na_),
           __first_constructed(__x.__value_constructed),
           __second_constructed(__x.__value_constructed)
@@ -342,7 +339,7 @@ public:
         }
 #else  // _LIBCPP_CXX03_LANG
     _LIBCPP_INLINE_VISIBILITY
-    __hash_map_node_destructor(const __hash_node_destructor<allocator_type>& __x)
+    __hash_map_node_destructor(const std::__hash_node_destructor<allocator_type>& __x)
         : __na_(__x.__na_),
           __first_constructed(__x.__value_constructed),
           __second_constructed(__x.__value_constructed)
@@ -371,11 +368,11 @@ class _LIBCPP_TEMPLATE_VIS __hash_map_iterator
     typedef const typename _HashIterator::value_type::first_type key_type;
     typedef typename _HashIterator::value_type::second_type      mapped_type;
 public:
-    typedef forward_iterator_tag                                 iterator_category;
+    typedef std::forward_iterator_tag                            iterator_category;
-    typedef pair<key_type, mapped_type>                          value_type;
+    typedef std::pair<key_type, mapped_type>                     value_type;
     typedef typename _HashIterator::difference_type              difference_type;
     typedef value_type&                                          reference;
-    typedef typename __rebind_pointer<typename _HashIterator::pointer, value_type>::type
+    typedef typename std::__rebind_pointer<typename _HashIterator::pointer, value_type>::type
         pointer;
 
     _LIBCPP_INLINE_VISIBILITY __hash_map_iterator() {}
@@ -416,11 +413,11 @@ class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator
     typedef const typename _HashIterator::value_type::first_type key_type;
     typedef typename _HashIterator::value_type::second_type      mapped_type;
 public:
-    typedef forward_iterator_tag                                 iterator_category;
+    typedef std::forward_iterator_tag                            iterator_category;
-    typedef pair<key_type, mapped_type>                          value_type;
+    typedef std::pair<key_type, mapped_type>                     value_type;
     typedef typename _HashIterator::difference_type              difference_type;
     typedef const value_type&                                    reference;
-    typedef typename __rebind_pointer<typename _HashIterator::pointer, const value_type>::type
+    typedef typename std::__rebind_pointer<typename _HashIterator::pointer, const value_type>::type
         pointer;
 
     _LIBCPP_INLINE_VISIBILITY __hash_map_const_iterator() {}
@@ -460,8 +457,8 @@ public:
     template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
 };
 
-template <class _Key, class _Tp, class _Hash = hash<_Key>, class _Pred = equal_to<_Key>,
+template <class _Key, class _Tp, class _Hash = hash<_Key>, class _Pred = std::equal_to<_Key>,
-          class _Alloc = allocator<pair<const _Key, _Tp> > >
+          class _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
 class _LIBCPP_TEMPLATE_VIS hash_map
 {
 public:
@@ -472,17 +469,18 @@ public:
     typedef _Hash                                          hasher;
     typedef _Pred                                          key_equal;
     typedef _Alloc                                         allocator_type;
-    typedef pair<const key_type, mapped_type>              value_type;
+    typedef std::pair<const key_type, mapped_type>         value_type;
     typedef value_type&                                    reference;
     typedef const value_type&                              const_reference;
 
 private:
-    typedef pair<key_type, mapped_type>                    __value_type;
+    typedef std::pair<key_type, mapped_type>                    __value_type;
     typedef __hash_map_hasher<__value_type, hasher>   __hasher;
     typedef __hash_map_equal<__value_type, key_equal> __key_equal;
-    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>, __value_type>::type __allocator_type;
+    typedef typename std::__rebind_alloc_helper<
+        std::allocator_traits<allocator_type>, __value_type>::type __allocator_type;
 
-    typedef __hash_table<__value_type, __hasher,
+    typedef std::__hash_table<__value_type, __hasher,
                          __key_equal,  __allocator_type>   __table;
 
     __table __table_;
@@ -493,8 +491,8 @@ private:
     typedef typename __table::__node_allocator             __node_allocator;
     typedef typename __table::__node                       __node;
     typedef __hash_map_node_destructor<__node_allocator>   _Dp;
-    typedef unique_ptr<__node, _Dp>                         __node_holder;
+    typedef std::unique_ptr<__node, _Dp>                   __node_holder;
-    typedef allocator_traits<allocator_type>               __alloc_traits;
+    typedef std::allocator_traits<allocator_type>          __alloc_traits;
 public:
     typedef typename __alloc_traits::pointer         pointer;
     typedef typename __alloc_traits::const_pointer   const_pointer;
@@ -544,7 +542,7 @@ public:
     const_iterator end()    const {return __table_.end();}
 
     _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> insert(const value_type& __x)
+    std::pair<iterator, bool> insert(const value_type& __x)
         {return __table_.__insert_unique(__x);}
     _LIBCPP_INLINE_VISIBILITY
     iterator insert(const_iterator, const value_type& __x) {return insert(__x).first;}
@@ -579,10 +577,10 @@ public:
     _LIBCPP_INLINE_VISIBILITY
     size_type count(const key_type& __k) const {return __table_.__count_unique(__k);}
     _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
+    std::pair<iterator, iterator>             equal_range(const key_type& __k)
         {return __table_.__equal_range_unique(__k);}
     _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
+    std::pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
         {return __table_.__equal_range_unique(__k);}
 
     mapped_type& operator[](const key_type& __k);
@@ -692,7 +690,7 @@ hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](const key_type& __k)
     if (__i != end())
         return __i->second;
     __node_holder __h = __construct_node(__k);
-    pair<iterator, bool> __r = __table_.__node_insert_unique(__h.get());
+    std::pair<iterator, bool> __r = __table_.__node_insert_unique(__h.get());
     __h.release();
     return __r.first->second;
 }
@@ -734,8 +732,8 @@ operator!=(const hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
     return !(__x == __y);
 }
 
-template <class _Key, class _Tp, class _Hash = hash<_Key>, class _Pred = equal_to<_Key>,
+template <class _Key, class _Tp, class _Hash = hash<_Key>, class _Pred = std::equal_to<_Key>,
-          class _Alloc = allocator<pair<const _Key, _Tp> > >
+          class _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
 class _LIBCPP_TEMPLATE_VIS hash_multimap
 {
 public:
@@ -746,17 +744,17 @@ public:
     typedef _Hash                                          hasher;
     typedef _Pred                                          key_equal;
     typedef _Alloc                                         allocator_type;
-    typedef pair<const key_type, mapped_type>              value_type;
+    typedef std::pair<const key_type, mapped_type>         value_type;
     typedef value_type&                                    reference;
     typedef const value_type&                              const_reference;
 
 private:
-    typedef pair<key_type, mapped_type>                    __value_type;
+    typedef std::pair<key_type, mapped_type>               __value_type;
     typedef __hash_map_hasher<__value_type, hasher>   __hasher;
     typedef __hash_map_equal<__value_type, key_equal> __key_equal;
-    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>, __value_type>::type __allocator_type;
+    typedef typename std::__rebind_alloc_helper<std::allocator_traits<allocator_type>, __value_type>::type __allocator_type;
 
-    typedef __hash_table<__value_type, __hasher,
+    typedef std::__hash_table<__value_type, __hasher,
                          __key_equal,  __allocator_type>   __table;
 
     __table __table_;
@@ -765,8 +763,8 @@ private:
     typedef typename __table::__node_allocator             __node_allocator;
     typedef typename __table::__node                       __node;
     typedef __hash_map_node_destructor<__node_allocator>   _Dp;
-    typedef unique_ptr<__node, _Dp>                         __node_holder;
+    typedef std::unique_ptr<__node, _Dp>                         __node_holder;
-    typedef allocator_traits<allocator_type>               __alloc_traits;
+    typedef std::allocator_traits<allocator_type>               __alloc_traits;
 public:
     typedef typename __alloc_traits::pointer         pointer;
     typedef typename __alloc_traits::const_pointer   const_pointer;
@@ -851,10 +849,10 @@ public:
     _LIBCPP_INLINE_VISIBILITY
     size_type count(const key_type& __k) const {return __table_.__count_multi(__k);}
     _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
+    std::pair<iterator, iterator>             equal_range(const key_type& __k)
         {return __table_.__equal_range_multi(__k);}
     _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
+    std::pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
         {return __table_.__equal_range_multi(__k);}
 
     _LIBCPP_INLINE_VISIBILITY
@@ -956,7 +954,7 @@ operator==(const hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
         return false;
     typedef typename hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator
                                                                  const_iterator;
-    typedef pair<const_iterator, const_iterator> _EqRng;
+    typedef std::pair<const_iterator, const_iterator> _EqRng;
     for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;)
     {
         _EqRng __xeq = __x.equal_range(__i->first);

lib/libcxx/include/ext/hash_set

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===------------------------- hash_set ------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ -208,10 +207,9 @@ template <class Value, class Hash, class Pred, class Alloc>
 
 namespace __gnu_cxx {
 
-using namespace std;
 
-template <class _Value, class _Hash = hash<_Value>, class _Pred = equal_to<_Value>,
+template <class _Value, class _Hash = hash<_Value>, class _Pred = std::equal_to<_Value>,
-          class _Alloc = allocator<_Value> >
+          class _Alloc = std::allocator<_Value> >
 class _LIBCPP_TEMPLATE_VIS hash_set
 {
 public:
@@ -225,7 +223,7 @@ public:
     typedef const value_type&                                          const_reference;
 
 private:
-    typedef __hash_table<value_type, hasher, key_equal, allocator_type> __table;
+    typedef std::__hash_table<value_type, hasher, key_equal, allocator_type> __table;
 
     __table __table_;
 
@@ -277,7 +275,7 @@ public:
     const_iterator end()    const {return __table_.end();}
 
     _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> insert(const value_type& __x)
+    std::pair<iterator, bool> insert(const value_type& __x)
         {return __table_.__insert_unique(__x);}
     _LIBCPP_INLINE_VISIBILITY
     iterator insert(const_iterator, const value_type& __x) {return insert(__x).first;}
@@ -310,10 +308,10 @@ public:
     _LIBCPP_INLINE_VISIBILITY
     size_type count(const key_type& __k) const {return __table_.__count_unique(__k);}
     _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
+    std::pair<iterator, iterator>             equal_range(const key_type& __k)
         {return __table_.__equal_range_unique(__k);}
     _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
+    std::pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
         {return __table_.__equal_range_unique(__k);}
 
     _LIBCPP_INLINE_VISIBILITY
@@ -432,8 +430,8 @@ operator!=(const hash_set<_Value, _Hash, _Pred, _Alloc>& __x,
     return !(__x == __y);
 }
 
-template <class _Value, class _Hash = hash<_Value>, class _Pred = equal_to<_Value>,
+template <class _Value, class _Hash = hash<_Value>, class _Pred = std::equal_to<_Value>,
-          class _Alloc = allocator<_Value> >
+          class _Alloc = std::allocator<_Value> >
 class _LIBCPP_TEMPLATE_VIS hash_multiset
 {
 public:
@@ -447,7 +445,7 @@ public:
     typedef const value_type&                                          const_reference;
 
 private:
-    typedef __hash_table<value_type, hasher, key_equal, allocator_type> __table;
+    typedef std::__hash_table<value_type, hasher, key_equal, allocator_type> __table;
 
     __table __table_;
 
@@ -531,10 +529,10 @@ public:
     _LIBCPP_INLINE_VISIBILITY
     size_type count(const key_type& __k) const {return __table_.__count_multi(__k);}
     _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
+    std::pair<iterator, iterator>             equal_range(const key_type& __k)
         {return __table_.__equal_range_multi(__k);}
     _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
+    std::pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
         {return __table_.__equal_range_multi(__k);}
 
     _LIBCPP_INLINE_VISIBILITY
@@ -611,7 +609,7 @@ template <class _InputIterator>
 inline
 void
 hash_multiset<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
-                                                         _InputIterator __last)
+                                                    _InputIterator __last)
 {
     for (; __first != __last; ++__first)
         __table_.__insert_multi(*__first);
@@ -635,7 +633,7 @@ operator==(const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
         return false;
     typedef typename hash_multiset<_Value, _Hash, _Pred, _Alloc>::const_iterator
                                                                  const_iterator;
-    typedef pair<const_iterator, const_iterator> _EqRng;
+    typedef std::pair<const_iterator, const_iterator> _EqRng;
     for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;)
     {
         _EqRng __xeq = __x.equal_range(*__i);

lib/libcxx/include/fenv.h

@@ -0,0 +1,116 @@
+// -*- C++ -*-
+//===---------------------------- math.h ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_FENV_H
+#define _LIBCPP_FENV_H
+
+
+/*
+    fenv.h synopsis
+
+This entire header is C99 / C++0X
+
+Macros:
+
+    FE_DIVBYZERO
+    FE_INEXACT
+    FE_INVALID
+    FE_OVERFLOW
+    FE_UNDERFLOW
+    FE_ALL_EXCEPT
+    FE_DOWNWARD
+    FE_TONEAREST
+    FE_TOWARDZERO
+    FE_UPWARD
+    FE_DFL_ENV
+
+Types:
+
+    fenv_t
+    fexcept_t
+
+int feclearexcept(int excepts);
+int fegetexceptflag(fexcept_t* flagp, int excepts);
+int feraiseexcept(int excepts);
+int fesetexceptflag(const fexcept_t* flagp, int excepts);
+int fetestexcept(int excepts);
+int fegetround();
+int fesetround(int round);
+int fegetenv(fenv_t* envp);
+int feholdexcept(fenv_t* envp);
+int fesetenv(const fenv_t* envp);
+int feupdateenv(const fenv_t* envp);
+
+
+*/
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#include_next <fenv.h>
+
+#ifdef __cplusplus
+
+extern "C++" {
+
+#ifdef feclearexcept
+#undef feclearexcept
+#endif
+
+#ifdef fegetexceptflag
+#undef fegetexceptflag
+#endif
+
+
+#ifdef feraiseexcept
+#undef feraiseexcept
+#endif
+
+#ifdef fesetexceptflag
+#undef fesetexceptflag
+#endif
+
+
+#ifdef fetestexcept
+#undef fetestexcept
+#endif
+
+#ifdef fegetround
+#undef fegetround
+#endif
+
+#ifdef fesetround
+#undef fesetround
+#endif
+
+#ifdef fegetenv
+#undef fegetenv
+#endif
+
+#ifdef feholdexcept
+#undef feholdexcept
+#endif
+
+
+#ifdef fesetenv
+#undef fesetenv
+#endif
+
+#ifdef feupdateenv
+#undef feupdateenv
+#endif
+
+} // extern "C++"
+
+#endif // defined(__cplusplus)
+
+#endif // _LIBCPP_FENV_H

lib/libcxx/include/filesystem

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- filesystem -------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 #ifndef _LIBCPP_FILESYSTEM
@@ -259,6 +258,8 @@ _LIBCPP_PUSH_MACROS
 
 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
 
+_LIBCPP_AVAILABILITY_FILESYSTEM_PUSH
+
 typedef chrono::time_point<_FilesystemClock> file_time_type;
 
 struct _LIBCPP_TYPE_VIS space_info {
@@ -1311,7 +1312,11 @@ inline _LIBCPP_INLINE_VISIBILITY bool operator!=(const path::iterator& __lhs,
   return !(__lhs == __rhs);
 }
 
-class _LIBCPP_EXCEPTION_ABI filesystem_error : public system_error {
+// TODO(ldionne): We need to pop the pragma and push it again after
+//                filesystem_error to work around PR41078.
+_LIBCPP_AVAILABILITY_FILESYSTEM_POP
+
+class _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_EXCEPTION_ABI filesystem_error : public system_error {
 public:
   _LIBCPP_INLINE_VISIBILITY
   filesystem_error(const string& __what, error_code __ec)
@@ -1348,11 +1353,10 @@ public:
     return __storage_->__what_.c_str();
   }
 
-  _LIBCPP_FUNC_VIS
   void __create_what(int __num_paths);
 
 private:
-  struct _Storage {
+  struct _LIBCPP_HIDDEN _Storage {
     _LIBCPP_INLINE_VISIBILITY
     _Storage(const path& __p1, const path& __p2) : __p1_(__p1), __p2_(__p2) {}
 
@@ -1363,16 +1367,16 @@ private:
   shared_ptr<_Storage> __storage_;
 };
 
+_LIBCPP_AVAILABILITY_FILESYSTEM_PUSH
+
 template <class... _Args>
 _LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
 #ifndef _LIBCPP_NO_EXCEPTIONS
-    void
+void __throw_filesystem_error(_Args&&... __args) {
-    __throw_filesystem_error(_Args&&... __args) {
   throw filesystem_error(std::forward<_Args>(__args)...);
 }
 #else
-    void
+void __throw_filesystem_error(_Args&&...) {
-    __throw_filesystem_error(_Args&&...) {
   _VSTD::abort();
 }
 #endif
@@ -1938,7 +1942,7 @@ inline _LIBCPP_INLINE_VISIBILITY path weakly_canonical(path const& __p,
 
 class directory_iterator;
 class recursive_directory_iterator;
-class __dir_stream;
+class _LIBCPP_HIDDEN __dir_stream;
 
 class directory_entry {
   typedef _VSTD_FS::path _Path;
@@ -2601,7 +2605,7 @@ private:
   operator==(const recursive_directory_iterator&,
              const recursive_directory_iterator&) noexcept;
 
-  struct __shared_imp;
+  struct _LIBCPP_HIDDEN __shared_imp;
   shared_ptr<__shared_imp> __imp_;
   bool __rec_;
 }; // class recursive_directory_iterator
@@ -2628,6 +2632,8 @@ end(const recursive_directory_iterator&) noexcept {
   return recursive_directory_iterator();
 }
 
+_LIBCPP_AVAILABILITY_FILESYSTEM_POP
+
 _LIBCPP_END_NAMESPACE_FILESYSTEM
 
 #endif // !_LIBCPP_CXX03_LANG

lib/libcxx/include/float.h

@@ -1,10 +1,9 @@
 // -*- C++ -*-
 //===--------------------------- float.h ----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-//
+// See https://llvm.org/LICENSE.txt for license information.
-// This file is dual licensed under the MIT and the University of Illinois Open
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//