[libc++] Granularize some more of <type_traits>

[ldionne]

I'm fine with this, but I'd like to record that the benefit of splitting small quasi-one-liners into a separate file is limited. I think it's fine for consistency, but if we end up using intrinsics for almost all of the type traits, it may make sense to group them into slightly larger headers, because the boilerplate of a header for 4-5 lines of content is not really worth it.

But like I said, this is consistent with the rest of the code so let's go ahead.

[philnik]

• Try to fix CI

libcxx/include/CMakeLists.txt

set(files
   __type_traits/is_assignable.h
   __type_traits/is_base_of.h
   __type_traits/is_bounded_array.h
   __type_traits/is_callable.h
   __type_traits/is_class.h
   __type_traits/is_compound.h
   __type_traits/is_const.h
   __type_traits/is_constant_evaluated.h
+  __type_traits/is_constructible.h
   __type_traits/is_convertible.h
   __type_traits/is_copy_assignable.h
+  __type_traits/is_copy_constructible.h
   __type_traits/is_core_convertible.h
+  __type_traits/is_default_constructible.h
+  __type_traits/is_destructible.h
   __type_traits/is_empty.h
   __type_traits/is_enum.h
   __type_traits/is_final.h
   __type_traits/is_floating_point.h
   __type_traits/is_function.h
   __type_traits/is_fundamental.h
   __type_traits/is_integral.h
   __type_traits/is_literal_type.h
   __type_traits/is_member_function_pointer.h
   __type_traits/is_member_object_pointer.h
   __type_traits/is_member_pointer.h
   __type_traits/is_move_assignable.h
+  __type_traits/is_move_constructible.h
+  __type_traits/is_nothrow_assignable.h
+  __type_traits/is_nothrow_constructible.h
+  __type_traits/is_nothrow_copy_assignable.h
+  __type_traits/is_nothrow_copy_constructible.h
+  __type_traits/is_nothrow_default_constructible.h
+  __type_traits/is_nothrow_destructible.h
+  __type_traits/is_nothrow_move_assignable.h
+  __type_traits/is_nothrow_move_constructible.h
   __type_traits/is_null_pointer.h
   __type_traits/is_object.h
   __type_traits/is_pod.h
   __type_traits/is_pointer.h
   __type_traits/is_polymorphic.h
   __type_traits/is_reference.h
   __type_traits/is_reference_wrapper.h
   __type_traits/is_referenceable.h
   __type_traits/is_same.h
   __type_traits/is_scalar.h
   __type_traits/is_scoped_enum.h
   __type_traits/is_signed.h
   __type_traits/is_standard_layout.h
   __type_traits/is_trivial.h
+  __type_traits/is_trivially_assignable.h
+  __type_traits/is_trivially_constructible.h
+  __type_traits/is_trivially_copy_assignable.h
+  __type_traits/is_trivially_copy_constructible.h
   __type_traits/is_trivially_copyable.h
+  __type_traits/is_trivially_default_constructible.h
+  __type_traits/is_trivially_destructible.h
+  __type_traits/is_trivially_move_assignable.h
+  __type_traits/is_trivially_move_constructible.h
   __type_traits/is_unbounded_array.h
   __type_traits/is_union.h
   __type_traits/is_unsigned.h
   __type_traits/is_void.h
   __type_traits/is_volatile.h
+  __type_traits/negation.h
   __type_traits/rank.h
   __type_traits/remove_all_extents.h
   __type_traits/remove_const.h
   __type_traits/remove_cv.h
   __type_traits/remove_extent.h
   __type_traits/remove_pointer.h
   __type_traits/remove_reference.h
   __type_traits/remove_volatile.h
   __type_traits/type_identity.h
   __type_traits/underlying_type.h
+  __type_traits/void_t.h
   __undef_macros
   __utility/as_const.h
   __utility/auto_cast.h
   __utility/cmp.h
   __utility/declval.h
   __utility/exchange.h
   __utility/forward.h
   __utility/in_place.h

libcxx/include/__type_traits/is_constructible.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___TYPE_IS_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_IS_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, class ..._Args>
+struct _LIBCPP_TEMPLATE_VIS is_constructible
+    : public integral_constant<bool, __is_constructible(_Tp, _Args...)>
+{ };
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp, class ..._Args>
+inline constexpr bool is_constructible_v = is_constructible<_Tp, _Args...>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_IS_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_copy_constructible.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___TYPE_TRAITS_IS_COPY_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_COPY_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/add_const.h>
+#include <__type_traits/add_lvalue_reference.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_copy_constructible
+    : public is_constructible<_Tp,
+                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_copy_constructible_v = is_copy_constructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_COPY_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_default_constructible.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___TYPE_TRAITS_IS_DEFAULT_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_DEFAULT_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_default_constructible
+    : public is_constructible<_Tp>
+    {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_default_constructible_v = is_default_constructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_DEFAULT_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_destructible.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___TYPE_TRAITS_IS_DESTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_DESTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_function.h>
+#include <__type_traits/is_reference.h>
+#include <__type_traits/remove_all_extents.h>
+#include <__utility/declval.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if __has_keyword(__is_destructible)
+
+template<class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_destructible : _BoolConstant<__is_destructible(_Tp)> { };
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_destructible_v = __is_destructible(_Tp);
+#endif
+
+#else // __has_keyword(__is_destructible)
+
+//  if it's a reference, return true
+//  if it's a function, return false
+//  if it's   void,     return false
+//  if it's an array of unknown bound, return false
+//  Otherwise, return "declval<_Up&>().~_Up()" is well-formed
+//    where _Up is remove_all_extents<_Tp>::type
+
+template <class>
+struct __is_destructible_apply { typedef int type; };
+
+template <typename _Tp>
+struct __is_destructor_wellformed {
+    template <typename _Tp1>
+    static true_type  __test (
+        typename __is_destructible_apply<decltype(declval<_Tp1&>().~_Tp1())>::type
+    );
+
+    template <typename _Tp1>
+    static false_type __test (...);
+
+    static const bool value = decltype(__test<_Tp>(12))::value;
+};
+
+template <class _Tp, bool>
+struct __destructible_imp;
+
+template <class _Tp>
+struct __destructible_imp<_Tp, false>
+   : public integral_constant<bool,
+        __is_destructor_wellformed<typename remove_all_extents<_Tp>::type>::value> {};
+
+template <class _Tp>
+struct __destructible_imp<_Tp, true>
+    : public true_type {};
+
+template <class _Tp, bool>
+struct __destructible_false;
+
+template <class _Tp>
+struct __destructible_false<_Tp, false> : public __destructible_imp<_Tp, is_reference<_Tp>::value> {};
+
+template <class _Tp>
+struct __destructible_false<_Tp, true> : public false_type {};
+
+template <class _Tp>
+struct is_destructible
+    : public __destructible_false<_Tp, is_function<_Tp>::value> {};
+
+template <class _Tp>
+struct is_destructible<_Tp[]>
+    : public false_type {};
+
+template <>
+struct is_destructible<void>
+    : public false_type {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_destructible_v = is_destructible<_Tp>::value;
+#endif
+
+#endif // __has_keyword(__is_destructible)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_DESTRUCTIBLE_H

libcxx/include/__type_traits/is_move_constructible.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___TYPE_TRAITS_IS_MOVE_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_MOVE_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/add_rvalue_reference.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_move_constructible
+    : public is_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
+    {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_move_constructible_v = is_move_constructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_MOVE_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_nothrow_assignable.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___TYPE_TRAITS_IS_NOTHROW_ASSIGNABLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_NOTHROW_ASSIGNABLE_H
+
+#include <__config>
+#include <__type_traits/add_const.h>
+#include <__type_traits/integral_constant.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if __has_keyword(__is_nothrow_assignable)
+
+template <class _Tp, class _Arg>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable
+    : public integral_constant<bool, __is_nothrow_assignable(_Tp, _Arg)> {};
+
+#else
+
+template <bool, class _Tp, class _Arg> struct __libcpp_is_nothrow_assignable;
+
+template <class _Tp, class _Arg>
+struct __libcpp_is_nothrow_assignable<false, _Tp, _Arg>
+    : public false_type
+{
+};
+
+template <class _Tp, class _Arg>
+struct __libcpp_is_nothrow_assignable<true, _Tp, _Arg>
+    : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Arg>()) >
+{
+};
+
+template <class _Tp, class _Arg>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable
+    : public __libcpp_is_nothrow_assignable<is_assignable<_Tp, _Arg>::value, _Tp, _Arg>
+{
+};
+
+#endif // _LIBCPP_HAS_NO_NOEXCEPT
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp, class _Arg>
+inline constexpr bool is_nothrow_assignable_v = is_nothrow_assignable<_Tp, _Arg>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_ASSIGNABLE_H

libcxx/include/__type_traits/is_nothrow_constructible.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___TYPE_TRAITS_IS_NOTHROW_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_NOTHROW_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+#include <__utility/declval.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if __has_keyword(__is_nothrow_constructible)
+
+template <class _Tp, class... _Args>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible
+    : public integral_constant<bool, __is_nothrow_constructible(_Tp, _Args...)> {};
+
+#else
+
+template <bool, bool, class _Tp, class... _Args> struct __libcpp_is_nothrow_constructible;
+
+template <class _Tp, class... _Args>
+struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/false, _Tp, _Args...>
+    : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))>
+{
+};
+
+template <class _Tp>
+void __implicit_conversion_to(_Tp) noexcept { }
+
+template <class _Tp, class _Arg>
+struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/true, _Tp, _Arg>
+    : public integral_constant<bool, noexcept(_VSTD::__implicit_conversion_to<_Tp>(declval<_Arg>()))>
+{
+};
+
+template <class _Tp, bool _IsReference, class... _Args>
+struct __libcpp_is_nothrow_constructible</*is constructible*/false, _IsReference, _Tp, _Args...>
+    : public false_type
+{
+};
+
+template <class _Tp, class... _Args>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible
+    : __libcpp_is_nothrow_constructible<is_constructible<_Tp, _Args...>::value, is_reference<_Tp>::value, _Tp, _Args...>
+{
+};
+
+template <class _Tp, size_t _Ns>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp[_Ns]>
+    : __libcpp_is_nothrow_constructible<is_constructible<_Tp>::value, is_reference<_Tp>::value, _Tp>
+{
+};
+
+#endif // _LIBCPP_HAS_NO_NOEXCEPT
+
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp, class ..._Args>
+inline constexpr bool is_nothrow_constructible_v = is_nothrow_constructible<_Tp, _Args...>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_nothrow_copy_assignable.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___TYPE_TRAITS_IS_NOTHROW_COPY_ASSIGNABLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_NOTHROW_COPY_ASSIGNABLE_H
+
+#include <__config>
+#include <__type_traits/add_const.h>
+#include <__type_traits/add_lvalue_reference.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_nothrow_assignable.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_copy_assignable
+    : public is_nothrow_assignable<typename add_lvalue_reference<_Tp>::type,
+                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_nothrow_copy_assignable_v = is_nothrow_copy_assignable<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_COPY_ASSIGNABLE_H

libcxx/include/__type_traits/is_nothrow_copy_constructible.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___TYPE_TRAITS_IS_NOTHROW_COPY_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_NOTHROW_COPY_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/add_const.h>
+#include <__type_traits/add_lvalue_reference.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_nothrow_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_copy_constructible
+    : public is_nothrow_constructible<_Tp,
+                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_nothrow_copy_constructible_v = is_nothrow_copy_constructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_COPY_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_nothrow_default_constructible.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___TYPE_TRAITS_IS_NOTHROW_DEFAULT_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_NOTHROW_DEFAULT_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_nothrow_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_default_constructible
+    : public is_nothrow_constructible<_Tp>
+    {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_nothrow_default_constructible_v = is_nothrow_default_constructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_DEFAULT_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_nothrow_destructible.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___TYPE_TRAITS_IS_NOTHROW_DESTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_NOTHROW_DESTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/add_const.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_destructible.h>
+#include <__utility/declval.h>
+#include <cstddef>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if !defined(_LIBCPP_CXX03_LANG)
+
+template <bool, class _Tp> struct __libcpp_is_nothrow_destructible;
+
+template <class _Tp>
+struct __libcpp_is_nothrow_destructible<false, _Tp>
+    : public false_type
+{
+};
+
+template <class _Tp>
+struct __libcpp_is_nothrow_destructible<true, _Tp>
+    : public integral_constant<bool, noexcept(declval<_Tp>().~_Tp()) >
+{
+};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible
+    : public __libcpp_is_nothrow_destructible<is_destructible<_Tp>::value, _Tp>
+{
+};
+
+template <class _Tp, size_t _Ns>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp[_Ns]>
+    : public is_nothrow_destructible<_Tp>
+{
+};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp&>
+    : public true_type
+{
+};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp&&>
+    : public true_type
+{
+};
+
+#else
+
+template <class _Tp> struct __libcpp_nothrow_destructor
+    : public integral_constant<bool, is_scalar<_Tp>::value ||
+                                     is_reference<_Tp>::value> {};
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible
+    : public __libcpp_nothrow_destructor<typename remove_all_extents<_Tp>::type> {};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp[]>
+    : public false_type {};
+
+#endif
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_nothrow_destructible_v = is_nothrow_destructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_DESTRUCTIBLE_H

libcxx/include/__type_traits/is_nothrow_move_assignable.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___TYPE_TRAITS_IS_NOTHROW_MOVE_ASSIGNABLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_NOTHROW_MOVE_ASSIGNABLE_H
+
+#include <__config>
+#include <__type_traits/add_lvalue_reference.h>
+#include <__type_traits/add_rvalue_reference.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_nothrow_assignable.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_move_assignable
+    : public is_nothrow_assignable<typename add_lvalue_reference<_Tp>::type,
+                                     typename add_rvalue_reference<_Tp>::type>
+    {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_nothrow_move_assignable_v = is_nothrow_move_assignable<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_MOVE_ASSIGNABLE_H

libcxx/include/__type_traits/is_nothrow_move_constructible.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___TYPE_TRAITS_IS_NOTHROW_MOVE_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_NOTHROW_MOVE_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/add_rvalue_reference.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_nothrow_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_move_constructible
+    : public is_nothrow_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
+    {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_nothrow_move_constructible_v = is_nothrow_move_constructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_MOVE_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_trivially_assignable.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___TYPE_TRAITS_IS_TRIVIALLY_ASSIGNABLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_ASSIGNABLE_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, class _Arg>
+struct is_trivially_assignable
+    : integral_constant<bool, __is_trivially_assignable(_Tp, _Arg)>
+{ };
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp, class _Arg>
+inline constexpr bool is_trivially_assignable_v = is_trivially_assignable<_Tp, _Arg>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_ASSIGNABLE_H

libcxx/include/__type_traits/is_trivially_constructible.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___TYPE_TRAITS_IS_TRIVIALLY_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, class... _Args>
+struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible
+    : integral_constant<bool, __is_trivially_constructible(_Tp, _Args...)>
+{
+};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp, class... _Args>
+inline constexpr bool is_trivially_constructible_v = is_trivially_constructible<_Tp, _Args...>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_trivially_copy_assignable.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___TYPE_TRAITS_IS_TRIVIALLY_COPY_ASSIGNABLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_COPY_ASSIGNABLE_H
+
+#include <__config>
+#include <__type_traits/add_const.h>
+#include <__type_traits/add_lvalue_reference.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_trivially_assignable.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_copy_assignable
+    : public is_trivially_assignable<typename add_lvalue_reference<_Tp>::type,
+                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_trivially_copy_assignable_v = is_trivially_copy_assignable<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_COPY_ASSIGNABLE_H

libcxx/include/__type_traits/is_trivially_copy_constructible.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___TYPE_TRAITS_IS_TRIVIALLY_COPY_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_COPY_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/add_lvalue_reference.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_trivially_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_copy_constructible
+    : public is_trivially_constructible<_Tp, typename add_lvalue_reference<const _Tp>::type>
+    {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_trivially_copy_constructible_v = is_trivially_copy_constructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_COPY_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_trivially_default_constructible.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___TYPE_TRAITS_IS_TRIVIALLY_DEFAULT_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_DEFAULT_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_trivially_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_default_constructible
+    : public is_trivially_constructible<_Tp>
+    {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_trivially_default_constructible_v = is_trivially_default_constructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_DEFAULT_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_trivially_destructible.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___TYPE_TRAITS_IS_TRIVIALLY_DESTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_DESTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if __has_keyword(__is_trivially_destructible)
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible
+    : public integral_constant<bool, __is_trivially_destructible(_Tp)> {};
+
+#elif __has_feature(has_trivial_destructor) || defined(_LIBCPP_COMPILER_GCC)
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible
+    : public integral_constant<bool, is_destructible<_Tp>::value && __has_trivial_destructor(_Tp)> {};
+
+#else
+
+template <class _Tp> struct __libcpp_trivial_destructor
+    : public integral_constant<bool, is_scalar<_Tp>::value ||
+                                     is_reference<_Tp>::value> {};
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible
+    : public __libcpp_trivial_destructor<typename remove_all_extents<_Tp>::type> {};
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible<_Tp[]>
+    : public false_type {};
+
+#endif
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_trivially_destructible_v = is_trivially_destructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_DESTRUCTIBLE_H

libcxx/include/__type_traits/is_trivially_move_assignable.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___TYPE_TRAITS_IS_TRIVIALLY_MOVE_ASSIGNABLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_MOVE_ASSIGNABLE_H
+
+#include <__config>
+#include <__type_traits/add_lvalue_reference.h>
+#include <__type_traits/add_rvalue_reference.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_trivially_assignable.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_move_assignable
+    : public is_trivially_assignable<typename add_lvalue_reference<_Tp>::type,
+                                     typename add_rvalue_reference<_Tp>::type>
+    {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_trivially_move_assignable_v = is_trivially_move_assignable<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_MOVE_ASSIGNABLE_H

libcxx/include/__type_traits/is_trivially_move_constructible.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___TYPE_TRAITS_IS_TRIVIALLY_MOVE_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_MOVE_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/add_rvalue_reference.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_trivially_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_move_constructible
+    : public is_trivially_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
+    {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+inline constexpr bool is_trivially_move_constructible_v = is_trivially_move_constructible<_Tp>::value;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_MOVE_CONSTRUCTIBLE_H

libcxx/include/__type_traits/negation.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___TYPE_TRAITS_NEGATION_H
+#define _LIBCPP___TYPE_TRAITS_NEGATION_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Pred>
+struct _Not : _BoolConstant<!_Pred::value> {};
+
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+struct negation : _Not<_Tp> {};
+template<class _Tp>
+inline constexpr bool negation_v = negation<_Tp>::value;
+#endif // _LIBCPP_STD_VER > 14
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_NEGATION_H

libcxx/include/__type_traits/void_t.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___TYPE_TRAITS_VOID_T_H
+#define _LIBCPP___TYPE_TRAITS_VOID_T_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER > 14
+template <class...> using void_t = void;
+#endif
+
+template <class>
+struct __void_t { typedef void type; };
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_VOID_T_H

libcxx/include/module.modulemap.in

module tuple {
     header "tuple"
     export *
   }
   module type_traits {
     header "type_traits"
     export functional.__functional.unwrap_ref
     export *
 
-    module add_const                        { private header "__type_traits/add_const.h" }
-    module add_cv                           { private header "__type_traits/add_cv.h" }
-    module add_lvalue_reference             { private header "__type_traits/add_lvalue_reference.h" }
-    module add_pointer                      { private header "__type_traits/add_pointer.h" }
-    module add_rvalue_reference             { private header "__type_traits/add_rvalue_reference.h" }
-    module add_volatile                     { private header "__type_traits/add_volatile.h" }
-    module alignment_of                     { private header "__type_traits/alignment_of.h" }
-    module apply_cv                         { private header "__type_traits/apply_cv.h" }
-    module conditional                      { private header "__type_traits/conditional.h" }
-    module conjunction                      { private header "__type_traits/conjunction.h" }
-    module decay                            { private header "__type_traits/decay.h" }
-    module disjunction                      { private header "__type_traits/disjunction.h" }
-    module enable_if                        { private header "__type_traits/enable_if.h" }
-    module extent                           { private header "__type_traits/extent.h" }
-    module has_unique_object_representation { private header "__type_traits/has_unique_object_representation.h" }
-    module has_virtual_destructor           { private header "__type_traits/has_virtual_destructor.h" }
-    module integral_constant                { private header "__type_traits/integral_constant.h" }
-    module is_abstract                      { private header "__type_traits/is_abstract.h" }
-    module is_aggregate                     { private header "__type_traits/is_aggregate.h" }
-    module is_arithmetic                    { private header "__type_traits/is_arithmetic.h" }
-    module is_array                         { private header "__type_traits/is_array.h" }
-    module is_assignable                    { private header "__type_traits/is_assignable.h" }
-    module is_base_of                       { private header "__type_traits/is_base_of.h" }
-    module is_bounded_array                 { private header "__type_traits/is_bounded_array.h" }
-    module is_callable                      { private header "__type_traits/is_callable.h" }
-    module is_class                         { private header "__type_traits/is_class.h" }
-    module is_compound                      { private header "__type_traits/is_compound.h" }
-    module is_const                         { private header "__type_traits/is_const.h" }
-    module is_constant_evaluated            { private header "__type_traits/is_constant_evaluated.h" }
-    module is_convertible                   { private header "__type_traits/is_convertible.h" }
-    module is_copy_assignable               { private header "__type_traits/is_copy_assignable.h" }
-    module is_core_convertible              { private header "__type_traits/is_core_convertible.h" }
-    module is_empty                         { private header "__type_traits/is_empty.h" }
-    module is_enum                          { private header "__type_traits/is_enum.h" }
-    module is_final                         { private header "__type_traits/is_final.h" }
-    module is_floating_point                { private header "__type_traits/is_floating_point.h" }
-    module is_function                      { private header "__type_traits/is_function.h" }
-    module is_fundamental                   { private header "__type_traits/is_fundamental.h" }
-    module is_integral                      { private header "__type_traits/is_integral.h" }
-    module is_literal_type                  { private header "__type_traits/is_literal_type.h" }
-    module is_member_function_pointer       { private header "__type_traits/is_member_function_pointer.h" }
-    module is_member_object_pointer         { private header "__type_traits/is_member_object_pointer.h" }
-    module is_member_pointer                { private header "__type_traits/is_member_pointer.h" }
-    module is_move_assignable               { private header "__type_traits/is_move_assignable.h" }
-    module is_null_pointer                  { private header "__type_traits/is_null_pointer.h" }
-    module is_object                        { private header "__type_traits/is_object.h" }
-    module is_pod                           { private header "__type_traits/is_pod.h" }
-    module is_pointer                       { private header "__type_traits/is_pointer.h" }
-    module is_polymorphic                   { private header "__type_traits/is_polymorphic.h" }
-    module is_reference                     { private header "__type_traits/is_reference.h" }
-    module is_reference_wrapper             { private header "__type_traits/is_reference_wrapper.h" }
-    module is_referenceable                 { private header "__type_traits/is_referenceable.h" }
-    module is_same                          { private header "__type_traits/is_same.h" }
-    module is_scalar                        { private header "__type_traits/is_scalar.h" }
-    module is_scoped_enum                   { private header "__type_traits/is_scoped_enum.h" }
-    module is_signed                        { private header "__type_traits/is_signed.h" }
-    module is_standard_layout               { private header "__type_traits/is_standard_layout.h" }
-    module is_trivial                       { private header "__type_traits/is_trivial.h" }
-    module is_trivially_copyable            { private header "__type_traits/is_trivially_copyable.h" }
-    module is_unbounded_array               { private header "__type_traits/is_unbounded_array.h" }
-    module is_union                         { private header "__type_traits/is_union.h" }
-    module is_unsigned                      { private header "__type_traits/is_unsigned.h" }
-    module is_void                          { private header "__type_traits/is_void.h" }
-    module is_volatile                      { private header "__type_traits/is_volatile.h" }
-    module rank                             { private header "__type_traits/rank.h" }
-    module remove_all_extents               { private header "__type_traits/remove_all_extents.h" }
-    module remove_const                     { private header "__type_traits/remove_const.h" }
-    module remove_cv                        { private header "__type_traits/remove_cv.h" }
-    module remove_extent                    { private header "__type_traits/remove_extent.h" }
-    module remove_pointer                   { private header "__type_traits/remove_pointer.h" }
-    module remove_reference                 { private header "__type_traits/remove_reference.h" }
-    module remove_volatile                  { private header "__type_traits/remove_volatile.h" }
-    module type_identity                    { private header "__type_traits/type_identity.h" }
-    module underlying_type                  { private header "__type_traits/underlying_type.h" }
+    module add_const                          { private header "__type_traits/add_const.h" }
+    module add_cv                             { private header "__type_traits/add_cv.h" }
+    module add_lvalue_reference               { private header "__type_traits/add_lvalue_reference.h" }
+    module add_pointer                        { private header "__type_traits/add_pointer.h" }
+    module add_rvalue_reference               { private header "__type_traits/add_rvalue_reference.h" }
+    module add_volatile                       { private header "__type_traits/add_volatile.h" }
+    module alignment_of                       { private header "__type_traits/alignment_of.h" }
+    module apply_cv                           { private header "__type_traits/apply_cv.h" }
+    module conditional                        { private header "__type_traits/conditional.h" }
+    module conjunction                        { private header "__type_traits/conjunction.h" }
+    module decay                              { private header "__type_traits/decay.h" }
+    module disjunction                        { private header "__type_traits/disjunction.h" }
+    module enable_if                          { private header "__type_traits/enable_if.h" }
+    module extent                             { private header "__type_traits/extent.h" }
+    module has_unique_object_representation   { private header "__type_traits/has_unique_object_representation.h" }
+    module has_virtual_destructor             { private header "__type_traits/has_virtual_destructor.h" }
+    module integral_constant                  { private header "__type_traits/integral_constant.h" }
+    module is_abstract                        { private header "__type_traits/is_abstract.h" }
+    module is_aggregate                       { private header "__type_traits/is_aggregate.h" }
+    module is_arithmetic                      { private header "__type_traits/is_arithmetic.h" }
+    module is_array                           { private header "__type_traits/is_array.h" }
+    module is_assignable                      { private header "__type_traits/is_assignable.h" }
+    module is_base_of                         { private header "__type_traits/is_base_of.h" }
+    module is_bounded_array                   { private header "__type_traits/is_bounded_array.h" }
+    module is_callable                        { private header "__type_traits/is_callable.h" }
+    module is_class                           { private header "__type_traits/is_class.h" }
+    module is_compound                        { private header "__type_traits/is_compound.h" }
+    module is_const                           { private header "__type_traits/is_const.h" }
+    module is_constant_evaluated              { private header "__type_traits/is_constant_evaluated.h" }
+    module is_constructible                   { private header "__type_traits/is_constructible.h" }
+    module is_convertible                     { private header "__type_traits/is_convertible.h" }
+    module is_copy_assignable                 { private header "__type_traits/is_copy_assignable.h" }
+    module is_copy_constructible              { private header "__type_traits/is_copy_constructible.h" }
+    module is_core_convertible                { private header "__type_traits/is_core_convertible.h" }
+    module is_default_constructible           { private header "__type_traits/is_default_constructible.h" }
+    module is_destructible                    { private header "__type_traits/is_destructible.h" }
+    module is_empty                           { private header "__type_traits/is_empty.h" }
+    module is_enum                            { private header "__type_traits/is_enum.h" }
+    module is_final                           { private header "__type_traits/is_final.h" }
+    module is_floating_point                  { private header "__type_traits/is_floating_point.h" }
+    module is_function                        { private header "__type_traits/is_function.h" }
+    module is_fundamental                     { private header "__type_traits/is_fundamental.h" }
+    module is_integral                        { private header "__type_traits/is_integral.h" }
+    module is_literal_type                    { private header "__type_traits/is_literal_type.h" }
+    module is_member_function_pointer         { private header "__type_traits/is_member_function_pointer.h" }
+    module is_member_object_pointer           { private header "__type_traits/is_member_object_pointer.h" }
+    module is_member_pointer                  { private header "__type_traits/is_member_pointer.h" }
+    module is_move_assignable                 { private header "__type_traits/is_move_assignable.h" }
+    module is_move_constructible              { private header "__type_traits/is_move_constructible.h" }
+    module is_nothrow_assignable              { private header "__type_traits/is_nothrow_assignable.h" }
+    module is_nothrow_constructible           { private header "__type_traits/is_nothrow_constructible.h" }
+    module is_nothrow_copy_assignable         { private header "__type_traits/is_nothrow_copy_assignable.h" }
+    module is_nothrow_copy_constructible      { private header "__type_traits/is_nothrow_copy_constructible.h" }
+    module is_nothrow_default_constructible   { private header "__type_traits/is_nothrow_default_constructible.h" }
+    module is_nothrow_destructible            { private header "__type_traits/is_nothrow_destructible.h" }
+    module is_nothrow_move_assignable         { private header "__type_traits/is_nothrow_move_assignable.h" }
+    module is_nothrow_move_constructible      { private header "__type_traits/is_nothrow_move_constructible.h" }
+    module is_null_pointer                    { private header "__type_traits/is_null_pointer.h" }
+    module is_object                          { private header "__type_traits/is_object.h" }
+    module is_pod                             { private header "__type_traits/is_pod.h" }
+    module is_pointer                         { private header "__type_traits/is_pointer.h" }
+    module is_polymorphic                     { private header "__type_traits/is_polymorphic.h" }
+    module is_reference                       { private header "__type_traits/is_reference.h" }
+    module is_reference_wrapper               { private header "__type_traits/is_reference_wrapper.h" }
+    module is_referenceable                   { private header "__type_traits/is_referenceable.h" }
+    module is_same                            { private header "__type_traits/is_same.h" }
+    module is_scalar                          { private header "__type_traits/is_scalar.h" }
+    module is_scoped_enum                     { private header "__type_traits/is_scoped_enum.h" }
+    module is_signed                          { private header "__type_traits/is_signed.h" }
+    module is_standard_layout                 { private header "__type_traits/is_standard_layout.h" }
+    module is_trivial                         { private header "__type_traits/is_trivial.h" }
+    module is_trivially_assignable            { private header "__type_traits/is_trivially_assignable.h" }
+    module is_trivially_constructible         { private header "__type_traits/is_trivially_constructible.h" }
+    module is_trivially_copy_assignable       { private header "__type_traits/is_trivially_copy_assignable.h" }
+    module is_trivially_copy_constructible    { private header "__type_traits/is_trivially_copy_constructible.h" }
+    module is_trivially_copyable              { private header "__type_traits/is_trivially_copyable.h" }
+    module is_trivially_default_constructible { private header "__type_traits/is_trivially_default_constructible.h" }
+    module is_trivially_destructible          { private header "__type_traits/is_trivially_destructible.h" }
+    module is_trivially_move_assignable       { private header "__type_traits/is_trivially_move_assignable.h" }
+    module is_trivially_move_constructible    { private header "__type_traits/is_trivially_move_constructible.h" }
+    module is_unbounded_array                 { private header "__type_traits/is_unbounded_array.h" }
+    module is_union                           { private header "__type_traits/is_union.h" }
+    module is_unsigned                        { private header "__type_traits/is_unsigned.h" }
+    module is_void                            { private header "__type_traits/is_void.h" }
+    module is_volatile                        { private header "__type_traits/is_volatile.h" }
+    module negation                           { private header "__type_traits/negation.h" }
+    module rank                               { private header "__type_traits/rank.h" }
+    module remove_all_extents                 { private header "__type_traits/remove_all_extents.h" }
+    module remove_const                       { private header "__type_traits/remove_const.h" }
+    module remove_cv                          { private header "__type_traits/remove_cv.h" }
+    module remove_extent                      { private header "__type_traits/remove_extent.h" }
+    module remove_pointer                     { private header "__type_traits/remove_pointer.h" }
+    module remove_reference                   { private header "__type_traits/remove_reference.h" }
+    module remove_volatile                    { private header "__type_traits/remove_volatile.h" }
+    module type_identity                      { private header "__type_traits/type_identity.h" }
+    module underlying_type                    { private header "__type_traits/underlying_type.h" }
+    module void_t                             { private header "__type_traits/void_t.h" }
   }
   module typeindex {
     header "typeindex"
     export *
   }
   module typeinfo {
     header "typeinfo"
     export *

libcxx/include/type_traits

 #include <__type_traits/is_assignable.h>
 #include <__type_traits/is_base_of.h>
 #include <__type_traits/is_bounded_array.h>
 #include <__type_traits/is_callable.h>
 #include <__type_traits/is_class.h>
 #include <__type_traits/is_compound.h>
 #include <__type_traits/is_const.h>
 #include <__type_traits/is_constant_evaluated.h>
+#include <__type_traits/is_constructible.h>
 #include <__type_traits/is_convertible.h>
 #include <__type_traits/is_copy_assignable.h>
+#include <__type_traits/is_copy_constructible.h>
+#include <__type_traits/is_default_constructible.h>
+#include <__type_traits/is_destructible.h>
 #include <__type_traits/is_empty.h>
 #include <__type_traits/is_enum.h>
 #include <__type_traits/is_final.h>
 #include <__type_traits/is_floating_point.h>
 #include <__type_traits/is_function.h>
 #include <__type_traits/is_fundamental.h>
 #include <__type_traits/is_integral.h>
 #include <__type_traits/is_literal_type.h>
 #include <__type_traits/is_member_function_pointer.h>
 #include <__type_traits/is_member_object_pointer.h>
 #include <__type_traits/is_member_pointer.h>
 #include <__type_traits/is_move_assignable.h>
+#include <__type_traits/is_move_constructible.h>
+#include <__type_traits/is_nothrow_assignable.h>
+#include <__type_traits/is_nothrow_constructible.h>
+#include <__type_traits/is_nothrow_copy_assignable.h>
+#include <__type_traits/is_nothrow_copy_constructible.h>
+#include <__type_traits/is_nothrow_default_constructible.h>
+#include <__type_traits/is_nothrow_destructible.h>
+#include <__type_traits/is_nothrow_move_assignable.h>
+#include <__type_traits/is_nothrow_move_constructible.h>
 #include <__type_traits/is_null_pointer.h>
 #include <__type_traits/is_object.h>
 #include <__type_traits/is_pod.h>
 #include <__type_traits/is_pointer.h>
 #include <__type_traits/is_polymorphic.h>
 #include <__type_traits/is_reference.h>
 #include <__type_traits/is_reference_wrapper.h>
 #include <__type_traits/is_referenceable.h>
 #include <__type_traits/is_same.h>
 #include <__type_traits/is_scalar.h>
 #include <__type_traits/is_scoped_enum.h>
 #include <__type_traits/is_signed.h>
 #include <__type_traits/is_standard_layout.h>
 #include <__type_traits/is_trivial.h>
+#include <__type_traits/is_trivially_assignable.h>
+#include <__type_traits/is_trivially_constructible.h>
+#include <__type_traits/is_trivially_copy_assignable.h>
+#include <__type_traits/is_trivially_copy_constructible.h>
 #include <__type_traits/is_trivially_copyable.h>
+#include <__type_traits/is_trivially_default_constructible.h>
+#include <__type_traits/is_trivially_destructible.h>
+#include <__type_traits/is_trivially_move_assignable.h>
+#include <__type_traits/is_trivially_move_constructible.h>
 #include <__type_traits/is_unbounded_array.h>
 #include <__type_traits/is_union.h>
 #include <__type_traits/is_unsigned.h>
 #include <__type_traits/is_void.h>
 #include <__type_traits/is_volatile.h>
+#include <__type_traits/negation.h>
 #include <__type_traits/rank.h>
 #include <__type_traits/remove_all_extents.h>
 #include <__type_traits/remove_const.h>
 #include <__type_traits/remove_cv.h>
 #include <__type_traits/remove_extent.h>
 #include <__type_traits/remove_pointer.h>
 #include <__type_traits/remove_reference.h>
 #include <__type_traits/remove_volatile.h>
 #include <__type_traits/type_identity.h>
 #include <__type_traits/underlying_type.h>
+#include <__type_traits/void_t.h>
 #include <__utility/declval.h>
 #include <cstddef>
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
struct _MetaBase<false> {
   using _SelectApplyImpl _LIBCPP_NODEBUG = _SecondFn<_Args...>;
   template <class _Result, class ...>
   using _OrImpl _LIBCPP_NODEBUG = _Result;
 };
 template <bool _Cond, class _IfRes, class _ElseRes>
 using _If _LIBCPP_NODEBUG = typename _MetaBase<_Cond>::template _SelectImpl<_IfRes, _ElseRes>;
 template <class ..._Rest>
 using _Or _LIBCPP_NODEBUG = typename _MetaBase< sizeof...(_Rest) != 0 >::template _OrImpl<false_type, _Rest...>;
-template <class _Pred>
-struct _Not : _BoolConstant<!_Pred::value> {};
 template <class ..._Args>
 using _FirstType _LIBCPP_NODEBUG = typename _MetaBase<(sizeof...(_Args) >= 1)>::template _FirstImpl<_Args...>;
 template <class ..._Args>
 using _SecondType _LIBCPP_NODEBUG = typename _MetaBase<(sizeof...(_Args) >= 2)>::template _SecondImpl<_Args...>;
 
 template <class ...> using __expand_to_true = true_type;
 template <class ..._Pred>
 __expand_to_true<__enable_if_t<_Pred::value>...> __and_helper(int);

 template <template <class...> class _Templ, class ..._Args, class = _Templ<_Args...> >
 true_type __sfinae_test_impl(int);
 template <template <class...> class, class ...>
 false_type __sfinae_test_impl(...);
 
 template <template <class ...> class _Templ, class ..._Args>
 using _IsValidExpansion _LIBCPP_NODEBUG = decltype(__sfinae_test_impl<_Templ, _Args...>(0));
 
-template <class>
-struct __void_t { typedef void type; };
-
 template <class _Tp, bool>
 struct _LIBCPP_TEMPLATE_VIS __dependent_type : public _Tp {};
 
 // is_same
 
 template <class _Tp>
 using __test_for_primary_template = __enable_if_t<
     _IsSame<_Tp, typename _Tp::__primary_template>::value

 #ifndef _LIBCPP_CXX03_LANG
 template <class _Tp>
 _LIBCPP_HIDE_FROM_ABI constexpr
 typename make_unsigned<_Tp>::type __to_unsigned_like(_Tp __x) noexcept {
     return static_cast<typename make_unsigned<_Tp>::type>(__x);
 }
 #endif
 
-#if _LIBCPP_STD_VER > 14
-template <class...> using void_t = void;
-#endif
-
 #if _LIBCPP_STD_VER > 17
 // Let COND_RES(X, Y) be:
 template <class _Tp, class _Up>
 using __cond_type = decltype(false ? declval<_Tp>() : declval<_Up>());
 
 template <class _Tp, class _Up, class = void>
 struct __common_type3 {};
 
struct common_reference<_Tp, _Up, _Vp, _Rest...>
     : common_reference<common_reference_t<_Tp, _Up>, _Vp, _Rest...>
 {};
 
 // bullet 5 - Otherwise, there shall be no member `type`.
 template <class...> struct common_reference {};
 
 #endif // _LIBCPP_STD_VER > 17
 
-// is_destructible
-
-#if __has_keyword(__is_destructible)
-
-template<class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_destructible : _BoolConstant<__is_destructible(_Tp)> { };
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_destructible_v = __is_destructible(_Tp);
-#endif
-
-#else // __has_keyword(__is_destructible)
-
-//  if it's a reference, return true
-//  if it's a function, return false
-//  if it's   void,     return false
-//  if it's an array of unknown bound, return false
-//  Otherwise, return "declval<_Up&>().~_Up()" is well-formed
-//    where _Up is remove_all_extents<_Tp>::type
-
-template <class>
-struct __is_destructible_apply { typedef int type; };
-
-template <typename _Tp>
-struct __is_destructor_wellformed {
-    template <typename _Tp1>
-    static true_type  __test (
-        typename __is_destructible_apply<decltype(declval<_Tp1&>().~_Tp1())>::type
-    );
-
-    template <typename _Tp1>
-    static false_type __test (...);
-
-    static const bool value = decltype(__test<_Tp>(12))::value;
-};
-
-template <class _Tp, bool>
-struct __destructible_imp;
-
-template <class _Tp>
-struct __destructible_imp<_Tp, false>
-   : public integral_constant<bool,
-        __is_destructor_wellformed<typename remove_all_extents<_Tp>::type>::value> {};
-
-template <class _Tp>
-struct __destructible_imp<_Tp, true>
-    : public true_type {};
-
-template <class _Tp, bool>
-struct __destructible_false;
-
-template <class _Tp>
-struct __destructible_false<_Tp, false> : public __destructible_imp<_Tp, is_reference<_Tp>::value> {};
-
-template <class _Tp>
-struct __destructible_false<_Tp, true> : public false_type {};
-
-template <class _Tp>
-struct is_destructible
-    : public __destructible_false<_Tp, is_function<_Tp>::value> {};
-
-template <class _Tp>
-struct is_destructible<_Tp[]>
-    : public false_type {};
-
-template <>
-struct is_destructible<void>
-    : public false_type {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_destructible_v = is_destructible<_Tp>::value;
-#endif
-
-#endif // __has_keyword(__is_destructible)
-
-// template <class T, class... Args> struct is_constructible;
-
-template <class _Tp, class ..._Args>
-struct _LIBCPP_TEMPLATE_VIS is_constructible
-    : public integral_constant<bool, __is_constructible(_Tp, _Args...)>
-{ };
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp, class ..._Args>
-inline constexpr bool is_constructible_v = is_constructible<_Tp, _Args...>::value;
-#endif
-
-// is_default_constructible
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_default_constructible
-    : public is_constructible<_Tp>
-    {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_default_constructible_v = is_default_constructible<_Tp>::value;
-#endif
-
 #ifndef _LIBCPP_CXX03_LANG
 // First of all, we can't implement this check in C++03 mode because the {}
 // default initialization syntax isn't valid.
 // Second, we implement the trait in a funny manner with two defaulted template
 // arguments to workaround Clang's PR43454.
 template <class _Tp>
 void __test_implicit_default_constructible(_Tp);
 
 template <class _Tp, class = void, class = typename is_default_constructible<_Tp>::type>
 struct __is_implicitly_default_constructible
     : false_type
 { };
 
 template <class _Tp>
 struct __is_implicitly_default_constructible<_Tp, decltype(__test_implicit_default_constructible<_Tp const&>({})), true_type>
     : true_type
 { };
 
 template <class _Tp>
 struct __is_implicitly_default_constructible<_Tp, decltype(__test_implicit_default_constructible<_Tp const&>({})), false_type>
     : false_type
 { };
 #endif // !C++03
 
-// is_copy_constructible
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_copy_constructible
-    : public is_constructible<_Tp,
-                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_copy_constructible_v = is_copy_constructible<_Tp>::value;
-#endif
-
-// is_move_constructible
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_move_constructible
-    : public is_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
-    {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_move_constructible_v = is_move_constructible<_Tp>::value;
-#endif
-
-// is_trivially_constructible
-
-template <class _Tp, class... _Args>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible
-    : integral_constant<bool, __is_trivially_constructible(_Tp, _Args...)>
-{
-};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp, class... _Args>
-inline constexpr bool is_trivially_constructible_v = is_trivially_constructible<_Tp, _Args...>::value;
-#endif
-
-// is_trivially_default_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_default_constructible
-    : public is_trivially_constructible<_Tp>
-    {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_trivially_default_constructible_v = is_trivially_default_constructible<_Tp>::value;
-#endif
-
-// is_trivially_copy_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_copy_constructible
-    : public is_trivially_constructible<_Tp, typename add_lvalue_reference<const _Tp>::type>
-    {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_trivially_copy_constructible_v = is_trivially_copy_constructible<_Tp>::value;
-#endif
-
-// is_trivially_move_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_move_constructible
-    : public is_trivially_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
-    {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_trivially_move_constructible_v = is_trivially_move_constructible<_Tp>::value;
-#endif
-
-// is_trivially_assignable
-
-template <class _Tp, class _Arg>
-struct is_trivially_assignable
-    : integral_constant<bool, __is_trivially_assignable(_Tp, _Arg)>
-{ };
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp, class _Arg>
-inline constexpr bool is_trivially_assignable_v = is_trivially_assignable<_Tp, _Arg>::value;
-#endif
-
-// is_trivially_copy_assignable
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_copy_assignable
-    : public is_trivially_assignable<typename add_lvalue_reference<_Tp>::type,
-                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_trivially_copy_assignable_v = is_trivially_copy_assignable<_Tp>::value;
-#endif
-
-// is_trivially_move_assignable
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_move_assignable
-    : public is_trivially_assignable<typename add_lvalue_reference<_Tp>::type,
-                                     typename add_rvalue_reference<_Tp>::type>
-    {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_trivially_move_assignable_v = is_trivially_move_assignable<_Tp>::value;
-#endif
-
-// is_trivially_destructible
-
-#if __has_keyword(__is_trivially_destructible)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible
-    : public integral_constant<bool, __is_trivially_destructible(_Tp)> {};
-
-#elif __has_feature(has_trivial_destructor) || defined(_LIBCPP_COMPILER_GCC)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible
-    : public integral_constant<bool, is_destructible<_Tp>::value && __has_trivial_destructor(_Tp)> {};
-
-#else
-
-template <class _Tp> struct __libcpp_trivial_destructor
-    : public integral_constant<bool, is_scalar<_Tp>::value ||
-                                     is_reference<_Tp>::value> {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible
-    : public __libcpp_trivial_destructor<typename remove_all_extents<_Tp>::type> {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible<_Tp[]>
-    : public false_type {};
-
-#endif
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_trivially_destructible_v = is_trivially_destructible<_Tp>::value;
-#endif
-
-// is_nothrow_constructible
-
-#if __has_keyword(__is_nothrow_constructible)
-
-template <class _Tp, class... _Args>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible
-    : public integral_constant<bool, __is_nothrow_constructible(_Tp, _Args...)> {};
-
-#else
-
-template <bool, bool, class _Tp, class... _Args> struct __libcpp_is_nothrow_constructible;
-
-template <class _Tp, class... _Args>
-struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/false, _Tp, _Args...>
-    : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))>
-{
-};
-
-template <class _Tp>
-void __implicit_conversion_to(_Tp) noexcept { }
-
-template <class _Tp, class _Arg>
-struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/true, _Tp, _Arg>
-    : public integral_constant<bool, noexcept(_VSTD::__implicit_conversion_to<_Tp>(declval<_Arg>()))>
-{
-};
-
-template <class _Tp, bool _IsReference, class... _Args>
-struct __libcpp_is_nothrow_constructible</*is constructible*/false, _IsReference, _Tp, _Args...>
-    : public false_type
-{
-};
-
-template <class _Tp, class... _Args>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible
-    : __libcpp_is_nothrow_constructible<is_constructible<_Tp, _Args...>::value, is_reference<_Tp>::value, _Tp, _Args...>
-{
-};
-
-template <class _Tp, size_t _Ns>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp[_Ns]>
-    : __libcpp_is_nothrow_constructible<is_constructible<_Tp>::value, is_reference<_Tp>::value, _Tp>
-{
-};
-
-#endif // _LIBCPP_HAS_NO_NOEXCEPT
-
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp, class ..._Args>
-inline constexpr bool is_nothrow_constructible_v = is_nothrow_constructible<_Tp, _Args...>::value;
-#endif
-
-// is_nothrow_default_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_default_constructible
-    : public is_nothrow_constructible<_Tp>
-    {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_nothrow_default_constructible_v = is_nothrow_default_constructible<_Tp>::value;
-#endif
-
-// is_nothrow_copy_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_copy_constructible
-    : public is_nothrow_constructible<_Tp,
-                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_nothrow_copy_constructible_v = is_nothrow_copy_constructible<_Tp>::value;
-#endif
-
-// is_nothrow_move_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_move_constructible
-    : public is_nothrow_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
-    {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_nothrow_move_constructible_v = is_nothrow_move_constructible<_Tp>::value;
-#endif
-
-// is_nothrow_assignable
-
-#if __has_keyword(__is_nothrow_assignable)
-
-template <class _Tp, class _Arg>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable
-    : public integral_constant<bool, __is_nothrow_assignable(_Tp, _Arg)> {};
-
-#else
-
-template <bool, class _Tp, class _Arg> struct __libcpp_is_nothrow_assignable;
-
-template <class _Tp, class _Arg>
-struct __libcpp_is_nothrow_assignable<false, _Tp, _Arg>
-    : public false_type
-{
-};
-
-template <class _Tp, class _Arg>
-struct __libcpp_is_nothrow_assignable<true, _Tp, _Arg>
-    : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Arg>()) >
-{
-};
-
-template <class _Tp, class _Arg>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable
-    : public __libcpp_is_nothrow_assignable<is_assignable<_Tp, _Arg>::value, _Tp, _Arg>
-{
-};
-
-#endif // _LIBCPP_HAS_NO_NOEXCEPT
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp, class _Arg>
-inline constexpr bool is_nothrow_assignable_v = is_nothrow_assignable<_Tp, _Arg>::value;
-#endif
-
-// is_nothrow_copy_assignable
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_copy_assignable
-    : public is_nothrow_assignable<typename add_lvalue_reference<_Tp>::type,
-                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_nothrow_copy_assignable_v = is_nothrow_copy_assignable<_Tp>::value;
-#endif
-
-// is_nothrow_move_assignable
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_move_assignable
-    : public is_nothrow_assignable<typename add_lvalue_reference<_Tp>::type,
-                                     typename add_rvalue_reference<_Tp>::type>
-    {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_nothrow_move_assignable_v = is_nothrow_move_assignable<_Tp>::value;
-#endif
-
-// is_nothrow_destructible
-
-#if !defined(_LIBCPP_CXX03_LANG)
-
-template <bool, class _Tp> struct __libcpp_is_nothrow_destructible;
-
-template <class _Tp>
-struct __libcpp_is_nothrow_destructible<false, _Tp>
-    : public false_type
-{
-};
-
-template <class _Tp>
-struct __libcpp_is_nothrow_destructible<true, _Tp>
-    : public integral_constant<bool, noexcept(declval<_Tp>().~_Tp()) >
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible
-    : public __libcpp_is_nothrow_destructible<is_destructible<_Tp>::value, _Tp>
-{
-};
-
-template <class _Tp, size_t _Ns>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp[_Ns]>
-    : public is_nothrow_destructible<_Tp>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp&>
-    : public true_type
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp&&>
-    : public true_type
-{
-};
-
-#else
-
-template <class _Tp> struct __libcpp_nothrow_destructor
-    : public integral_constant<bool, is_scalar<_Tp>::value ||
-                                     is_reference<_Tp>::value> {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible
-    : public __libcpp_nothrow_destructor<typename remove_all_extents<_Tp>::type> {};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp[]>
-    : public false_type {};
-
-#endif
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-inline constexpr bool is_nothrow_destructible_v = is_nothrow_destructible<_Tp>::value;
-#endif
-
 // result_of
 
 #if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_TYPE_TRAITS)
 template <class _Callable> class _LIBCPP_DEPRECATED_IN_CXX17 result_of;
 
 #ifndef _LIBCPP_CXX03_LANG
 
 template <class _Fp, class ..._Args>

 __uint128_t __convert_to_integral(__uint128_t __val) { return __val; }
 #endif
 
 template <class _Tp>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
 typename __sfinae_underlying_type<_Tp>::__promoted_type
 __convert_to_integral(_Tp __val) { return __val; }
 
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-struct negation : _Not<_Tp> {};
-template<class _Tp>
-inline constexpr bool negation_v = negation<_Tp>::value;
-#endif // _LIBCPP_STD_VER > 14
-
 // These traits are used in __tree and __hash_table
 struct __extract_key_fail_tag {};
 struct __extract_key_self_tag {};
 struct __extract_key_first_tag {};
 
 template <class _ValTy, class _Key,
           class _RawValTy = typename __unconstref<_ValTy>::type>
 struct __can_extract_key

libcxx/test/libcxx/private_headers.verify.cpp

 #include <__type_traits/is_assignable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_assignable.h'}}
 #include <__type_traits/is_base_of.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_base_of.h'}}
 #include <__type_traits/is_bounded_array.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_bounded_array.h'}}
 #include <__type_traits/is_callable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_callable.h'}}
 #include <__type_traits/is_class.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_class.h'}}
 #include <__type_traits/is_compound.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_compound.h'}}
 #include <__type_traits/is_const.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_const.h'}}
 #include <__type_traits/is_constant_evaluated.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_constant_evaluated.h'}}
+#include <__type_traits/is_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_constructible.h'}}
 #include <__type_traits/is_convertible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_convertible.h'}}
 #include <__type_traits/is_copy_assignable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_copy_assignable.h'}}
+#include <__type_traits/is_copy_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_copy_constructible.h'}}
 #include <__type_traits/is_core_convertible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_core_convertible.h'}}
+#include <__type_traits/is_default_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_default_constructible.h'}}
+#include <__type_traits/is_destructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_destructible.h'}}
 #include <__type_traits/is_empty.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_empty.h'}}
 #include <__type_traits/is_enum.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_enum.h'}}
 #include <__type_traits/is_final.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_final.h'}}
 #include <__type_traits/is_floating_point.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_floating_point.h'}}
 #include <__type_traits/is_function.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_function.h'}}
 #include <__type_traits/is_fundamental.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_fundamental.h'}}
 #include <__type_traits/is_integral.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_integral.h'}}
 #include <__type_traits/is_literal_type.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_literal_type.h'}}
 #include <__type_traits/is_member_function_pointer.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_member_function_pointer.h'}}
 #include <__type_traits/is_member_object_pointer.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_member_object_pointer.h'}}
 #include <__type_traits/is_member_pointer.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_member_pointer.h'}}
 #include <__type_traits/is_move_assignable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_move_assignable.h'}}
+#include <__type_traits/is_move_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_move_constructible.h'}}
+#include <__type_traits/is_nothrow_assignable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_nothrow_assignable.h'}}
+#include <__type_traits/is_nothrow_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_nothrow_constructible.h'}}
+#include <__type_traits/is_nothrow_copy_assignable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_nothrow_copy_assignable.h'}}
+#include <__type_traits/is_nothrow_copy_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_nothrow_copy_constructible.h'}}
+#include <__type_traits/is_nothrow_default_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_nothrow_default_constructible.h'}}
+#include <__type_traits/is_nothrow_destructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_nothrow_destructible.h'}}
+#include <__type_traits/is_nothrow_move_assignable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_nothrow_move_assignable.h'}}
+#include <__type_traits/is_nothrow_move_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_nothrow_move_constructible.h'}}
 #include <__type_traits/is_null_pointer.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_null_pointer.h'}}
 #include <__type_traits/is_object.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_object.h'}}
 #include <__type_traits/is_pod.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_pod.h'}}
 #include <__type_traits/is_pointer.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_pointer.h'}}
 #include <__type_traits/is_polymorphic.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_polymorphic.h'}}
 #include <__type_traits/is_reference.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_reference.h'}}
 #include <__type_traits/is_reference_wrapper.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_reference_wrapper.h'}}
 #include <__type_traits/is_referenceable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_referenceable.h'}}
 #include <__type_traits/is_same.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_same.h'}}
 #include <__type_traits/is_scalar.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_scalar.h'}}
 #include <__type_traits/is_scoped_enum.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_scoped_enum.h'}}
 #include <__type_traits/is_signed.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_signed.h'}}
 #include <__type_traits/is_standard_layout.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_standard_layout.h'}}
 #include <__type_traits/is_trivial.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_trivial.h'}}
+#include <__type_traits/is_trivially_assignable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_trivially_assignable.h'}}
+#include <__type_traits/is_trivially_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_trivially_constructible.h'}}
+#include <__type_traits/is_trivially_copy_assignable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_trivially_copy_assignable.h'}}
+#include <__type_traits/is_trivially_copy_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_trivially_copy_constructible.h'}}
 #include <__type_traits/is_trivially_copyable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_trivially_copyable.h'}}
+#include <__type_traits/is_trivially_default_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_trivially_default_constructible.h'}}
+#include <__type_traits/is_trivially_destructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_trivially_destructible.h'}}
+#include <__type_traits/is_trivially_move_assignable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_trivially_move_assignable.h'}}
+#include <__type_traits/is_trivially_move_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_trivially_move_constructible.h'}}
 #include <__type_traits/is_unbounded_array.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_unbounded_array.h'}}
 #include <__type_traits/is_union.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_union.h'}}
 #include <__type_traits/is_unsigned.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_unsigned.h'}}
 #include <__type_traits/is_void.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_void.h'}}
 #include <__type_traits/is_volatile.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_volatile.h'}}
+#include <__type_traits/negation.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/negation.h'}}
 #include <__type_traits/rank.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/rank.h'}}
 #include <__type_traits/remove_all_extents.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/remove_all_extents.h'}}
 #include <__type_traits/remove_const.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/remove_const.h'}}
 #include <__type_traits/remove_cv.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/remove_cv.h'}}
 #include <__type_traits/remove_extent.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/remove_extent.h'}}
 #include <__type_traits/remove_pointer.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/remove_pointer.h'}}
 #include <__type_traits/remove_reference.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/remove_reference.h'}}
 #include <__type_traits/remove_volatile.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/remove_volatile.h'}}
 #include <__type_traits/type_identity.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/type_identity.h'}}
 #include <__type_traits/underlying_type.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/underlying_type.h'}}
+#include <__type_traits/void_t.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/void_t.h'}}
 #include <__utility/as_const.h> // expected-error@*:* {{use of private header from outside its module: '__utility/as_const.h'}}
 #include <__utility/auto_cast.h> // expected-error@*:* {{use of private header from outside its module: '__utility/auto_cast.h'}}
 #include <__utility/cmp.h> // expected-error@*:* {{use of private header from outside its module: '__utility/cmp.h'}}
 #include <__utility/declval.h> // expected-error@*:* {{use of private header from outside its module: '__utility/declval.h'}}
 #include <__utility/exchange.h> // expected-error@*:* {{use of private header from outside its module: '__utility/exchange.h'}}
 #include <__utility/forward.h> // expected-error@*:* {{use of private header from outside its module: '__utility/forward.h'}}
 #include <__utility/in_place.h> // expected-error@*:* {{use of private header from outside its module: '__utility/in_place.h'}}
 #include <__utility/integer_sequence.h> // expected-error@*:* {{use of private header from outside its module: '__utility/integer_sequence.h'}}