[libc++] Granularize the rest of type_traits

[philnik]

• Fix stuff

[philnik]

• Generate files

[philnik]

• Remove include

[ldionne]

Please wait until ~ Thursday next week before shipping this. It touches a lot of stuff and I want to make cherry-picks for LLVM 15 as easy as possible.

Also, pending green CI as usual.

libcxx/include/__fwd/hash.h

9–10

Please check the other files as well.

libcxx/include/type_traits

422

Per live review, can you please provide a link to a bug report regarding the poisoned hash helper test? This shouldn't be necessary.

426

You're missing an include of can_extract_key.h. I know it's not needed in <type_traits>, but we decided a while back that top-level headers would include all the files in their detail directory, so let's be consistent.

Per our discussion, it might make sense to change this approach to only include the public interface from our top-level headers, but let's not try to change the world in this commit.

[philnik]

• Address comments

[philnik]

• Fix CI

[philnik]

• Next try

[philnik]

• Fix modulemap

[philnik]

Rebased

libcxx/include/CMakeLists.txt

set(files
   __functional/pointer_to_binary_function.h
   __functional/pointer_to_unary_function.h
   __functional/ranges_operations.h
   __functional/reference_wrapper.h
   __functional/unary_function.h
   __functional/unary_negate.h
   __functional/unwrap_ref.h
   __functional/weak_result_type.h
+  __fwd/hash.h
+  __fwd/pair.h
   __fwd/span.h
   __fwd/string_view.h
   __hash_table
   __ios/fpos.h
   __iterator/access.h
   __iterator/advance.h
   __iterator/back_insert_iterator.h
   __iterator/bounded_iter.h
set(files
   __type_traits/add_lvalue_reference.h
   __type_traits/add_pointer.h
   __type_traits/add_rvalue_reference.h
   __type_traits/add_volatile.h
   __type_traits/aligned_storage.h
   __type_traits/aligned_union.h
   __type_traits/alignment_of.h
   __type_traits/apply_cv.h
+  __type_traits/can_extract_key.h
   __type_traits/common_reference.h
   __type_traits/common_type.h
   __type_traits/conditional.h
   __type_traits/conjunction.h
   __type_traits/copy_cv.h
   __type_traits/copy_cvref.h
   __type_traits/decay.h
+  __type_traits/dependent_type.h
   __type_traits/disjunction.h
   __type_traits/enable_if.h
   __type_traits/extent.h
   __type_traits/has_unique_object_representation.h
   __type_traits/has_virtual_destructor.h
   __type_traits/integral_constant.h
   __type_traits/is_abstract.h
   __type_traits/is_aggregate.h
   __type_traits/is_arithmetic.h
   __type_traits/is_array.h
   __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_char_like_type.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_implicitly_default_constructible.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
set(files
   __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_signed_integer.h
   __type_traits/is_standard_layout.h
+  __type_traits/is_swappable.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_unsigned_integer.h
   __type_traits/is_valid_expansion.h
   __type_traits/is_void.h
   __type_traits/is_volatile.h
   __type_traits/lazy.h
   __type_traits/make_32_64_or_128_bit.h
+  __type_traits/make_const_lvalue_ref.h
   __type_traits/make_signed.h
   __type_traits/make_unsigned.h
+  __type_traits/maybe_const.h
   __type_traits/nat.h
   __type_traits/negation.h
   __type_traits/promote.h
   __type_traits/rank.h
   __type_traits/remove_all_extents.h
   __type_traits/remove_const.h
+  __type_traits/remove_const_ref.h
   __type_traits/remove_cv.h
   __type_traits/remove_cvref.h
   __type_traits/remove_extent.h
   __type_traits/remove_pointer.h
   __type_traits/remove_reference.h
   __type_traits/remove_volatile.h
+  __type_traits/result_of.h
   __type_traits/type_identity.h
   __type_traits/type_list.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/convert_to_integral.h
   __utility/declval.h
   __utility/exchange.h
   __utility/forward.h
   __utility/in_place.h
   __utility/integer_sequence.h
   __utility/move.h
   __utility/pair.h
   __utility/piecewise_construct.h

libcxx/include/__algorithm/copy_backward.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___ALGORITHM_COPY_BACKWARD_H
 #define _LIBCPP___ALGORITHM_COPY_BACKWARD_H
 
 #include <__algorithm/copy.h>
 #include <__algorithm/unwrap_iter.h>
 #include <__config>
 #include <__iterator/iterator_traits.h>
 #include <__iterator/reverse_iterator.h>
+#include <__utility/pair.h>
 #include <cstring>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD

libcxx/include/__algorithm/copy_n.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___ALGORITHM_COPY_N_H
 #define _LIBCPP___ALGORITHM_COPY_N_H
 
 #include <__algorithm/copy.h>
 #include <__config>
 #include <__iterator/iterator_traits.h>
+#include <__utility/convert_to_integral.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 

libcxx/include/__algorithm/fill_n.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___ALGORITHM_FILL_N_H
 #define _LIBCPP___ALGORITHM_FILL_N_H
 
 #include <__config>
 #include <__iterator/iterator_traits.h>
+#include <__utility/convert_to_integral.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 

libcxx/include/__algorithm/for_each_n.h

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // 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___ALGORITHM_FOR_EACH_N_H
 #define _LIBCPP___ALGORITHM_FOR_EACH_N_H
 
 #include <__config>
+#include <__utility/convert_to_integral.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 

libcxx/include/__algorithm/generate_n.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___ALGORITHM_GENERATE_N_H
 #define _LIBCPP___ALGORITHM_GENERATE_N_H
 
 #include <__config>
+#include <__utility/convert_to_integral.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 

libcxx/include/__algorithm/search_n.h

 #include <__algorithm/iterator_operations.h>
 #include <__config>
 #include <__functional/identity.h>
 #include <__iterator/advance.h>
 #include <__iterator/concepts.h>
 #include <__iterator/distance.h>
 #include <__iterator/iterator_traits.h>
 #include <__ranges/concepts.h>
+#include <__utility/convert_to_integral.h>
 #include <__utility/pair.h>
 #include <type_traits>  // __convert_to_integral
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD

libcxx/include/__compare/compare_three_way_result.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___COMPARE_COMPARE_THREE_WAY_RESULT_H
 #define _LIBCPP___COMPARE_COMPARE_THREE_WAY_RESULT_H
 
 #include <__config>
+#include <__type_traits/make_const_lvalue_ref.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 

libcxx/include/__compare/three_way_comparable.h

 
 #include <__compare/common_comparison_category.h>
 #include <__compare/ordering.h>
 #include <__concepts/common_reference_with.h>
 #include <__concepts/equality_comparable.h>
 #include <__concepts/same_as.h>
 #include <__concepts/totally_ordered.h>
 #include <__config>
+#include <__type_traits/make_const_lvalue_ref.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 

libcxx/include/__concepts/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___CONCEPTS_ASSIGNABLE_H
 #define _LIBCPP___CONCEPTS_ASSIGNABLE_H
 
 #include <__concepts/common_reference_with.h>
 #include <__concepts/same_as.h>
 #include <__config>
+#include <__type_traits/make_const_lvalue_ref.h>
 #include <__utility/forward.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD

libcxx/include/__concepts/equality_comparable.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___CONCEPTS_EQUALITY_COMPARABLE_H
 #define _LIBCPP___CONCEPTS_EQUALITY_COMPARABLE_H
 
 #include <__concepts/boolean_testable.h>
 #include <__concepts/common_reference_with.h>
 #include <__config>
+#include <__type_traits/make_const_lvalue_ref.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 

libcxx/include/__concepts/swappable.h

 #include <__concepts/assignable.h>
 #include <__concepts/class_or_enum.h>
 #include <__concepts/common_reference_with.h>
 #include <__concepts/constructible.h>
 #include <__config>
 #include <__utility/exchange.h>
 #include <__utility/forward.h>
 #include <__utility/move.h>
+#include <__utility/swap.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 

libcxx/include/__functional/hash.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___FUNCTIONAL_HASH_H
 #define _LIBCPP___FUNCTIONAL_HASH_H
 
 #include <__config>
 #include <__functional/unary_function.h>
+#include <__fwd/hash.h>
 #include <__tuple>
 #include <__utility/forward.h>
 #include <__utility/move.h>
 #include <__utility/pair.h>
 #include <__utility/swap.h>
 #include <cstddef>
 #include <cstdint>
 #include <cstring>

libcxx/include/__fwd/hash.h

-// -*- C++ -*-
 //===---------------------------------------------------------------------===//
 //
 // 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_FWD_SPAN_H
-#define _LIBCPP_FWD_SPAN_H
+#ifndef _LIBCPP___FWD_HASH_H
+#define _LIBCPP___FWD_HASH_H
 
 #include <__config>
-#include <cstddef>
-#include <limits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER > 17
-
-inline constexpr size_t dynamic_extent = numeric_limits<size_t>::max();
-template <typename _Tp, size_t _Extent = dynamic_extent> class span;
-
-#endif
+template <class>
+struct _LIBCPP_TEMPLATE_VIS hash;
 
 _LIBCPP_END_NAMESPACE_STD
 
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_FWD_SPAN_H
+#endif // _LIBCPP___FWD_HASH_H

libcxx/include/__fwd/pair.h

-// -*- C++ -*-
 //===---------------------------------------------------------------------===//
 //
 // 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_FWD_SPAN_H
-#define _LIBCPP_FWD_SPAN_H
+#ifndef _LIBCPP___FWD_PAIR_H
+#define _LIBCPP___FWD_PAIR_H
 
 #include <__config>
-#include <cstddef>
-#include <limits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER > 17
-
-inline constexpr size_t dynamic_extent = numeric_limits<size_t>::max();
-template <typename _Tp, size_t _Extent = dynamic_extent> class span;
-
-#endif
+template <class, class>
+struct _LIBCPP_TEMPLATE_VIS pair;
 
 _LIBCPP_END_NAMESPACE_STD
 
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_FWD_SPAN_H
+#endif // _LIBCPP___FWD_PAIR_H

libcxx/include/__fwd/span.h

 // -*- C++ -*-
 //===---------------------------------------------------------------------===//
 //
 // 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_FWD_SPAN_H
-#define _LIBCPP_FWD_SPAN_H
+#ifndef _LIBCPP___FWD_SPAN_H
+#define _LIBCPP___FWD_SPAN_H
 
 #include <__config>
 #include <cstddef>
 #include <limits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif

 template <typename _Tp, size_t _Extent = dynamic_extent> class span;
 
 #endif
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
-#endif // _LIBCPP_FWD_SPAN_H
+#endif // _LIBCPP___FWD_SPAN_H

libcxx/include/__fwd/string_view.h

 // -*- C++ -*-
 //===---------------------------------------------------------------------===//
 //
 // 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_FWD_STRING_VIEW_H
-#define _LIBCPP_FWD_STRING_VIEW_H
+#ifndef _LIBCPP___FWD_STRING_VIEW_H
+#define _LIBCPP___FWD_STRING_VIEW_H
 
 #include <__config>
 #include <iosfwd> // char_traits
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 

 typedef basic_string_view<char16_t> u16string_view;
 typedef basic_string_view<char32_t> u32string_view;
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 typedef basic_string_view<wchar_t>  wstring_view;
 #endif
 
 _LIBCPP_END_NAMESPACE_STD
 
-#endif // _LIBCPP_FWD_STRING_VIEW_H
+#endif // _LIBCPP___FWD_STRING_VIEW_H

libcxx/include/__hash_table

 #include <__algorithm/max.h>
 #include <__algorithm/min.h>
 #include <__assert>
 #include <__bits> // __libcpp_clz
 #include <__config>
 #include <__debug>
 #include <__functional/hash.h>
 #include <__iterator/iterator_traits.h>
+#include <__type_traits/can_extract_key.h>
 #include <__utility/swap.h>
 #include <cmath>
 #include <initializer_list>
 #include <memory>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header

libcxx/include/__iterator/advance.h

 #ifndef _LIBCPP___ITERATOR_ADVANCE_H
 #define _LIBCPP___ITERATOR_ADVANCE_H
 
 #include <__assert>
 #include <__config>
 #include <__iterator/concepts.h>
 #include <__iterator/incrementable_traits.h>
 #include <__iterator/iterator_traits.h>
+#include <__utility/convert_to_integral.h>
 #include <__utility/move.h>
 #include <__utility/unreachable.h>
 #include <concepts>
 #include <cstdlib>
 #include <limits>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)

libcxx/include/__iterator/iterator_traits.h

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // 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___ITERATOR_ITERATOR_TRAITS_H
 #define _LIBCPP___ITERATOR_ITERATOR_TRAITS_H
 
 #include <__config>
+#include <__fwd/pair.h>
 #include <__iterator/incrementable_traits.h>
 #include <__iterator/readable_traits.h>
 #include <concepts>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif

libcxx/include/__memory/compressed_pair.h

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // 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___MEMORY_COMPRESSED_PAIR_H
 #define _LIBCPP___MEMORY_COMPRESSED_PAIR_H
 
 #include <__config>
+#include <__type_traits/dependent_type.h>
 #include <__utility/forward.h>
 #include <__utility/move.h>
 #include <tuple> // needed in c++03 for some constructors
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif

libcxx/include/__ranges/join_view.h

 #include <__iterator/iter_swap.h>
 #include <__iterator/iterator_traits.h>
 #include <__ranges/access.h>
 #include <__ranges/all.h>
 #include <__ranges/concepts.h>
 #include <__ranges/non_propagating_cache.h>
 #include <__ranges/range_adaptor.h>
 #include <__ranges/view_interface.h>
+#include <__type_traits/maybe_const.h>
 #include <__utility/forward.h>
 #include <optional>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
constexpr void __satisfy() {
       }
 
       if constexpr (__ref_is_glvalue)
         __inner_.reset();
     }
 
   public:
     using iterator_concept = _If<
-      __ref_is_glvalue && bidirectional_range<_Base> && bidirectional_range<range_reference_t<_Base>> && 
+      __ref_is_glvalue && bidirectional_range<_Base> && bidirectional_range<range_reference_t<_Base>> &&
           common_range<range_reference_t<_Base>>,
       bidirectional_iterator_tag,
       _If<
         __ref_is_glvalue && forward_range<_Base> && forward_range<range_reference_t<_Base>>,
         forward_iterator_tag,
         input_iterator_tag
       >
     >;
friend constexpr void iter_swap(const __iterator& __x, const __iterator& __y)
       requires indirectly_swappable<_Inner>
     {
       return ranges::iter_swap(*__x.__inner_, *__y.__inner_);
     }
   };
 
   template<class _Range>
   explicit join_view(_Range&&) -> join_view<views::all_t<_Range>>;
-  
 namespace views {
 namespace __join_view {
 struct __fn : __range_adaptor_closure<__fn> {
   template<class _Range>
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
   constexpr auto operator()(_Range&& __range) const
     noexcept(noexcept(join_view<all_t<_Range&&>>(std::forward<_Range>(__range))))
     -> decltype(      join_view<all_t<_Range&&>>(std::forward<_Range>(__range)))

libcxx/include/__ranges/lazy_split_view.h

 #include <__ranges/access.h>
 #include <__ranges/all.h>
 #include <__ranges/concepts.h>
 #include <__ranges/non_propagating_cache.h>
 #include <__ranges/range_adaptor.h>
 #include <__ranges/single_view.h>
 #include <__ranges/subrange.h>
 #include <__ranges/view_interface.h>
+#include <__type_traits/maybe_const.h>
 #include <__utility/forward.h>
 #include <__utility/move.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 

libcxx/include/__ranges/take_view.h

 #include <__ranges/concepts.h>
 #include <__ranges/empty_view.h>
 #include <__ranges/enable_borrowed_range.h>
 #include <__ranges/iota_view.h>
 #include <__ranges/range_adaptor.h>
 #include <__ranges/size.h>
 #include <__ranges/subrange.h>
 #include <__ranges/view_interface.h>
+#include <__type_traits/maybe_const.h>
 #include <__utility/auto_cast.h>
 #include <__utility/forward.h>
 #include <__utility/move.h>
 #include <concepts>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header

libcxx/include/__ranges/transform_view.h

 #include <__ranges/access.h>
 #include <__ranges/all.h>
 #include <__ranges/concepts.h>
 #include <__ranges/copyable_box.h>
 #include <__ranges/empty.h>
 #include <__ranges/range_adaptor.h>
 #include <__ranges/size.h>
 #include <__ranges/view_interface.h>
+#include <__type_traits/maybe_const.h>
 #include <__utility/forward.h>
 #include <__utility/in_place.h>
 #include <__utility/move.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif

libcxx/include/__threading_support

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // 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___THREADING_SUPPORT
 #define _LIBCPP___THREADING_SUPPORT
 
 #include <__availability>
 #include <__chrono/convert_to_timespec.h>
 #include <__chrono/duration.h>
 #include <__config>
+#include <__fwd/hash.h>
 #include <__thread/poll_with_backoff.h>
 #include <errno.h>
 #include <iosfwd>
 #include <limits>
 
 #ifdef __MVS__
 # include <__support/ibm/nanosleep.h>
 #endif

libcxx/include/__tree

 
 #include <__algorithm/min.h>
 #include <__assert>
 #include <__config>
 #include <__debug>
 #include <__iterator/distance.h>
 #include <__iterator/iterator_traits.h>
 #include <__iterator/next.h>
+#include <__type_traits/can_extract_key.h>
 #include <__utility/forward.h>
 #include <__utility/swap.h>
 #include <limits>
 #include <memory>
 #include <stdexcept>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header

libcxx/include/__tuple

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // 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___TUPLE
 #define _LIBCPP___TUPLE
 
 #include <__config>
+#include <__fwd/pair.h>
 #include <cstddef>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 

libcxx/include/__type_traits/can_extract_key.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_CAN_EXTRACT_KEY_H
+#define _LIBCPP___TYPE_TRAITS_CAN_EXTRACT_KEY_H
+
+#include <__config>
+#include <__fwd/pair.h>
+#include <__type_traits/conditional.h>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_same.h>
+#include <__type_traits/remove_const.h>
+#include <__type_traits/remove_const_ref.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// 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
+    : conditional<_IsSame<_RawValTy, _Key>::value, __extract_key_self_tag,
+                  __extract_key_fail_tag>::type {};
+
+template <class _Pair, class _Key, class _First, class _Second>
+struct __can_extract_key<_Pair, _Key, pair<_First, _Second> >
+    : conditional<_IsSame<typename remove_const<_First>::type, _Key>::value,
+                  __extract_key_first_tag, __extract_key_fail_tag>::type {};
+
+// __can_extract_map_key uses true_type/false_type instead of the tags.
+// It returns true if _Key != _ContainerValueTy (the container is a map not a set)
+// and _ValTy == _Key.
+template <class _ValTy, class _Key, class _ContainerValueTy,
+          class _RawValTy = typename __unconstref<_ValTy>::type>
+struct __can_extract_map_key
+    : integral_constant<bool, _IsSame<_RawValTy, _Key>::value> {};
+
+// This specialization returns __extract_key_fail_tag for non-map containers
+// because _Key == _ContainerValueTy
+template <class _ValTy, class _Key, class _RawValTy>
+struct __can_extract_map_key<_ValTy, _Key, _Key, _RawValTy>
+    : false_type {};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_CAN_EXTRACT_KEY_H

libcxx/include/__type_traits/dependent_type.h

-// -*- C++ -*-
-//===---------------------------------------------------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // 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_FWD_SPAN_H
-#define _LIBCPP_FWD_SPAN_H
+#ifndef _LIBCPP___TYPE_TRAITS_DEPENDENT_TYPE_H
+#define _LIBCPP___TYPE_TRAITS_DEPENDENT_TYPE_H
 
 #include <__config>
-#include <cstddef>
-#include <limits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER > 17
-
-inline constexpr size_t dynamic_extent = numeric_limits<size_t>::max();
-template <typename _Tp, size_t _Extent = dynamic_extent> class span;
-
-#endif
+template <class _Tp, bool>
+struct _LIBCPP_TEMPLATE_VIS __dependent_type : public _Tp {};
 
 _LIBCPP_END_NAMESPACE_STD
 
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_FWD_SPAN_H
+#endif // _LIBCPP___TYPE_TRAITS_DEPENDENT_TYPE_H

libcxx/include/__type_traits/is_char_like_type.h

-// -*- C++ -*-
-//===---------------------------------------------------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // 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_FWD_SPAN_H
-#define _LIBCPP_FWD_SPAN_H
+#ifndef _LIBCPP___TYPE_TRAITS_IS_CHAR_LIKE_TYPE_H
+#define _LIBCPP___TYPE_TRAITS_IS_CHAR_LIKE_TYPE_H
 
 #include <__config>
-#include <cstddef>
-#include <limits>
+#include <__type_traits/conjunction.h>
+#include <__type_traits/is_standard_layout.h>
+#include <__type_traits/is_trivial.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER > 17
-
-inline constexpr size_t dynamic_extent = numeric_limits<size_t>::max();
-template <typename _Tp, size_t _Extent = dynamic_extent> class span;
-
-#endif
+template <class _CharT>
+using _IsCharLikeType = _And<is_standard_layout<_CharT>, is_trivial<_CharT> >;
 
 _LIBCPP_END_NAMESPACE_STD
 
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_FWD_SPAN_H
+#endif // _LIBCPP___TYPE_TRAITS_IS_CHAR_LIKE_TYPE_H

libcxx/include/__type_traits/is_implicitly_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_IMPLICITLY_DEFAULT_CONSTRUCTIBLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_IMPLICITLY_DEFAULT_CONSTRUCTIBLE_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_default_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#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
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_IMPLICITLY_DEFAULT_CONSTRUCTIBLE_H

libcxx/include/__type_traits/is_swappable.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_SWAPPABLE_H
+#define _LIBCPP___TYPE_TRAITS_IS_SWAPPABLE_H
+
+#include <__config>
+#include <__type_traits/add_lvalue_reference.h>
+#include <__type_traits/conditional.h>
+#include <__type_traits/enable_if.h>
+#include <__type_traits/is_move_assignable.h>
+#include <__type_traits/is_move_constructible.h>
+#include <__type_traits/is_nothrow_move_assignable.h>
+#include <__type_traits/is_nothrow_move_constructible.h>
+#include <__type_traits/is_referenceable.h>
+#include <__type_traits/is_same.h>
+#include <__type_traits/is_void.h>
+#include <__type_traits/nat.h>
+#include <__utility/declval.h>
+#include <cstddef>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> struct __is_swappable;
+template <class _Tp> struct __is_nothrow_swappable;
+
+
+#ifndef _LIBCPP_CXX03_LANG
+template <class _Tp>
+using __swap_result_t = typename enable_if<is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value>::type;
+#else
+template <class>
+using __swap_result_t = void;
+#endif
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_AFTER_CXX17 __swap_result_t<_Tp>
+swap(_Tp& __x, _Tp& __y) _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value &&
+                                    is_nothrow_move_assignable<_Tp>::value);
+
+template<class _Tp, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+typename enable_if<
+    __is_swappable<_Tp>::value
+>::type
+swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value);
+
+namespace __detail
+{
+// ALL generic swap overloads MUST already have a declaration available at this point.
+
+template <class _Tp, class _Up = _Tp,
+          bool _NotVoid = !is_void<_Tp>::value && !is_void<_Up>::value>
+struct __swappable_with
+{
+    template <class _LHS, class _RHS>
+    static decltype(swap(declval<_LHS>(), declval<_RHS>()))
+    __test_swap(int);
+    template <class, class>
+    static __nat __test_swap(long);
+
+    // Extra parens are needed for the C++03 definition of decltype.
+    typedef decltype((__test_swap<_Tp, _Up>(0))) __swap1;
+    typedef decltype((__test_swap<_Up, _Tp>(0))) __swap2;
+
+    static const bool value = _IsNotSame<__swap1, __nat>::value
+                           && _IsNotSame<__swap2, __nat>::value;
+};
+
+template <class _Tp, class _Up>
+struct __swappable_with<_Tp, _Up,  false> : false_type {};
+
+template <class _Tp, class _Up = _Tp, bool _Swappable = __swappable_with<_Tp, _Up>::value>
+struct __nothrow_swappable_with {
+  static const bool value =
+#ifndef _LIBCPP_HAS_NO_NOEXCEPT
+      noexcept(swap(declval<_Tp>(), declval<_Up>()))
+  &&  noexcept(swap(declval<_Up>(), declval<_Tp>()));
+#else
+      false;
+#endif
+};
+
+template <class _Tp, class _Up>
+struct __nothrow_swappable_with<_Tp, _Up, false> : false_type {};
+
+} // namespace __detail
+
+template <class _Tp>
+struct __is_swappable
+    : public integral_constant<bool, __detail::__swappable_with<_Tp&>::value>
+{
+};
+
+template <class _Tp>
+struct __is_nothrow_swappable
+    : public integral_constant<bool, __detail::__nothrow_swappable_with<_Tp&>::value>
+{
+};
+
+#if _LIBCPP_STD_VER > 14
+
+template <class _Tp, class _Up>
+struct _LIBCPP_TEMPLATE_VIS is_swappable_with
+    : public integral_constant<bool, __detail::__swappable_with<_Tp, _Up>::value>
+{
+};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_swappable
+    : public conditional<
+        __is_referenceable<_Tp>::value,
+        is_swappable_with<
+            typename add_lvalue_reference<_Tp>::type,
+            typename add_lvalue_reference<_Tp>::type>,
+        false_type
+    >::type
+{
+};
+
+template <class _Tp, class _Up>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_swappable_with
+    : public integral_constant<bool, __detail::__nothrow_swappable_with<_Tp, _Up>::value>
+{
+};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_nothrow_swappable
+    : public conditional<
+        __is_referenceable<_Tp>::value,
+        is_nothrow_swappable_with<
+            typename add_lvalue_reference<_Tp>::type,
+            typename add_lvalue_reference<_Tp>::type>,
+        false_type
+    >::type
+{
+};
+
+template <class _Tp, class _Up>
+inline constexpr bool is_swappable_with_v = is_swappable_with<_Tp, _Up>::value;
+
+template <class _Tp>
+inline constexpr bool is_swappable_v = is_swappable<_Tp>::value;
+
+template <class _Tp, class _Up>
+inline constexpr bool is_nothrow_swappable_with_v = is_nothrow_swappable_with<_Tp, _Up>::value;
+
+template <class _Tp>
+inline constexpr bool is_nothrow_swappable_v = is_nothrow_swappable<_Tp>::value;
+
+#endif // _LIBCPP_STD_VER > 14
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_SWAPPABLE_H

libcxx/include/__type_traits/make_const_lvalue_ref.h

-// -*- C++ -*-
-//===---------------------------------------------------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // 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_FWD_SPAN_H
-#define _LIBCPP_FWD_SPAN_H
+#ifndef _LIBCPP___TYPE_TRAITS_MAKE_CONST_LVALUE_REF_H
+#define _LIBCPP___TYPE_TRAITS_MAKE_CONST_LVALUE_REF_H
 
 #include <__config>
-#include <cstddef>
-#include <limits>
+#include <__type_traits/remove_reference.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER > 17
-
-inline constexpr size_t dynamic_extent = numeric_limits<size_t>::max();
-template <typename _Tp, size_t _Extent = dynamic_extent> class span;
-
-#endif
+template<class _Tp>
+using __make_const_lvalue_ref = const typename remove_reference<_Tp>::type&;
 
 _LIBCPP_END_NAMESPACE_STD
 
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_FWD_SPAN_H
+#endif // _LIBCPP___TYPE_TRAITS_MAKE_CONST_LVALUE_REF_H

libcxx/include/__type_traits/maybe_const.h

-// -*- C++ -*-
-//===---------------------------------------------------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // 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_FWD_SPAN_H
-#define _LIBCPP_FWD_SPAN_H
+#ifndef _LIBCPP___TYPE_TRAITS_MAYBE_CONST_H
+#define _LIBCPP___TYPE_TRAITS_MAYBE_CONST_H
 
 #include <__config>
-#include <cstddef>
-#include <limits>
+#include <__type_traits/conditional.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER > 17
-
-inline constexpr size_t dynamic_extent = numeric_limits<size_t>::max();
-template <typename _Tp, size_t _Extent = dynamic_extent> class span;
-
-#endif
+template<bool _Const, class _Tp>
+using __maybe_const = typename conditional<_Const, const _Tp, _Tp>::type;
 
 _LIBCPP_END_NAMESPACE_STD
 
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_FWD_SPAN_H
+#endif // _LIBCPP___TYPE_TRAITS_MAYBE_CONST_H

libcxx/include/__type_traits/remove_const_ref.h

-// -*- C++ -*-
-//===---------------------------------------------------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // 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_FWD_SPAN_H
-#define _LIBCPP_FWD_SPAN_H
+#ifndef _LIBCPP___TYPE_TRAITS_REMOVE_CONST_REF_H
+#define _LIBCPP___TYPE_TRAITS_REMOVE_CONST_REF_H
 
 #include <__config>
-#include <cstddef>
-#include <limits>
+#include <__type_traits/remove_const.h>
+#include <__type_traits/remove_reference.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER > 17
-
-inline constexpr size_t dynamic_extent = numeric_limits<size_t>::max();
-template <typename _Tp, size_t _Extent = dynamic_extent> class span;
-
-#endif
+template <class _Tp>
+struct __unconstref {
+    typedef _LIBCPP_NODEBUG typename remove_const<typename remove_reference<_Tp>::type>::type type;
+};
 
 _LIBCPP_END_NAMESPACE_STD
 
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_FWD_SPAN_H
+#endif // _LIBCPP___TYPE_TRAITS_REMOVE_CONST_REF_H

libcxx/include/__type_traits/result_of.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_RESULT_OF_H
+#define _LIBCPP___TYPE_TRAITS_RESULT_OF_H
+
+#include <__config>
+#include <__functional/invoke.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// result_of
+
+#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_TYPE_TRAITS)
+template <class _Callable> class _LIBCPP_DEPRECATED_IN_CXX17 result_of;
+
+template <class _Fp, class ..._Args>
+class _LIBCPP_TEMPLATE_VIS result_of<_Fp(_Args...)>
+    : public __invoke_of<_Fp, _Args...>
+{
+};
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp> using result_of_t _LIBCPP_DEPRECATED_IN_CXX17 = typename result_of<_Tp>::type;
+#endif // _LIBCPP_STD_VER > 11
+#endif // _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_TYPE_TRAITS)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___TYPE_TRAITS_RESULT_OF_H

libcxx/include/__utility/convert_to_integral.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___UTILITY_CONVERT_TO_INTEGRAL_H
+#define _LIBCPP___UTILITY_CONVERT_TO_INTEGRAL_H
+
+#include <__config>
+#include <__type_traits/enable_if.h>
+#include <__type_traits/is_enum.h>
+#include <__type_traits/is_floating_point.h>
+#include <__type_traits/underlying_type.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+int __convert_to_integral(int __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+unsigned __convert_to_integral(unsigned __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+long __convert_to_integral(long __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+unsigned long __convert_to_integral(unsigned long __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+long long __convert_to_integral(long long __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+unsigned long long __convert_to_integral(unsigned long long __val) {return __val; }
+
+template<typename _Fp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+typename enable_if<is_floating_point<_Fp>::value, long long>::type
+ __convert_to_integral(_Fp __val) { return __val; }
+
+#ifndef _LIBCPP_HAS_NO_INT128
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+__int128_t __convert_to_integral(__int128_t __val) { return __val; }
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+__uint128_t __convert_to_integral(__uint128_t __val) { return __val; }
+#endif
+
+template <class _Tp, bool = is_enum<_Tp>::value>
+struct __sfinae_underlying_type
+{
+    typedef typename underlying_type<_Tp>::type type;
+    typedef decltype(((type)1) + 0) __promoted_type;
+};
+
+template <class _Tp>
+struct __sfinae_underlying_type<_Tp, false> {};
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+typename __sfinae_underlying_type<_Tp>::__promoted_type
+__convert_to_integral(_Tp __val) { return __val; }
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___UTILITY_CONVERT_TO_INTEGRAL_H

libcxx/include/__utility/pair.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___UTILITY_PAIR_H
 #define _LIBCPP___UTILITY_PAIR_H
 
 #include <__compare/common_comparison_category.h>
 #include <__compare/synth_three_way.h>
 #include <__config>
 #include <__functional/unwrap_ref.h>
 #include <__tuple>
+#include <__type_traits/is_implicitly_default_constructible.h>
 #include <__utility/forward.h>
 #include <__utility/move.h>
 #include <__utility/piecewise_construct.h>
 #include <cstddef>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header

libcxx/include/bitset

 */
 
 #include <__algorithm/fill.h>
 #include <__assert> // all public C++ headers provide the assertion handler
 #include <__bit_reference>
 #include <__config>
 #include <__functional/hash.h>
 #include <__functional/unary_function.h>
+#include <__type_traits/is_char_like_type.h>
 #include <climits>
 #include <cstddef>
 #include <stdexcept>
 #include <version>
 
 // standard-mandated includes
 #include <iosfwd>
 #include <string>

libcxx/include/experimental/propagate_const

/*
   template <class T> struct greater_equal<experimental::fundamentals_v2::propagate_const<T>>;
 
 } // namespace std
 
 */
 
 #include <__assert> // all public C++ headers provide the assertion handler
 #include <__functional/operations.h>
+#include <__fwd/hash.h>
 #include <__utility/forward.h>
 #include <__utility/move.h>
 #include <__utility/swap.h>
 #include <experimental/__config>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header

libcxx/include/module.modulemap.in

module __algorithm {
       module inplace_merge                   { private header "__algorithm/inplace_merge.h" }
       module is_heap                         { private header "__algorithm/is_heap.h" }
       module is_heap_until                   { private header "__algorithm/is_heap_until.h" }
       module is_partitioned                  { private header "__algorithm/is_partitioned.h" }
       module is_permutation                  { private header "__algorithm/is_permutation.h" }
       module is_sorted                       { private header "__algorithm/is_sorted.h" }
       module is_sorted_until                 { private header "__algorithm/is_sorted_until.h" }
       module iter_swap                       { private header "__algorithm/iter_swap.h" }
-      module iterator_operations             { private header "__algorithm/iterator_operations.h" }
+      module iterator_operations             {
+        private header "__algorithm/iterator_operations.h"
+        export *
+      }
       module lexicographical_compare         { private header "__algorithm/lexicographical_compare.h" }
       module lower_bound                     { private header "__algorithm/lower_bound.h" }
       module make_heap                       { private header "__algorithm/make_heap.h" }
       module make_projected                  { private header "__algorithm/make_projected.h" }
       module max                             { private header "__algorithm/max.h" }
       module max_element                     { private header "__algorithm/max_element.h" }
       module merge                           { private header "__algorithm/merge.h" }
       module min                             { private header "__algorithm/min.h" }
module __functional {
       module bind_front                 { private header "__functional/bind_front.h" }
       module binder1st                  { private header "__functional/binder1st.h" }
       module binder2nd                  { private header "__functional/binder2nd.h" }
       module boyer_moore_searcher       { private header "__functional/boyer_moore_searcher.h" }
       module compose                    { private header "__functional/compose.h" }
       module default_searcher           { private header "__functional/default_searcher.h" }
       module function                   { private header "__functional/function.h" }
       module hash                       { private header "__functional/hash.h" }
+      module hash_fwd                   { private header "__fwd/hash.h" }
       module identity                   { private header "__functional/identity.h" }
       module invoke                     { private header "__functional/invoke.h" }
       module is_transparent             { private header "__functional/is_transparent.h" }
       module mem_fn                     { private header "__functional/mem_fn.h" }
       module mem_fun_ref                { private header "__functional/mem_fun_ref.h" }
       module not_fn                     { private header "__functional/not_fn.h" }
       module operations                 { private header "__functional/operations.h" }
       module perfect_forward            { private header "__functional/perfect_forward.h" }
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 aligned_storage                    { private header "__type_traits/aligned_storage.h" }
-    module aligned_union                      { private header "__type_traits/aligned_union.h" }
-    module alignment_of                       { private header "__type_traits/alignment_of.h" }
-    module apply_cv                           { private header "__type_traits/apply_cv.h" }
-    module common_reference                   { private header "__type_traits/common_reference.h" }
-    module common_type                        { private header "__type_traits/common_type.h" }
-    module conditional                        { private header "__type_traits/conditional.h" }
-    module conjunction                        { private header "__type_traits/conjunction.h" }
-    module copy_cv                            { private header "__type_traits/copy_cv.h" }
-    module copy_cvref                         { private header "__type_traits/copy_cvref.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_convertible             { private header "__type_traits/is_nothrow_convertible.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_primary_template                { private header "__type_traits/is_primary_template.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_signed_integer                  { private header "__type_traits/is_signed_integer.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_unsigned_integer                { private header "__type_traits/is_unsigned_integer.h" }
-    module is_valid_expansion                 { private header "__type_traits/is_valid_expansion.h" }
-    module is_void                            { private header "__type_traits/is_void.h" }
-    module is_volatile                        { private header "__type_traits/is_volatile.h" }
-    module lazy                               { private header "__type_traits/lazy.h" }
-    module make_32_64_or_128_bit              { private header "__type_traits/make_32_64_or_128_bit.h" }
-    module make_signed                        { private header "__type_traits/make_signed.h" }
-    module make_unsigned                      { private header "__type_traits/make_unsigned.h" }
-    module nat                                { private header "__type_traits/nat.h" }
-    module negation                           { private header "__type_traits/negation.h" }
-    module promote                            { private header "__type_traits/promote.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_cvref                       { private header "__type_traits/remove_cvref.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 type_list                          { private header "__type_traits/type_list.h" }
-    module underlying_type                    { private header "__type_traits/underlying_type.h" }
-    module void_t                             { private header "__type_traits/void_t.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 aligned_storage                     { private header "__type_traits/aligned_storage.h" }
+    module aligned_union                       { private header "__type_traits/aligned_union.h" }
+    module alignment_of                        { private header "__type_traits/alignment_of.h" }
+    module apply_cv                            { private header "__type_traits/apply_cv.h" }
+    module can_extract_key                     { private header "__type_traits/can_extract_key.h" }
+    module common_reference                    { private header "__type_traits/common_reference.h" }
+    module common_type                         { private header "__type_traits/common_type.h" }
+    module conditional                         { private header "__type_traits/conditional.h" }
+    module conjunction                         { private header "__type_traits/conjunction.h" }
+    module copy_cv                             { private header "__type_traits/copy_cv.h" }
+    module copy_cvref                          { private header "__type_traits/copy_cvref.h" }
+    module decay                               { private header "__type_traits/decay.h" }
+    module dependent_type                      { private header "__type_traits/dependent_type.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_char_like_type                   { private header "__type_traits/is_char_like_type.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_implicitly_default_constructible { private header "__type_traits/is_implicitly_default_constructible.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_convertible              { private header "__type_traits/is_nothrow_convertible.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_primary_template                 { private header "__type_traits/is_primary_template.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_signed_integer                   { private header "__type_traits/is_signed_integer.h" }
+    module is_standard_layout                  { private header "__type_traits/is_standard_layout.h" }
+    module is_swappable                        { private header "__type_traits/is_swappable.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_unsigned_integer                 { private header "__type_traits/is_unsigned_integer.h" }
+    module is_valid_expansion                  { private header "__type_traits/is_valid_expansion.h" }
+    module is_void                             { private header "__type_traits/is_void.h" }
+    module is_volatile                         { private header "__type_traits/is_volatile.h" }
+    module lazy                                { private header "__type_traits/lazy.h" }
+    module make_32_64_or_128_bit               { private header "__type_traits/make_32_64_or_128_bit.h" }
+    module make_const_lvalue_ref               { private header "__type_traits/make_const_lvalue_ref.h" }
+    module make_signed                         { private header "__type_traits/make_signed.h" }
+    module make_unsigned                       { private header "__type_traits/make_unsigned.h" }
+    module maybe_const                         { private header "__type_traits/maybe_const.h" }
+    module nat                                 { private header "__type_traits/nat.h" }
+    module negation                            { private header "__type_traits/negation.h" }
+    module promote                             { private header "__type_traits/promote.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_const_ref                    { private header "__type_traits/remove_const_ref.h" }
+    module remove_cv                           { private header "__type_traits/remove_cv.h" }
+    module remove_cvref                        { private header "__type_traits/remove_cvref.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 result_of                           { private header "__type_traits/result_of.h" }
+    module type_identity                       { private header "__type_traits/type_identity.h" }
+    module type_list                           { private header "__type_traits/type_list.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 *
module utility {
     header "utility"
     export initializer_list
     export *
 
     module __utility {
       module as_const            { private header "__utility/as_const.h" }
       module auto_cast           { private header "__utility/auto_cast.h" }
       module cmp                 { private header "__utility/cmp.h" }
+      module convert_to_integral { private header "__utility/convert_to_integral.h" }
       module declval             { private header "__utility/declval.h" }
       module exchange            { private header "__utility/exchange.h" }
       module forward             { private header "__utility/forward.h" }
       module in_place            { private header "__utility/in_place.h" }
       module integer_sequence    { private header "__utility/integer_sequence.h" }
       module move                { private header "__utility/move.h" }
       module pair                { private header "__utility/pair.h" }
+      module pair_fwd            { private header "__fwd/pair.h" }
       module piecewise_construct { private header "__utility/piecewise_construct.h" }
       module priority_tag        { private header "__utility/priority_tag.h" }
       module rel_ops             { private header "__utility/rel_ops.h" }
       module swap                { private header "__utility/swap.h" }
       module to_underlying       { private header "__utility/to_underlying.h" }
       module transaction         { private header "__utility/transaction.h" }
       module unreachable         { private header "__utility/unreachable.h" }
     }

libcxx/include/tuple

 #include <__assert> // all public C++ headers provide the assertion handler
 #include <__compare/common_comparison_category.h>
 #include <__compare/synth_three_way.h>
 #include <__config>
 #include <__functional/unwrap_ref.h>
 #include <__memory/allocator_arg_t.h>
 #include <__memory/uses_allocator.h>
 #include <__tuple>
+#include <__type_traits/maybe_const.h>
 #include <__utility/forward.h>
 #include <__utility/integer_sequence.h>
 #include <__utility/move.h>
 #include <__utility/pair.h>
 #include <__utility/piecewise_construct.h>
 #include <__utility/swap.h>
 #include <cstddef>
 #include <type_traits>

libcxx/include/type_traits

template <class...>
         inline constexpr bool negation_v = negation<B>::value;           // C++17
 
 }
 
 */
 #include <__assert> // all public C++ headers provide the assertion handler
 #include <__config>
 #include <__functional/invoke.h>
+#include <__fwd/hash.h> // This is https://llvm.org/PR56938
 #include <__type_traits/add_const.h>
 #include <__type_traits/add_cv.h>
 #include <__type_traits/add_lvalue_reference.h>
 #include <__type_traits/add_pointer.h>
 #include <__type_traits/add_rvalue_reference.h>
 #include <__type_traits/add_volatile.h>
 #include <__type_traits/aligned_storage.h>
 #include <__type_traits/aligned_union.h>
 #include <__type_traits/alignment_of.h>
 #include <__type_traits/apply_cv.h>
+#include <__type_traits/can_extract_key.h>
 #include <__type_traits/common_reference.h>
 #include <__type_traits/common_type.h>
 #include <__type_traits/conditional.h>
 #include <__type_traits/conjunction.h>
 #include <__type_traits/decay.h>
+#include <__type_traits/dependent_type.h>
 #include <__type_traits/disjunction.h>
 #include <__type_traits/enable_if.h>
 #include <__type_traits/extent.h>
 #include <__type_traits/has_unique_object_representation.h>
 #include <__type_traits/has_virtual_destructor.h>
 #include <__type_traits/integral_constant.h>
 #include <__type_traits/is_abstract.h>
 #include <__type_traits/is_aggregate.h>
 #include <__type_traits/is_arithmetic.h>
 #include <__type_traits/is_array.h>
 #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_char_like_type.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_implicitly_default_constructible.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_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_swappable.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/make_const_lvalue_ref.h>
 #include <__type_traits/make_signed.h>
 #include <__type_traits/make_unsigned.h>
+#include <__type_traits/maybe_const.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_const_ref.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/result_of.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 <cstdint>
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _T1, class _T2> struct _LIBCPP_TEMPLATE_VIS pair;
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS hash;
-
-// Member detector base
-
-template <class _Tp, bool>
-struct _LIBCPP_TEMPLATE_VIS __dependent_type : public _Tp {};
-
-// is_integral
-
-template <class _Tp>
-struct __unconstref {
-    typedef _LIBCPP_NODEBUG typename remove_const<typename remove_reference<_Tp>::type>::type type;
-};
-
-#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
-
-// result_of
-
-#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_TYPE_TRAITS)
-template <class _Callable> class _LIBCPP_DEPRECATED_IN_CXX17 result_of;
-
-template <class _Fp, class ..._Args>
-class _LIBCPP_TEMPLATE_VIS result_of<_Fp(_Args...)>
-    : public __invoke_of<_Fp, _Args...>
-{
-};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using result_of_t _LIBCPP_DEPRECATED_IN_CXX17 = typename result_of<_Tp>::type;
-#endif // _LIBCPP_STD_VER > 11
-#endif // _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_TYPE_TRAITS)
-
-// __swappable
-
-template <class _Tp> struct __is_swappable;
-template <class _Tp> struct __is_nothrow_swappable;
-
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp>
-using __swap_result_t = typename enable_if<is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value>::type;
-#else
-template <class>
-using __swap_result_t = void;
-#endif
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 __swap_result_t<_Tp>
-swap(_Tp& __x, _Tp& __y) _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value &&
-                                    is_nothrow_move_assignable<_Tp>::value);
-
-template<class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-typename enable_if<
-    __is_swappable<_Tp>::value
->::type
-swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value);
-
-namespace __detail
-{
-// ALL generic swap overloads MUST already have a declaration available at this point.
-
-template <class _Tp, class _Up = _Tp,
-          bool _NotVoid = !is_void<_Tp>::value && !is_void<_Up>::value>
-struct __swappable_with
-{
-    template <class _LHS, class _RHS>
-    static decltype(swap(declval<_LHS>(), declval<_RHS>()))
-    __test_swap(int);
-    template <class, class>
-    static __nat __test_swap(long);
-
-    // Extra parens are needed for the C++03 definition of decltype.
-    typedef decltype((__test_swap<_Tp, _Up>(0))) __swap1;
-    typedef decltype((__test_swap<_Up, _Tp>(0))) __swap2;
-
-    static const bool value = _IsNotSame<__swap1, __nat>::value
-                           && _IsNotSame<__swap2, __nat>::value;
-};
-
-template <class _Tp, class _Up>
-struct __swappable_with<_Tp, _Up,  false> : false_type {};
-
-template <class _Tp, class _Up = _Tp, bool _Swappable = __swappable_with<_Tp, _Up>::value>
-struct __nothrow_swappable_with {
-  static const bool value =
-#ifndef _LIBCPP_HAS_NO_NOEXCEPT
-      noexcept(swap(declval<_Tp>(), declval<_Up>()))
-  &&  noexcept(swap(declval<_Up>(), declval<_Tp>()));
-#else
-      false;
-#endif
-};
-
-template <class _Tp, class _Up>
-struct __nothrow_swappable_with<_Tp, _Up, false> : false_type {};
-
-} // namespace __detail
-
-template <class _Tp>
-struct __is_swappable
-    : public integral_constant<bool, __detail::__swappable_with<_Tp&>::value>
-{
-};
-
-template <class _Tp>
-struct __is_nothrow_swappable
-    : public integral_constant<bool, __detail::__nothrow_swappable_with<_Tp&>::value>
-{
-};
-
-#if _LIBCPP_STD_VER > 14
-
-template <class _Tp, class _Up>
-struct _LIBCPP_TEMPLATE_VIS is_swappable_with
-    : public integral_constant<bool, __detail::__swappable_with<_Tp, _Up>::value>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_swappable
-    : public conditional<
-        __is_referenceable<_Tp>::value,
-        is_swappable_with<
-            typename add_lvalue_reference<_Tp>::type,
-            typename add_lvalue_reference<_Tp>::type>,
-        false_type
-    >::type
-{
-};
-
-template <class _Tp, class _Up>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_swappable_with
-    : public integral_constant<bool, __detail::__nothrow_swappable_with<_Tp, _Up>::value>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_swappable
-    : public conditional<
-        __is_referenceable<_Tp>::value,
-        is_nothrow_swappable_with<
-            typename add_lvalue_reference<_Tp>::type,
-            typename add_lvalue_reference<_Tp>::type>,
-        false_type
-    >::type
-{
-};
-
-template <class _Tp, class _Up>
-inline constexpr bool is_swappable_with_v = is_swappable_with<_Tp, _Up>::value;
-
-template <class _Tp>
-inline constexpr bool is_swappable_v = is_swappable<_Tp>::value;
-
-template <class _Tp, class _Up>
-inline constexpr bool is_nothrow_swappable_with_v = is_nothrow_swappable_with<_Tp, _Up>::value;
-
-template <class _Tp>
-inline constexpr bool is_nothrow_swappable_v = is_nothrow_swappable<_Tp>::value;
-
-#endif // _LIBCPP_STD_VER > 14
-
-template <class _Tp, bool = is_enum<_Tp>::value>
-struct __sfinae_underlying_type
-{
-    typedef typename underlying_type<_Tp>::type type;
-    typedef decltype(((type)1) + 0) __promoted_type;
-};
-
-template <class _Tp>
-struct __sfinae_underlying_type<_Tp, false> {};
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __convert_to_integral(int __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-unsigned __convert_to_integral(unsigned __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-long __convert_to_integral(long __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-unsigned long __convert_to_integral(unsigned long __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-long long __convert_to_integral(long long __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-unsigned long long __convert_to_integral(unsigned long long __val) {return __val; }
-
-template<typename _Fp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if<is_floating_point<_Fp>::value, long long>::type
- __convert_to_integral(_Fp __val) { return __val; }
-
-#ifndef _LIBCPP_HAS_NO_INT128
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-__int128_t __convert_to_integral(__int128_t __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-__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; }
-
-// 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
-    : conditional<_IsSame<_RawValTy, _Key>::value, __extract_key_self_tag,
-                  __extract_key_fail_tag>::type {};
-
-template <class _Pair, class _Key, class _First, class _Second>
-struct __can_extract_key<_Pair, _Key, pair<_First, _Second> >
-    : conditional<_IsSame<typename remove_const<_First>::type, _Key>::value,
-                  __extract_key_first_tag, __extract_key_fail_tag>::type {};
-
-// __can_extract_map_key uses true_type/false_type instead of the tags.
-// It returns true if _Key != _ContainerValueTy (the container is a map not a set)
-// and _ValTy == _Key.
-template <class _ValTy, class _Key, class _ContainerValueTy,
-          class _RawValTy = typename __unconstref<_ValTy>::type>
-struct __can_extract_map_key
-    : integral_constant<bool, _IsSame<_RawValTy, _Key>::value> {};
-
-// This specialization returns __extract_key_fail_tag for non-map containers
-// because _Key == _ContainerValueTy
-template <class _ValTy, class _Key, class _RawValTy>
-struct __can_extract_map_key<_ValTy, _Key, _Key, _RawValTy>
-    : false_type {};
-
-template <class _CharT>
-using _IsCharLikeType = _And<is_standard_layout<_CharT>, is_trivial<_CharT> >;
-
-template<class _Tp>
-using __make_const_lvalue_ref = const typename remove_reference<_Tp>::type&;
-
-template<bool _Const, class _Tp>
-using __maybe_const = typename conditional<_Const, const _Tp, _Tp>::type;
-
-_LIBCPP_END_NAMESPACE_STD
-
 #endif // _LIBCPP_TYPE_TRAITS

libcxx/include/variant

 
 #include <__assert> // all public C++ headers provide the assertion handler
 #include <__availability>
 #include <__config>
 #include <__functional/hash.h>
 #include <__functional/operations.h>
 #include <__functional/unary_function.h>
 #include <__tuple>
+#include <__type_traits/dependent_type.h>
 #include <__utility/forward.h>
 #include <__utility/in_place.h>
 #include <__utility/move.h>
 #include <__utility/swap.h>
 #include <__variant/monostate.h>
 #include <exception>
 #include <initializer_list>
 #include <limits>

libcxx/test/libcxx/private_headers.verify.cpp

 #include <__functional/pointer_to_binary_function.h> // expected-error@*:* {{use of private header from outside its module: '__functional/pointer_to_binary_function.h'}}
 #include <__functional/pointer_to_unary_function.h> // expected-error@*:* {{use of private header from outside its module: '__functional/pointer_to_unary_function.h'}}
 #include <__functional/ranges_operations.h> // expected-error@*:* {{use of private header from outside its module: '__functional/ranges_operations.h'}}
 #include <__functional/reference_wrapper.h> // expected-error@*:* {{use of private header from outside its module: '__functional/reference_wrapper.h'}}
 #include <__functional/unary_function.h> // expected-error@*:* {{use of private header from outside its module: '__functional/unary_function.h'}}
 #include <__functional/unary_negate.h> // expected-error@*:* {{use of private header from outside its module: '__functional/unary_negate.h'}}
 #include <__functional/unwrap_ref.h> // expected-error@*:* {{use of private header from outside its module: '__functional/unwrap_ref.h'}}
 #include <__functional/weak_result_type.h> // expected-error@*:* {{use of private header from outside its module: '__functional/weak_result_type.h'}}
+#include <__fwd/hash.h> // expected-error@*:* {{use of private header from outside its module: '__fwd/hash.h'}}
+#include <__fwd/pair.h> // expected-error@*:* {{use of private header from outside its module: '__fwd/pair.h'}}
 #include <__fwd/span.h> // expected-error@*:* {{use of private header from outside its module: '__fwd/span.h'}}
 #include <__fwd/string_view.h> // expected-error@*:* {{use of private header from outside its module: '__fwd/string_view.h'}}
 #include <__ios/fpos.h> // expected-error@*:* {{use of private header from outside its module: '__ios/fpos.h'}}
 #include <__iterator/access.h> // expected-error@*:* {{use of private header from outside its module: '__iterator/access.h'}}
 #include <__iterator/advance.h> // expected-error@*:* {{use of private header from outside its module: '__iterator/advance.h'}}
 #include <__iterator/back_insert_iterator.h> // expected-error@*:* {{use of private header from outside its module: '__iterator/back_insert_iterator.h'}}
 #include <__iterator/bounded_iter.h> // expected-error@*:* {{use of private header from outside its module: '__iterator/bounded_iter.h'}}
 #include <__iterator/common_iterator.h> // expected-error@*:* {{use of private header from outside its module: '__iterator/common_iterator.h'}}

 #include <__type_traits/add_lvalue_reference.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/add_lvalue_reference.h'}}
 #include <__type_traits/add_pointer.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/add_pointer.h'}}
 #include <__type_traits/add_rvalue_reference.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/add_rvalue_reference.h'}}
 #include <__type_traits/add_volatile.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/add_volatile.h'}}
 #include <__type_traits/aligned_storage.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/aligned_storage.h'}}
 #include <__type_traits/aligned_union.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/aligned_union.h'}}
 #include <__type_traits/alignment_of.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/alignment_of.h'}}
 #include <__type_traits/apply_cv.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/apply_cv.h'}}
+#include <__type_traits/can_extract_key.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/can_extract_key.h'}}
 #include <__type_traits/common_reference.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/common_reference.h'}}
 #include <__type_traits/common_type.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/common_type.h'}}
 #include <__type_traits/conditional.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/conditional.h'}}
 #include <__type_traits/conjunction.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/conjunction.h'}}
 #include <__type_traits/copy_cv.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/copy_cv.h'}}
 #include <__type_traits/copy_cvref.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/copy_cvref.h'}}
 #include <__type_traits/decay.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/decay.h'}}
+#include <__type_traits/dependent_type.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/dependent_type.h'}}
 #include <__type_traits/disjunction.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/disjunction.h'}}
 #include <__type_traits/enable_if.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/enable_if.h'}}
 #include <__type_traits/extent.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/extent.h'}}
 #include <__type_traits/has_unique_object_representation.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/has_unique_object_representation.h'}}
 #include <__type_traits/has_virtual_destructor.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/has_virtual_destructor.h'}}
 #include <__type_traits/integral_constant.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/integral_constant.h'}}
 #include <__type_traits/is_abstract.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_abstract.h'}}
 #include <__type_traits/is_aggregate.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_aggregate.h'}}
 #include <__type_traits/is_arithmetic.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_arithmetic.h'}}
 #include <__type_traits/is_array.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_array.h'}}
 #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_char_like_type.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_char_like_type.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_implicitly_default_constructible.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_implicitly_default_constructible.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_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_signed_integer.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_signed_integer.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_swappable.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_swappable.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_unsigned_integer.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_unsigned_integer.h'}}
 #include <__type_traits/is_valid_expansion.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/is_valid_expansion.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/lazy.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/lazy.h'}}
 #include <__type_traits/make_32_64_or_128_bit.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/make_32_64_or_128_bit.h'}}
+#include <__type_traits/make_const_lvalue_ref.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/make_const_lvalue_ref.h'}}
 #include <__type_traits/make_signed.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/make_signed.h'}}
 #include <__type_traits/make_unsigned.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/make_unsigned.h'}}
+#include <__type_traits/maybe_const.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/maybe_const.h'}}
 #include <__type_traits/nat.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/nat.h'}}
 #include <__type_traits/negation.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/negation.h'}}
 #include <__type_traits/promote.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/promote.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_const_ref.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/remove_const_ref.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_cvref.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/remove_cvref.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/result_of.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/result_of.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/type_list.h> // expected-error@*:* {{use of private header from outside its module: '__type_traits/type_list.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/convert_to_integral.h> // expected-error@*:* {{use of private header from outside its module: '__utility/convert_to_integral.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'}}
 #include <__utility/move.h> // expected-error@*:* {{use of private header from outside its module: '__utility/move.h'}}
 #include <__utility/pair.h> // expected-error@*:* {{use of private header from outside its module: '__utility/pair.h'}}
 #include <__utility/piecewise_construct.h> // expected-error@*:* {{use of private header from outside its module: '__utility/piecewise_construct.h'}}
 #include <__utility/priority_tag.h> // expected-error@*:* {{use of private header from outside its module: '__utility/priority_tag.h'}}
 #include <__utility/rel_ops.h> // expected-error@*:* {{use of private header from outside its module: '__utility/rel_ops.h'}}
 #include <__utility/swap.h> // expected-error@*:* {{use of private header from outside its module: '__utility/swap.h'}}
 #include <__utility/to_underlying.h> // expected-error@*:* {{use of private header from outside its module: '__utility/to_underlying.h'}}
 #include <__utility/transaction.h> // expected-error@*:* {{use of private header from outside its module: '__utility/transaction.h'}}
 #include <__utility/unreachable.h> // expected-error@*:* {{use of private header from outside its module: '__utility/unreachable.h'}}
 #include <__variant/monostate.h> // expected-error@*:* {{use of private header from outside its module: '__variant/monostate.h'}}
 // GENERATED-MARKER

libcxx/test/libcxx/type_traits/convert_to_integral.pass.cpp

 
 // <type_traits>
 
 // __convert_to_integral(Tp)
 
 // Test that the __convert_to_integral functions properly converts Tp to the
 // correct type and value for integral, enum and user defined types.
 
+#include "test_macros.h"
+
+TEST_CLANG_DIAGNOSTIC_IGNORED("-Wprivate-header")
+#include <__utility/convert_to_integral.h>
 #include <limits>
 #include <type_traits>
 #include <cstdint>
 #include <cassert>
 
 #include "user_defined_integral.h"
 
-#include "test_macros.h"
-
 template <class T>
 struct EnumType
 {
   enum type : T {E_zero, E_one};
 };
 
 
 template <class From, class To>

libcxx/test/std/algorithms/alg.modifying.operations/alg.swap/swap_ranges.pass.cpp

 // template<ForwardIterator Iter1, ForwardIterator Iter2>
 //   requires HasSwap<Iter1::reference, Iter2::reference>
 //   Iter2
 //   swap_ranges(Iter1 first1, Iter1 last1, Iter2 first2);
 
 #include <algorithm>
 #include <cassert>
 #include <memory>
+#include <utility>
 
 #include "test_macros.h"
 #include "test_iterators.h"
 
 template<class Iter1, class Iter2>
 void
 test()
 {

libcxx/test/std/algorithms/ranges_robust_against_dangling.pass.cpp

 // <algorithm>
 //
 // Range algorithms should return `std::ranges::dangling` when given a dangling range.
 
 #include <algorithm>
 
 #include <array>
 #include <concepts>
+#include <functional>
 #include <iterator>
 #include <ranges>
 #include <random>
+#include <utility>
 
 #include "test_iterators.h"
 
 struct NonBorrowedRange {
   using Iter = int*;
   using Sent = sentinel_wrapper<Iter>;
 
   int* data_;