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1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___COMPARE_THREE_WAY_COMPARABLE_H10#define _LIBCPP___COMPARE_THREE_WAY_COMPARABLE_H11 12#include <__compare/common_comparison_category.h>13#include <__compare/ordering.h>14#include <__concepts/common_reference_with.h>15#include <__concepts/equality_comparable.h>16#include <__concepts/same_as.h>17#include <__concepts/totally_ordered.h>18#include <__config>19#include <__type_traits/common_reference.h>20#include <__type_traits/make_const_lvalue_ref.h>21 22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)23# pragma GCC system_header24#endif25 26_LIBCPP_BEGIN_NAMESPACE_STD27 28#if _LIBCPP_STD_VER >= 2029 30template <class _Tp, class _Cat>31concept __compares_as = same_as<common_comparison_category_t<_Tp, _Cat>, _Cat>;32 33template <class _Tp, class _Cat = partial_ordering>34concept three_way_comparable =35 __weakly_equality_comparable_with<_Tp, _Tp> && __partially_ordered_with<_Tp, _Tp> &&36 requires(__make_const_lvalue_ref<_Tp> __a, __make_const_lvalue_ref<_Tp> __b) {37 { __a <=> __b } -> __compares_as<_Cat>;38 };39 40template <class _Tp, class _Up, class _Cat = partial_ordering>41concept three_way_comparable_with =42 three_way_comparable<_Tp, _Cat> && three_way_comparable<_Up, _Cat> &&43 common_reference_with<__make_const_lvalue_ref<_Tp>, __make_const_lvalue_ref<_Up>> &&44 three_way_comparable<common_reference_t<__make_const_lvalue_ref<_Tp>, __make_const_lvalue_ref<_Up>>, _Cat> &&45 __weakly_equality_comparable_with<_Tp, _Up> && __partially_ordered_with<_Tp, _Up> &&46 requires(__make_const_lvalue_ref<_Tp> __t, __make_const_lvalue_ref<_Up> __u) {47 { __t <=> __u } -> __compares_as<_Cat>;48 { __u <=> __t } -> __compares_as<_Cat>;49 };50 51#endif // _LIBCPP_STD_VER >= 2052 53_LIBCPP_END_NAMESPACE_STD54 55#endif // _LIBCPP___COMPARE_THREE_WAY_COMPARABLE_H56