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//===----------------------------------------------------------------------===//
//
// 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_THREE_WAY_COMPARABLE_H
#define _LIBCPP___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>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 17
template<class _Tp, class _Cat>
concept __compares_as =
same_as<common_comparison_category_t<_Tp, _Cat>, _Cat>;
template<class _Tp, class _Cat = partial_ordering>
concept three_way_comparable =
__weakly_equality_comparable_with<_Tp, _Tp> &&
__partially_ordered_with<_Tp, _Tp> &&
requires(__make_const_lvalue_ref<_Tp> __a, __make_const_lvalue_ref<_Tp> __b) {
{ __a <=> __b } -> __compares_as<_Cat>;
};
template<class _Tp, class _Up, class _Cat = partial_ordering>
concept three_way_comparable_with =
three_way_comparable<_Tp, _Cat> &&
three_way_comparable<_Up, _Cat> &&
common_reference_with<__make_const_lvalue_ref<_Tp>, __make_const_lvalue_ref<_Up>> &&
three_way_comparable<common_reference_t<__make_const_lvalue_ref<_Tp>, __make_const_lvalue_ref<_Up>>, _Cat> &&
__weakly_equality_comparable_with<_Tp, _Up> &&
__partially_ordered_with<_Tp, _Up> &&
requires(__make_const_lvalue_ref<_Tp> __t, __make_const_lvalue_ref<_Up> __u) {
{ __t <=> __u } -> __compares_as<_Cat>;
{ __u <=> __t } -> __compares_as<_Cat>;
};
#endif // _LIBCPP_STD_VER > 17
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___COMPARE_THREE_WAY_COMPARABLE_H
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