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-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef _LIBCPP___CONCEPTS_TOTALLY_ORDERED_H
10#define _LIBCPP___CONCEPTS_TOTALLY_ORDERED_H
11
12#include <__concepts/boolean_testable.h>
13#include <__concepts/equality_comparable.h>
14#include <__config>
15#include <__type_traits/common_reference.h>
16#include <__type_traits/make_const_lvalue_ref.h>
17
18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19#  pragma GCC system_header
20#endif
21
22_LIBCPP_BEGIN_NAMESPACE_STD
23
24#if _LIBCPP_STD_VER >= 20
25
26// [concept.totallyordered]
27
28template <class _Tp, class _Up>
29concept __partially_ordered_with = requires(__make_const_lvalue_ref<_Tp> __t, __make_const_lvalue_ref<_Up> __u) {
30  { __t < __u } -> __boolean_testable;
31  { __t > __u } -> __boolean_testable;
32  { __t <= __u } -> __boolean_testable;
33  { __t >= __u } -> __boolean_testable;
34  { __u < __t } -> __boolean_testable;
35  { __u > __t } -> __boolean_testable;
36  { __u <= __t } -> __boolean_testable;
37  { __u >= __t } -> __boolean_testable;
38};
39
40template <class _Tp>
41concept totally_ordered = equality_comparable<_Tp> && __partially_ordered_with<_Tp, _Tp>;
42
43// clang-format off
44template <class _Tp, class _Up>
45concept totally_ordered_with =
46    totally_ordered<_Tp> && totally_ordered<_Up> &&
47    equality_comparable_with<_Tp, _Up> &&
48    totally_ordered<
49        common_reference_t<
50            __make_const_lvalue_ref<_Tp>,
51            __make_const_lvalue_ref<_Up>>> &&
52    __partially_ordered_with<_Tp, _Up>;
53// clang-format on
54
55#endif // _LIBCPP_STD_VER >= 20
56
57_LIBCPP_END_NAMESPACE_STD
58
59#endif // _LIBCPP___CONCEPTS_TOTALLY_ORDERED_H
60