1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
|
//===----------------------------------------------------------------------===//
//
// 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/common_reference.h>
#include <__type_traits/make_const_lvalue_ref.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 17
// [concept.equalitycomparable]
template<class _Tp, class _Up>
concept __weakly_equality_comparable_with =
requires(__make_const_lvalue_ref<_Tp> __t, __make_const_lvalue_ref<_Up> __u) {
{ __t == __u } -> __boolean_testable;
{ __t != __u } -> __boolean_testable;
{ __u == __t } -> __boolean_testable;
{ __u != __t } -> __boolean_testable;
};
template<class _Tp>
concept equality_comparable = __weakly_equality_comparable_with<_Tp, _Tp>;
template<class _Tp, class _Up>
concept equality_comparable_with =
equality_comparable<_Tp> && equality_comparable<_Up> &&
common_reference_with<__make_const_lvalue_ref<_Tp>, __make_const_lvalue_ref<_Up>> &&
equality_comparable<
common_reference_t<
__make_const_lvalue_ref<_Tp>,
__make_const_lvalue_ref<_Up>>> &&
__weakly_equality_comparable_with<_Tp, _Up>;
#endif // _LIBCPP_STD_VER > 17
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___CONCEPTS_EQUALITY_COMPARABLE_H
|
