blob: a5ee5eb6fb67d647fe7dd16276fce60ee6c10654 (
plain) (
blame)
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
|
//===----------------------------------------------------------------------===//
//
// 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_SYNTH_THREE_WAY_H
#define _LIBCPP___COMPARE_SYNTH_THREE_WAY_H
#include <__compare/ordering.h>
#include <__compare/three_way_comparable.h>
#include <__concepts/boolean_testable.h>
#include <__config>
#include <__utility/declval.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
// [expos.only.func]
_LIBCPP_HIDE_FROM_ABI inline constexpr auto __synth_three_way =
[]<class _Tp, class _Up>(const _Tp& __t, const _Up& __u)
requires requires {
{ __t < __u } -> __boolean_testable;
{ __u < __t } -> __boolean_testable;
}
{
if constexpr (three_way_comparable_with<_Tp, _Up>) {
return __t <=> __u;
} else {
if (__t < __u) return weak_ordering::less;
if (__u < __t) return weak_ordering::greater;
return weak_ordering::equivalent;
}
};
template <class _Tp, class _Up = _Tp>
using __synth_three_way_result = decltype(std::__synth_three_way(declval<_Tp&>(), declval<_Up&>()));
#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___COMPARE_SYNTH_THREE_WAY_H
|