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 
28 template <class _Tp, class _Up>
29 concept __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 
40 template <class _Tp>
41 concept totally_ordered = equality_comparable<_Tp> && __partially_ordered_with<_Tp, _Tp>;
42 
43 // clang-format off
44 template <class _Tp, class _Up>
45 concept 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