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>
16 
17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18 #  pragma GCC system_header
19 #endif
20 
21 _LIBCPP_BEGIN_NAMESPACE_STD
22 
23 #if _LIBCPP_STD_VER > 17
24 
25 // [concept.totallyordered]
26 
27 template<class _Tp, class _Up>
28 concept __partially_ordered_with =
29   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 template<class _Tp, class _Up>
44 concept totally_ordered_with =
45   totally_ordered<_Tp> && totally_ordered<_Up> &&
46   equality_comparable_with<_Tp, _Up> &&
47   totally_ordered<
48     common_reference_t<
49       __make_const_lvalue_ref<_Tp>,
50       __make_const_lvalue_ref<_Up>>> &&
51   __partially_ordered_with<_Tp, _Up>;
52 
53 #endif // _LIBCPP_STD_VER > 17
54 
55 _LIBCPP_END_NAMESPACE_STD
56 
57 #endif // _LIBCPP___CONCEPTS_TOTALLY_ORDERED_H
58