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 | // UNSUPPORTED: c++03, c++11, c++14, c++17 |
10 | |
11 | // template<class F, class... Args> |
12 | // concept strict_weak_order; |
13 | |
14 | #include <concepts> |
15 | |
16 | struct S1 {}; |
17 | struct S2 {}; |
18 | |
19 | struct R { |
20 | bool operator()(S1, S1) const; |
21 | bool operator()(S1, S2) const; |
22 | bool operator()(S2, S1) const; |
23 | bool operator()(S2, S2) const; |
24 | }; |
25 | |
26 | // clang-format off |
27 | template<class F, class T, class U> |
28 | requires std::relation<F, T, U> |
29 | constexpr bool check_strict_weak_order_subsumes_relation() { |
30 | return false; |
31 | } |
32 | |
33 | template<class F, class T, class U> |
34 | requires std::strict_weak_order<F, T, U> && true |
35 | constexpr bool check_strict_weak_order_subsumes_relation() { |
36 | return true; |
37 | } |
38 | // clang-format on |
39 | |
40 | static_assert(check_strict_weak_order_subsumes_relation<int (*)(int, int), int, int>()); |
41 | static_assert(check_strict_weak_order_subsumes_relation<int (*)(int, double), int, double>()); |
42 | static_assert(check_strict_weak_order_subsumes_relation<R, S1, S1>()); |
43 | static_assert(check_strict_weak_order_subsumes_relation<R, S1, S2>()); |
44 | |
45 | // clang-format off |
46 | template<class F, class T, class U> |
47 | requires std::relation<F, T, U> && true |
48 | constexpr bool check_relation_subsumes_strict_weak_order() { |
49 | return true; |
50 | } |
51 | |
52 | template<class F, class T, class U> |
53 | requires std::strict_weak_order<F, T, U> |
54 | constexpr bool check_relation_subsumes_strict_weak_order() { |
55 | return false; |
56 | } |
57 | // clang-format on |
58 | |
59 | static_assert(check_relation_subsumes_strict_weak_order<int (*)(int, int), int, int>()); |
60 | static_assert(check_relation_subsumes_strict_weak_order<int (*)(int, double), int, double>()); |
61 | static_assert(check_relation_subsumes_strict_weak_order<R, S1, S1>()); |
62 | static_assert(check_relation_subsumes_strict_weak_order<R, S1, S2>()); |
63 | |
64 | // clang-format off |
65 | template<class F, class T, class U> |
66 | requires std::strict_weak_order<F, T, T> && std::strict_weak_order<F, U, U> |
67 | constexpr bool check_strict_weak_order_subsumes_itself() { |
68 | return false; |
69 | } |
70 | |
71 | template<class F, class T, class U> |
72 | requires std::strict_weak_order<F, T, U> |
73 | constexpr bool check_strict_weak_order_subsumes_itself() { |
74 | return true; |
75 | } |
76 | // clang-format on |
77 | |
78 | static_assert(check_strict_weak_order_subsumes_itself<int (*)(int, int), int, int>()); |
79 | static_assert(check_strict_weak_order_subsumes_itself<R, S1, S1>()); |
80 | |