| 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 | |