| //===----------------------------------------------------------------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++03, c++11, c++14 |
| |
| // type_traits |
| |
| // is_swappable_with |
| |
| #include <type_traits> |
| #include <vector> |
| #include "test_macros.h" |
| |
| namespace MyNS { |
| |
| struct A { |
| A(A const&) = delete; |
| A& operator=(A const&) = delete; |
| }; |
| |
| struct B { |
| B(B const&) = delete; |
| B& operator=(B const&) = delete; |
| }; |
| |
| struct C {}; |
| struct D {}; |
| |
| void swap(A&, A&) {} |
| |
| void swap(A&, B&) {} |
| void swap(B&, A&) {} |
| |
| void swap(A&, C&) {} // missing swap(C, A) |
| void swap(D&, C&) {} |
| |
| struct M {}; |
| |
| void swap(M&&, M&&) {} |
| |
| } // namespace MyNS |
| |
| int main(int, char**) |
| { |
| using namespace MyNS; |
| { |
| // Test that is_swappable_with doesn't apply an lvalue reference |
| // to the type. Instead it is up to the user. |
| static_assert(!std::is_swappable_with<int, int>::value, ""); |
| static_assert(std::is_swappable_with<int&, int&>::value, ""); |
| static_assert(std::is_swappable_with<M, M>::value, ""); |
| static_assert(std::is_swappable_with<A&, A&>::value, ""); |
| } |
| { |
| // test that heterogeneous swap is allowed only if both 'swap(A, B)' and |
| // 'swap(B, A)' are valid. |
| static_assert(std::is_swappable_with<A&, B&>::value, ""); |
| static_assert(!std::is_swappable_with<A&, C&>::value, ""); |
| static_assert(!std::is_swappable_with<D&, C&>::value, ""); |
| } |
| { |
| // test that cv void is guarded against as required. |
| static_assert(!std::is_swappable_with_v<void, int>, ""); |
| static_assert(!std::is_swappable_with_v<int, void>, ""); |
| static_assert(!std::is_swappable_with_v<const void, const volatile void>, ""); |
| } |
| { |
| // test for presence of is_swappable_with_v |
| static_assert(std::is_swappable_with_v<int&, int&>, ""); |
| static_assert(!std::is_swappable_with_v<D&, C&>, ""); |
| } |
| |
| return 0; |
| } |