| 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 |
|---|
| 10 | |
|---|
| 11 | // type_traits |
|---|
| 12 | |
|---|
| 13 | // is_swappable_with |
|---|
| 14 | |
|---|
| 15 | #include <type_traits> |
|---|
| 16 | #include <vector> |
|---|
| 17 | #include "test_macros.h" |
|---|
| 18 | |
|---|
| 19 | namespace MyNS { |
|---|
| 20 | |
|---|
| 21 | struct A { |
|---|
| 22 | A(A const&) = delete; |
|---|
| 23 | A& operator=(A const&) = delete; |
|---|
| 24 | }; |
|---|
| 25 | |
|---|
| 26 | struct B { |
|---|
| 27 | B(B const&) = delete; |
|---|
| 28 | B& operator=(B const&) = delete; |
|---|
| 29 | }; |
|---|
| 30 | |
|---|
| 31 | struct C {}; |
|---|
| 32 | struct D {}; |
|---|
| 33 | |
|---|
| 34 | void swap(A&, A&) {} |
|---|
| 35 | |
|---|
| 36 | void swap(A&, B&) {} |
|---|
| 37 | void swap(B&, A&) {} |
|---|
| 38 | |
|---|
| 39 | void swap(A&, C&) {} // missing swap(C, A) |
|---|
| 40 | void swap(D&, C&) {} |
|---|
| 41 | |
|---|
| 42 | struct M {}; |
|---|
| 43 | |
|---|
| 44 | void swap(M&&, M&&) {} |
|---|
| 45 | |
|---|
| 46 | } // namespace MyNS |
|---|
| 47 | |
|---|
| 48 | int main(int, char**) |
|---|
| 49 | { |
|---|
| 50 | using namespace MyNS; |
|---|
| 51 | { |
|---|
| 52 | // Test that is_swappable_with doesn't apply an lvalue reference |
|---|
| 53 | // to the type. Instead it is up to the user. |
|---|
| 54 | static_assert(!std::is_swappable_with<int, int>::value, "" ); |
|---|
| 55 | static_assert(std::is_swappable_with<int&, int&>::value, "" ); |
|---|
| 56 | static_assert(std::is_swappable_with<M, M>::value, "" ); |
|---|
| 57 | static_assert(std::is_swappable_with<A&, A&>::value, "" ); |
|---|
| 58 | } |
|---|
| 59 | { |
|---|
| 60 | // test that heterogeneous swap is allowed only if both 'swap(A, B)' and |
|---|
| 61 | // 'swap(B, A)' are valid. |
|---|
| 62 | static_assert(std::is_swappable_with<A&, B&>::value, "" ); |
|---|
| 63 | static_assert(!std::is_swappable_with<A&, C&>::value, "" ); |
|---|
| 64 | static_assert(!std::is_swappable_with<D&, C&>::value, "" ); |
|---|
| 65 | } |
|---|
| 66 | { |
|---|
| 67 | // test that cv void is guarded against as required. |
|---|
| 68 | static_assert(!std::is_swappable_with_v<void, int>, "" ); |
|---|
| 69 | static_assert(!std::is_swappable_with_v<int, void>, "" ); |
|---|
| 70 | static_assert(!std::is_swappable_with_v<const void, const volatile void>, "" ); |
|---|
| 71 | } |
|---|
| 72 | { |
|---|
| 73 | // test for presence of is_swappable_with_v |
|---|
| 74 | static_assert(std::is_swappable_with_v<int&, int&>, "" ); |
|---|
| 75 | static_assert(!std::is_swappable_with_v<D&, C&>, "" ); |
|---|
| 76 | } |
|---|
| 77 | |
|---|
| 78 | return 0; |
|---|
| 79 | } |
|---|
| 80 | |
|---|
