| //===----------------------------------------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is dual licensed under the MIT and the University of Illinois Open |
| // Source Licenses. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++98, c++03, c++11, c++14 |
| |
| // type_traits |
| |
| // is_nothrow_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&) noexcept {} |
| void swap(B&, A&) noexcept {} |
| |
| void swap(A&, C&) noexcept {} |
| void swap(C&, A&) {} |
| |
| struct M {}; |
| |
| void swap(M&&, M&&) noexcept {} |
| |
| } // namespace MyNS |
| |
| int main() |
| { |
| 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_nothrow_swappable_with<int, int>::value, ""); |
| static_assert(std::is_nothrow_swappable_with<int&, int&>::value, ""); |
| static_assert(std::is_nothrow_swappable_with<M, M>::value, ""); |
| static_assert(std::is_swappable_with<A&, A&>::value && |
| !std::is_nothrow_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_nothrow_swappable_with<A&, B&>::value, ""); |
| static_assert(!std::is_nothrow_swappable_with<A&, C&>::value && |
| std::is_swappable_with<A&, C&>::value, ""); |
| static_assert(!std::is_nothrow_swappable_with<D&, C&>::value, ""); |
| } |
| { |
| // test we guard against cv void inputs as required. |
| static_assert(!std::is_nothrow_swappable_with_v<void, int>, ""); |
| static_assert(!std::is_nothrow_swappable_with_v<int, void>, ""); |
| static_assert(!std::is_nothrow_swappable_with_v<const void, const volatile void>, ""); |
| |
| } |
| { |
| // test for presence of is_nothrow_swappable_with_v |
| static_assert(std::is_nothrow_swappable_with_v<int&, int&>, ""); |
| static_assert(!std::is_nothrow_swappable_with_v<int&&, int&&>, ""); |
| } |
| } |