| //===----------------------------------------------------------------------===// |
| // |
| // 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++98, c++03 |
| |
| // test forward |
| |
| #include <utility> |
| #include <type_traits> |
| #include <cassert> |
| |
| #include "test_macros.h" |
| |
| struct A |
| { |
| }; |
| |
| A source() TEST_NOEXCEPT {return A();} |
| const A csource() TEST_NOEXCEPT {return A();} |
| |
| |
| #if TEST_STD_VER > 11 |
| constexpr bool test_constexpr_forward() { |
| int x = 42; |
| const int cx = 101; |
| return std::forward<int&>(x) == 42 |
| && std::forward<int>(x) == 42 |
| && std::forward<const int&>(x) == 42 |
| && std::forward<const int>(x) == 42 |
| && std::forward<int&&>(x) == 42 |
| && std::forward<const int&&>(x) == 42 |
| && std::forward<const int&>(cx) == 101 |
| && std::forward<const int>(cx) == 101; |
| } |
| #endif |
| |
| int main(int, char**) |
| { |
| A a; |
| const A ca = A(); |
| |
| ((void)a); // Prevent unused warning |
| ((void)ca); // Prevent unused warning |
| |
| static_assert(std::is_same<decltype(std::forward<A&>(a)), A&>::value, ""); |
| static_assert(std::is_same<decltype(std::forward<A>(a)), A&&>::value, ""); |
| static_assert(std::is_same<decltype(std::forward<A>(source())), A&&>::value, ""); |
| ASSERT_NOEXCEPT(std::forward<A&>(a)); |
| ASSERT_NOEXCEPT(std::forward<A>(a)); |
| ASSERT_NOEXCEPT(std::forward<A>(source())); |
| |
| static_assert(std::is_same<decltype(std::forward<const A&>(a)), const A&>::value, ""); |
| static_assert(std::is_same<decltype(std::forward<const A>(a)), const A&&>::value, ""); |
| static_assert(std::is_same<decltype(std::forward<const A>(source())), const A&&>::value, ""); |
| ASSERT_NOEXCEPT(std::forward<const A&>(a)); |
| ASSERT_NOEXCEPT(std::forward<const A>(a)); |
| ASSERT_NOEXCEPT(std::forward<const A>(source())); |
| |
| static_assert(std::is_same<decltype(std::forward<const A&>(ca)), const A&>::value, ""); |
| static_assert(std::is_same<decltype(std::forward<const A>(ca)), const A&&>::value, ""); |
| static_assert(std::is_same<decltype(std::forward<const A>(csource())), const A&&>::value, ""); |
| ASSERT_NOEXCEPT(std::forward<const A&>(ca)); |
| ASSERT_NOEXCEPT(std::forward<const A>(ca)); |
| ASSERT_NOEXCEPT(std::forward<const A>(csource())); |
| |
| #if TEST_STD_VER > 11 |
| { |
| constexpr int i2 = std::forward<int>(42); |
| static_assert(std::forward<int>(42) == 42, ""); |
| static_assert(std::forward<const int&>(i2) == 42, ""); |
| static_assert(test_constexpr_forward(), ""); |
| } |
| #endif |
| #if TEST_STD_VER == 11 && defined(_LIBCPP_VERSION) |
| // Test that std::forward is constexpr in C++11. This is an extension |
| // provided by both libc++ and libstdc++. |
| { |
| constexpr int i2 = std::forward<int>(42); |
| static_assert(std::forward<int>(42) == 42, "" ); |
| static_assert(std::forward<const int&>(i2) == 42, ""); |
| } |
| #endif |
| |
| return 0; |
| } |