| //===----------------------------------------------------------------------===// |
| // |
| // 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 |
| |
| // test forward |
| |
| #include <utility> |
| #include <type_traits> |
| #include <cassert> |
| |
| #include "test_macros.h" |
| |
| struct A |
| { |
| }; |
| |
| A source() noexcept {return A();} |
| const A csource() noexcept {return A();} |
| |
| |
| constexpr bool test_constexpr_forward() { |
| #if TEST_STD_VER > 11 |
| 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; |
| #else |
| return true; |
| #endif |
| } |
| |
| int main() |
| { |
| 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, ""); |
| static_assert(noexcept(std::forward<A&>(a)), ""); |
| static_assert(noexcept(std::forward<A>(a)), ""); |
| static_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, ""); |
| static_assert(noexcept(std::forward<const A&>(a)), ""); |
| static_assert(noexcept(std::forward<const A>(a)), ""); |
| static_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, ""); |
| static_assert(noexcept(std::forward<const A&>(ca)), ""); |
| static_assert(noexcept(std::forward<const A>(ca)), ""); |
| static_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 |
| } |