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//===----------------------------------------------------------------------===//
//
// 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
}
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