| //===----------------------------------------------------------------------===// |
| // |
| // 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++03 |
| |
| // <functional> |
| // |
| // reference_wrapper |
| // |
| // template <class U> |
| // reference_wrapper(U&&) noexcept(see below); |
| |
| #include <functional> |
| #include <cassert> |
| |
| #include "test_macros.h" |
| |
| struct convertible_to_int_ref { |
| int val = 0; |
| operator int&() { return val; } |
| operator int const&() const { return val; } |
| }; |
| |
| template <bool IsNothrow> |
| struct nothrow_convertible { |
| int val = 0; |
| operator int&() noexcept(IsNothrow) { return val; } |
| }; |
| |
| struct convertible_from_int { |
| convertible_from_int(int) {} |
| }; |
| |
| void meow(std::reference_wrapper<int>) {} |
| void meow(convertible_from_int) {} |
| |
| int gi; |
| std::reference_wrapper<int> purr() { return gi; }; |
| |
| template <class T> |
| void |
| test(T& t) |
| { |
| std::reference_wrapper<T> r(t); |
| assert(&r.get() == &t); |
| } |
| |
| void f() {} |
| |
| int main(int, char**) |
| { |
| convertible_to_int_ref convi; |
| test(convi); |
| convertible_to_int_ref const convic; |
| test(convic); |
| |
| { |
| using Ref = std::reference_wrapper<int>; |
| static_assert((std::is_nothrow_constructible<Ref, nothrow_convertible<true>>::value), ""); |
| static_assert((!std::is_nothrow_constructible<Ref, nothrow_convertible<false>>::value), ""); |
| } |
| |
| { |
| meow(0); |
| (true) ? purr() : 0; |
| } |
| |
| #if TEST_STD_VER >= 17 |
| { |
| int i = 0; |
| std::reference_wrapper ri(i); |
| static_assert((std::is_same<decltype(ri), std::reference_wrapper<int>>::value), "" ); |
| const int j = 0; |
| std::reference_wrapper rj(j); |
| static_assert((std::is_same<decltype(rj), std::reference_wrapper<const int>>::value), "" ); |
| } |
| #endif |
| |
| return 0; |
| } |