|  | //===----------------------------------------------------------------------===// | 
|  | // | 
|  | // 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, c++11, c++14, c++17 | 
|  |  | 
|  | // <atomic> | 
|  |  | 
|  | // explicit atomic_ref(T&); | 
|  |  | 
|  | #include <atomic> | 
|  | #include <type_traits> | 
|  |  | 
|  | #include "atomic_helpers.h" | 
|  | #include "test_macros.h" | 
|  |  | 
|  | template <typename T> | 
|  | struct TestCtor { | 
|  | void operator()() const { | 
|  | // check that the constructor is explicit | 
|  | static_assert(!std::is_convertible_v<T, std::atomic_ref<T>>); | 
|  | static_assert(std::is_constructible_v<std::atomic_ref<T>, T&>); | 
|  |  | 
|  | T x(T(0)); | 
|  | std::atomic_ref<T> a(x); | 
|  | (void)a; | 
|  | } | 
|  | }; | 
|  |  | 
|  | int main(int, char**) { | 
|  | TestEachAtomicType<TestCtor>()(); | 
|  | return 0; | 
|  | } |