45 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// UNSUPPORTED: no-threads10// UNSUPPORTED: c++03, c++1111 12// <shared_mutex>13 14// template <class Mutex> class shared_lock;15 16// explicit operator bool() const noexcept;17 18#include <shared_mutex>19#include <cassert>20#include <type_traits>21 22#include "test_macros.h"23 24struct M {25 void lock_shared() {}26 void unlock_shared() {}27};28 29int main(int, char**)30{31 static_assert(std::is_constructible<bool, std::shared_lock<M>>::value, "");32 static_assert(!std::is_convertible<std::shared_lock<M>, bool>::value, "");33 34 M m;35 std::shared_lock<M> lk0;36 assert(static_cast<bool>(lk0) == false);37 std::shared_lock<M> lk1(m);38 assert(static_cast<bool>(lk1) == true);39 lk1.unlock();40 assert(static_cast<bool>(lk1) == false);41 ASSERT_NOEXCEPT(static_cast<bool>(lk0));42 43 return 0;44}45