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// template <class Mutex>17// void swap(shared_lock<Mutex>& x, shared_lock<Mutex>& y) noexcept;18 19#include <shared_mutex>20#include <cassert>21 22#include "test_macros.h"23 24struct mutex25{26 void lock_shared() {}27 void unlock_shared() {}28};29 30mutex m;31 32int main(int, char**)33{34 std::shared_lock<mutex> lk1(m);35 std::shared_lock<mutex> lk2;36 swap(lk1, lk2);37 assert(lk1.mutex() == nullptr);38 assert(lk1.owns_lock() == false);39 assert(lk2.mutex() == &m);40 assert(lk2.owns_lock() == true);41 static_assert(noexcept(swap(lk1, lk2)), "non-member swap must be noexcept");42 43 return 0;44}45