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-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// UNSUPPORTED: no-threads
10// UNSUPPORTED: c++03, c++11
11
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

source code of libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/op_bool.pass.cpp