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// <mutex>
10
11// template <class Mutex> class unique_lock;
12
13// explicit operator bool() const noexcept;
14
15#include <cassert>
16#include <mutex>
17#include <type_traits>
18
19#include "checking_mutex.h"
20#include "test_macros.h"
21
22#if TEST_STD_VER >= 11
23static_assert(noexcept(static_cast<bool>(std::declval<std::unique_lock<checking_mutex>&>())), "");
24#endif
25
26int main(int, char**) {
27 static_assert(std::is_constructible<bool, std::unique_lock<checking_mutex> >::value, "");
28 static_assert(!std::is_convertible<std::unique_lock<checking_mutex>, bool>::value, "");
29
30 checking_mutex mux;
31 const std::unique_lock<checking_mutex> lk0; // Make sure `operator bool()` is `const`
32 assert(!static_cast<bool>(lk0));
33 std::unique_lock<checking_mutex> lk1(mux);
34 assert(static_cast<bool>(lk1));
35 lk1.unlock();
36 assert(!static_cast<bool>(lk1));
37
38 ASSERT_NOEXCEPT(static_cast<bool>(lk0));
39
40 return 0;
41}
42

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