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 
24 struct M {
lock_sharedM25     void lock_shared() {}
unlock_sharedM26     void unlock_shared() {}
27 };
28 
main(int,char **)29 int 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