1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // UNSUPPORTED: libcpp-has-no-threads
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 
21 #if _LIBCPP_STD_VER > 11
22 
23 std::shared_timed_mutex m;
24 
25 #endif  // _LIBCPP_STD_VER > 11
26 
main()27 int main()
28 {
29 #if _LIBCPP_STD_VER > 11
30     std::shared_lock<std::shared_timed_mutex> lk0;
31     assert(static_cast<bool>(lk0) == false);
32     std::shared_lock<std::shared_timed_mutex> lk1(m);
33     assert(static_cast<bool>(lk1) == true);
34     lk1.unlock();
35     assert(static_cast<bool>(lk1) == false);
36     static_assert(noexcept(static_cast<bool>(lk0)), "explicit operator bool() must be noexcept");
37 #endif  // _LIBCPP_STD_VER > 11
38 }
39