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 // <shared_mutex>
11 
12 // template <class Mutex> class shared_lock;
13 
14 // explicit operator bool() const noexcept;
15 
16 #include <shared_mutex>
17 #include <cassert>
18 
19 #if _LIBCPP_STD_VER > 11
20 
21 std::shared_timed_mutex m;
22 
23 #endif  // _LIBCPP_STD_VER > 11
24 
main()25 int main()
26 {
27 #if _LIBCPP_STD_VER > 11
28     std::shared_lock<std::shared_timed_mutex> lk0;
29     assert(static_cast<bool>(lk0) == false);
30     std::shared_lock<std::shared_timed_mutex> lk1(m);
31     assert(static_cast<bool>(lk1) == true);
32     lk1.unlock();
33     assert(static_cast<bool>(lk1) == false);
34     static_assert(noexcept(static_cast<bool>(lk0)), "explicit operator bool() must be noexcept");
35 #endif  // _LIBCPP_STD_VER > 11
36 }
37