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 // shared_lock(mutex_type& m, defer_lock_t);
17 
18 #include <shared_mutex>
19 #include <cassert>
20 
main()21 int main()
22 {
23 #if _LIBCPP_STD_VER > 11
24     std::shared_timed_mutex m;
25     std::shared_lock<std::shared_timed_mutex> lk(m, std::defer_lock);
26     assert(lk.mutex() == &m);
27     assert(lk.owns_lock() == false);
28 #endif  // _LIBCPP_STD_VER > 11
29 }
30