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 // unique_lock(mutex_type& m, defer_lock_t);
14 
15 #include <cassert>
16 #include <memory>
17 #include <mutex>
18 #include <type_traits>
19 
20 #include "checking_mutex.h"
21 #include "test_macros.h"
22 
23 #if TEST_STD_VER >= 11
24 static_assert(
25     std::is_nothrow_constructible<std::unique_lock<checking_mutex>, checking_mutex&, std::defer_lock_t>::value, "");
26 #endif
27 
28 int main(int, char**) {
29   checking_mutex m;
30   std::unique_lock<checking_mutex> lk(m, std::defer_lock_t());
31   assert(m.last_try == checking_mutex::none);
32   assert(lk.mutex() == std::addressof(m));
33   assert(lk.owns_lock() == false);
34 
35   return 0;
36 }
37