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 // mutex_type *mutex() const;
14 
15 #include <cassert>
16 #include <memory>
17 #include <mutex>
18 
19 #include "checking_mutex.h"
20 #include "test_macros.h"
21 
22 #if TEST_STD_VER >= 11
23 static_assert(noexcept(std::declval<std::unique_lock<checking_mutex>&>().mutex()), "");
24 #endif
25 
26 int main(int, char**) {
27   checking_mutex mux;
28   const std::unique_lock<checking_mutex> lock0; // Make sure `mutex()` is `const`
29   static_assert(std::is_same<decltype(lock0.mutex()), checking_mutex*>::value, "");
30   assert(lock0.mutex() == nullptr);
31   std::unique_lock<checking_mutex> lock1(mux);
32   assert(lock1.mutex() == std::addressof(mux));
33   lock1.unlock();
34   assert(lock1.mutex() == std::addressof(mux));
35 
36   return 0;
37 }
38