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 // UNSUPPORTED: libcpp-has-no-threads
10 
11 // <mutex>
12 
13 // template <class Mutex> class unique_lock;
14 
15 // template <class Mutex>
16 //   void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y);
17 
18 #include <mutex>
19 #include <cassert>
20 
21 #include "test_macros.h"
22 
23 struct mutex
24 {
25     void lock() {}
26     void unlock() {}
27 };
28 
29 mutex m;
30 
31 int main(int, char**)
32 {
33     std::unique_lock<mutex> lk1(m);
34     std::unique_lock<mutex> lk2;
35     swap(lk1, lk2);
36     assert(lk1.mutex() == nullptr);
37     assert(lk1.owns_lock() == false);
38     assert(lk2.mutex() == &m);
39     assert(lk2.owns_lock() == true);
40 
41   return 0;
42 }
43