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// <mutex>
11
12// template <class Mutex> class unique_lock;
13
14// void swap(unique_lock& u);
15
16#include <mutex>
17#include <cassert>
18
19struct mutex
20{
21    void lock() {}
22    void unlock() {}
23};
24
25mutex m;
26
27int main()
28{
29    std::unique_lock<mutex> lk1(m);
30    std::unique_lock<mutex> lk2;
31    lk1.swap(lk2);
32    assert(lk1.mutex() == nullptr);
33    assert(lk1.owns_lock() == false);
34    assert(lk2.mutex() == &m);
35    assert(lk2.owns_lock() == true);
36}
37