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 // <thread>
12 
13 // class thread
14 
15 // void swap(thread& x, thread& y);
16 
17 #include <thread>
18 #include <new>
19 #include <cstdlib>
20 #include <cassert>
21 
22 class G
23 {
24     int alive_;
25 public:
26     static int n_alive;
27     static bool op_run;
28 
29     G() : alive_(1) {++n_alive;}
30     G(const G& g) : alive_(g.alive_) {++n_alive;}
31     ~G() {alive_ = 0; --n_alive;}
32 
33     void operator()()
34     {
35         assert(alive_ == 1);
36         assert(n_alive >= 1);
37         op_run = true;
38     }
39 };
40 
41 int G::n_alive = 0;
42 bool G::op_run = false;
43 
44 int main(int, char**)
45 {
46     {
47         G g;
48         std::thread t0(g);
49         std::thread::id id0 = t0.get_id();
50         std::thread t1;
51         std::thread::id id1 = t1.get_id();
52         swap(t0, t1);
53         assert(t0.get_id() == id1);
54         assert(t1.get_id() == id0);
55         t1.join();
56     }
57 
58   return 0;
59 }
60