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: no-threads
10 // UNSUPPORTED: c++03
11 
12 // <future>
13 
14 // class packaged_task<R(ArgTypes...)>
15 
16 // template <class R, class... ArgTypes>
17 //   void
18 //   swap(packaged_task<R(ArgTypes...)>& x, packaged_task<R(ArgTypes...)>& y);
19 
20 #include <future>
21 #include <cassert>
22 
23 #include "test_macros.h"
24 
25 class A
26 {
27     long data_;
28 
29 public:
30     explicit A(long i) : data_(i) {}
31 
32     long operator()(long i, long j) const {return data_ + i + j;}
33 };
34 
35 int main(int, char**)
36 {
37     {
38         std::packaged_task<double(int, char)> p0(A(5));
39         std::packaged_task<double(int, char)> p;
40         swap(p, p0);
41         assert(!p0.valid());
42         assert(p.valid());
43         std::future<double> f = p.get_future();
44         p(3, 97);
45         assert(f.get() == 105.0);
46     }
47     {
48         std::packaged_task<double(int, char)> p0;
49         std::packaged_task<double(int, char)> p;
50         swap(p, p0);
51         assert(!p0.valid());
52         assert(!p.valid());
53     }
54 
55   return 0;
56 }
57