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// <future>
11
12// class packaged_task<R(ArgTypes...)>
13
14// template <class R, class... ArgTypes>
15//   void
16//   swap(packaged_task<R(ArgTypes...)>& x, packaged_task<R(ArgTypes...)>& y);
17
18#include <future>
19#include <cassert>
20
21class A
22{
23    long data_;
24
25public:
26    explicit A(long i) : data_(i) {}
27
28    long operator()(long i, long j) const {return data_ + i + j;}
29};
30
31int main()
32{
33    {
34        std::packaged_task<double(int, char)> p0(A(5));
35        std::packaged_task<double(int, char)> p;
36        swap(p, p0);
37        assert(!p0.valid());
38        assert(p.valid());
39        std::future<double> f = p.get_future();
40        p(3, 'a');
41        assert(f.get() == 105.0);
42    }
43    {
44        std::packaged_task<double(int, char)> p0;
45        std::packaged_task<double(int, char)> p;
46        swap(p, p0);
47        assert(!p0.valid());
48        assert(!p.valid());
49    }
50}
51