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// UNSUPPORTED: libcpp-has-no-threads
11// UNSUPPORTED: c++98, c++03
12
13// <future>
14
15// class packaged_task<R(ArgTypes...)>
16
17// template <class R, class... ArgTypes>
18//   void
19//   swap(packaged_task<R(ArgTypes...)>& x, packaged_task<R(ArgTypes...)>& y);
20
21#include <future>
22#include <cassert>
23
24class A
25{
26    long data_;
27
28public:
29    explicit A(long i) : data_(i) {}
30
31    long operator()(long i, long j) const {return data_ + i + j;}
32};
33
34int main()
35{
36    {
37        std::packaged_task<double(int, char)> p0(A(5));
38        std::packaged_task<double(int, char)> p;
39        swap(p, p0);
40        assert(!p0.valid());
41        assert(p.valid());
42        std::future<double> f = p.get_future();
43        p(3, 'a');
44        assert(f.get() == 105.0);
45    }
46    {
47        std::packaged_task<double(int, char)> p0;
48        std::packaged_task<double(int, char)> p;
49        swap(p, p0);
50        assert(!p0.valid());
51        assert(!p.valid());
52    }
53}
54