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 
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 class A
24 {
25     long data_;
26 
27 public:
A(long i)28     explicit A(long i) : data_(i) {}
29 
operator ()(long i,long j) const30     long operator()(long i, long j) const {return data_ + i + j;}
31 };
32 
main()33 int main()
34 {
35     {
36         std::packaged_task<double(int, char)> p0(A(5));
37         std::packaged_task<double(int, char)> p;
38         swap(p, p0);
39         assert(!p0.valid());
40         assert(p.valid());
41         std::future<double> f = p.get_future();
42         p(3, 'a');
43         assert(f.get() == 105.0);
44     }
45     {
46         std::packaged_task<double(int, char)> p0;
47         std::packaged_task<double(int, char)> p;
48         swap(p, p0);
49         assert(!p0.valid());
50         assert(!p.valid());
51     }
52 }
53