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 // <memory>
11 
12 // weak_ptr
13 
14 // void swap(weak_ptr& r);
15 
16 #include <memory>
17 #include <cassert>
18 
19 struct A
20 {
21     static int count;
22 
23     A() {++count;}
24     A(const A&) {++count;}
25     ~A() {--count;}
26 };
27 
28 int A::count = 0;
29 
30 int main()
31 {
32     {
33         std::shared_ptr<A> p1(new A);
34         std::weak_ptr<A> w1(p1);
35         assert(w1.use_count() == 1);
36         w1.reset();
37         assert(w1.use_count() == 0);
38         assert(p1.use_count() == 1);
39     }
40     assert(A::count == 0);
41 }
42