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 // template<class U> bool owner_before(const shared_ptr<U>& b);
15 
16 #include <memory>
17 #include <cassert>
18 
19 int main()
20 {
21     const std::shared_ptr<int> p1(new int);
22     const std::shared_ptr<int> p2 = p1;
23     const std::shared_ptr<int> p3(new int);
24     const std::weak_ptr<int> w1(p1);
25     const std::weak_ptr<int> w2(p2);
26     const std::weak_ptr<int> w3(p3);
27     assert(!w1.owner_before(p2));
28     assert(!w2.owner_before(p1));
29     assert(w1.owner_before(p3) || w3.owner_before(p1));
30     assert(w3.owner_before(p1) == w3.owner_before(p2));
31 }
32