1c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant//===----------------------------------------------------------------------===//
2c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant//
3c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant//                     The LLVM Compiler Infrastructure
4c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant//
5b64f8b07c104c6cc986570ac8ee0ed16a9f23976Howard Hinnant// This file is dual licensed under the MIT and the University of Illinois Open
6b64f8b07c104c6cc986570ac8ee0ed16a9f23976Howard Hinnant// Source Licenses. See LICENSE.TXT for details.
7c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant//
8c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant//===----------------------------------------------------------------------===//
9c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
10c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant// <memory>
11c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
12c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant// weak_ptr
13c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
14c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant// template<class Y> weak_ptr& operator=(const shared_ptr<Y>& r);
15c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
16c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant#include <memory>
17c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant#include <type_traits>
18c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant#include <cassert>
19c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
20c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnantstruct B
21c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant{
22c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    static int count;
23c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
24c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    B() {++count;}
25c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    B(const B&) {++count;}
26c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    virtual ~B() {--count;}
27c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant};
28c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
29c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnantint B::count = 0;
30c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
31c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnantstruct A
32c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    : public B
33c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant{
34c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    static int count;
35c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
36c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    A() {++count;}
37c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    A(const A&) {++count;}
38c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    ~A() {--count;}
39c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant};
40c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
41c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnantint A::count = 0;
42c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant
43c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnantint main()
44c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant{
45c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    {
46c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant        const std::shared_ptr<A> pA(new A);
47c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant        {
48c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant            std::weak_ptr<B> pB;
49c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant            pB = pA;
50c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant            assert(B::count == 1);
51c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant            assert(A::count == 1);
52c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant            assert(pB.use_count() == 1);
53c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant            assert(pA.use_count() == 1);
54c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant        }
55c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant        assert(pA.use_count() == 1);
56c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant        assert(B::count == 1);
57c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant        assert(A::count == 1);
58c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    }
59c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    assert(B::count == 0);
60c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant    assert(A::count == 0);
61c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant}
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