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// shared_ptr
13
14// template<class Y> shared_ptr(shared_ptr<Y>&& r);
15
16#include <memory>
17#include <type_traits>
18#include <cassert>
19
20struct B
21{
22    static int count;
23
24    B() {++count;}
25    B(const B&) {++count;}
26    virtual ~B() {--count;}
27};
28
29int B::count = 0;
30
31struct A
32    : public B
33{
34    static int count;
35
36    A() {++count;}
37    A(const A&) {++count;}
38    ~A() {--count;}
39};
40
41int A::count = 0;
42
43struct C
44{
45    static int count;
46
47    C() {++count;}
48    C(const C&) {++count;}
49    virtual ~C() {--count;}
50};
51
52int C::count = 0;
53
54int main()
55{
56    static_assert(( std::is_convertible<std::shared_ptr<A>, std::shared_ptr<B> >::value), "");
57    static_assert((!std::is_convertible<std::shared_ptr<B>, std::shared_ptr<A> >::value), "");
58    static_assert((!std::is_convertible<std::shared_ptr<A>, std::shared_ptr<C> >::value), "");
59    {
60        std::shared_ptr<A> pA(new A);
61        assert(pA.use_count() == 1);
62        assert(B::count == 1);
63        assert(A::count == 1);
64        {
65            B* p = pA.get();
66            std::shared_ptr<B> pB(std::move(pA));
67            assert(B::count == 1);
68            assert(A::count == 1);
69#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
70            assert(pB.use_count() == 1);
71            assert(pA.use_count() == 0);
72#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
73            assert(pB.use_count() == 2);
74            assert(pA.use_count() == 2);
75#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
76            assert(p == pB.get());
77        }
78#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
79        assert(pA.use_count() == 0);
80        assert(B::count == 0);
81        assert(A::count == 0);
82#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
83        assert(pA.use_count() == 1);
84        assert(B::count == 1);
85        assert(A::count == 1);
86#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
87    }
88    assert(B::count == 0);
89    assert(A::count == 0);
90    {
91        std::shared_ptr<A> pA;
92        assert(pA.use_count() == 0);
93        assert(B::count == 0);
94        assert(A::count == 0);
95        {
96            std::shared_ptr<B> pB(pA);
97            assert(B::count == 0);
98            assert(A::count == 0);
99            assert(pB.use_count() == 0);
100            assert(pA.use_count() == 0);
101            assert(pA.get() == pB.get());
102        }
103        assert(pA.use_count() == 0);
104        assert(B::count == 0);
105        assert(A::count == 0);
106    }
107    assert(B::count == 0);
108    assert(A::count == 0);
109}
110