shared_ptr_Y.pass.cpp revision c52f43e72dfcea03037729649da84c23b3beb04a 
1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// <memory>
11
12// weak_ptr
13
14// template<class Y> weak_ptr(const 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::weak_ptr<B> >::value), "");
57    static_assert((!std::is_convertible<std::weak_ptr<B>, std::shared_ptr<A> >::value), "");
58    static_assert((!std::is_convertible<std::shared_ptr<A>, std::weak_ptr<C> >::value), "");
59    {
60        const 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            std::weak_ptr<B> pB(pA);
66            assert(B::count == 1);
67            assert(A::count == 1);
68            assert(pB.use_count() == 1);
69            assert(pA.use_count() == 1);
70        }
71        assert(pA.use_count() == 1);
72        assert(B::count == 1);
73        assert(A::count == 1);
74    }
75    assert(B::count == 0);
76    assert(A::count == 0);
77    {
78        std::shared_ptr<A> pA;
79        assert(pA.use_count() == 0);
80        assert(B::count == 0);
81        assert(A::count == 0);
82        {
83            std::weak_ptr<B> pB(pA);
84            assert(B::count == 0);
85            assert(A::count == 0);
86            assert(pB.use_count() == 0);
87            assert(pA.use_count() == 0);
88        }
89        assert(pA.use_count() == 0);
90        assert(B::count == 0);
91        assert(A::count == 0);
92    }
93    assert(B::count == 0);
94    assert(A::count == 0);
95}
96