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 // shared_ptr& operator=(const shared_ptr& r);
15 
16 #include <memory>
17 #include <type_traits>
18 #include <cassert>
19 
20 struct B
21 {
22     static int count;
23 
BB24     B() {++count;}
BB25     B(const B&) {++count;}
~BB26     virtual ~B() {--count;}
27 };
28 
29 int B::count = 0;
30 
31 struct A
32     : public B
33 {
34     static int count;
35 
AA36     A() {++count;}
AA37     A(const A&) {++count;}
~AA38     ~A() {--count;}
39 };
40 
41 int A::count = 0;
42 
main()43 int main()
44 {
45     {
46         const std::shared_ptr<A> pA(new A);
47         A* ptrA = pA.get();
48         {
49             std::shared_ptr<A> pB(new A);
50             pB = pA;
51             assert(B::count == 1);
52             assert(A::count == 1);
53             assert(pB.use_count() == 2);
54             assert(pA.use_count() == 2);
55             assert(pA.get() == pB.get());
56             assert(pB.get() == ptrA);
57         }
58         assert(pA.use_count() == 1);
59         assert(B::count == 1);
60         assert(A::count == 1);
61     }
62     assert(B::count == 0);
63     assert(A::count == 0);
64     {
65         const std::shared_ptr<A> pA;
66         A* ptrA = pA.get();
67         {
68             std::shared_ptr<A> pB(new A);
69             pB = pA;
70             assert(B::count == 0);
71             assert(A::count == 0);
72             assert(pB.use_count() == 0);
73             assert(pA.use_count() == 0);
74             assert(pA.get() == pB.get());
75             assert(pB.get() == ptrA);
76         }
77         assert(pA.use_count() == 0);
78         assert(B::count == 0);
79         assert(A::count == 0);
80     }
81     assert(B::count == 0);
82     assert(A::count == 0);
83     {
84         const std::shared_ptr<A> pA(new A);
85         A* ptrA = pA.get();
86         {
87             std::shared_ptr<A> pB;
88             pB = pA;
89             assert(B::count == 1);
90             assert(A::count == 1);
91             assert(pB.use_count() == 2);
92             assert(pA.use_count() == 2);
93             assert(pA.get() == pB.get());
94             assert(pB.get() == ptrA);
95         }
96         assert(pA.use_count() == 1);
97         assert(B::count == 1);
98         assert(A::count == 1);
99     }
100     assert(B::count == 0);
101     assert(A::count == 0);
102     {
103         const std::shared_ptr<A> pA;
104         A* ptrA = pA.get();
105         {
106             std::shared_ptr<A> pB;
107             pB = pA;
108             assert(B::count == 0);
109             assert(A::count == 0);
110             assert(pB.use_count() == 0);
111             assert(pA.use_count() == 0);
112             assert(pA.get() == pB.get());
113             assert(pB.get() == ptrA);
114         }
115         assert(pA.use_count() == 0);
116         assert(B::count == 0);
117         assert(A::count == 0);
118     }
119     assert(B::count == 0);
120     assert(A::count == 0);
121 }
122