swap.pass.cpp revision f5256e16dfc425c1d466f6308d4026d529ce9e0b 
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// shared_ptr
13
14// template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b);
15
16#include <memory>
17#include <cassert>
18
19struct A
20{
21    static int count;
22
23    A() {++count;}
24    A(const A&) {++count;}
25    ~A() {--count;}
26};
27
28int A::count = 0;
29
30int main()
31{
32    {
33        A* ptr1 = new A;
34        A* ptr2 = new A;
35        std::shared_ptr<A> p1(ptr1);
36        {
37            std::shared_ptr<A> p2(ptr2);
38            swap(p1, p2);
39            assert(p1.use_count() == 1);
40            assert(p1.get() == ptr2);
41            assert(p2.use_count() == 1);
42            assert(p2.get() == ptr1);
43            assert(A::count == 2);
44        }
45        assert(p1.use_count() == 1);
46        assert(p1.get() == ptr2);
47        assert(A::count == 1);
48    }
49    assert(A::count == 0);
50    {
51        A* ptr1 = new A;
52        A* ptr2 = 0;
53        std::shared_ptr<A> p1(ptr1);
54        {
55            std::shared_ptr<A> p2;
56            swap(p1, p2);
57            assert(p1.use_count() == 0);
58            assert(p1.get() == ptr2);
59            assert(p2.use_count() == 1);
60            assert(p2.get() == ptr1);
61            assert(A::count == 1);
62        }
63        assert(p1.use_count() == 0);
64        assert(p1.get() == ptr2);
65        assert(A::count == 0);
66    }
67    assert(A::count == 0);
68    {
69        A* ptr1 = 0;
70        A* ptr2 = new A;
71        std::shared_ptr<A> p1;
72        {
73            std::shared_ptr<A> p2(ptr2);
74            swap(p1, p2);
75            assert(p1.use_count() == 1);
76            assert(p1.get() == ptr2);
77            assert(p2.use_count() == 0);
78            assert(p2.get() == ptr1);
79            assert(A::count == 1);
80        }
81        assert(p1.use_count() == 1);
82        assert(p1.get() == ptr2);
83        assert(A::count == 1);
84    }
85    assert(A::count == 0);
86    {
87        A* ptr1 = 0;
88        A* ptr2 = 0;
89        std::shared_ptr<A> p1;
90        {
91            std::shared_ptr<A> p2;
92            swap(p1, p2);
93            assert(p1.use_count() == 0);
94            assert(p1.get() == ptr2);
95            assert(p2.use_count() == 0);
96            assert(p2.get() == ptr1);
97            assert(A::count == 0);
98        }
99        assert(p1.use_count() == 0);
100        assert(p1.get() == ptr2);
101        assert(A::count == 0);
102    }
103    assert(A::count == 0);
104}
105