1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // <memory>
10 
11 // shared_ptr
12 
13 // template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p);
14 
15 #include <memory>
16 #include <cassert>
17 
18 #include "test_macros.h"
19 
20 struct B
21 {
22     static int count;
23 
BB24     B() {++count;}
BB25     B(const B&) {++count;}
~BB26     ~B() {--count;}
27 };
28 
29 int B::count = 0;
30 
31 struct A
32 {
33     static int count;
34 
AA35     A() {++count;}
AA36     A(const A&) {++count;}
~AA37     ~A() {--count;}
38 };
39 
40 int A::count = 0;
41 
main(int,char **)42 int main(int, char**)
43 {
44     {
45         std::shared_ptr<A> pA(new A);
46         assert(pA.use_count() == 1);
47 
48         {
49             B b;
50             std::shared_ptr<B> pB(pA, &b);
51             assert(A::count == 1);
52             assert(B::count == 1);
53             assert(pA.use_count() == 2);
54             assert(pB.use_count() == 2);
55             assert(pB.get() == &b);
56         }
57         assert(pA.use_count() == 1);
58         assert(A::count == 1);
59         assert(B::count == 0);
60     }
61     assert(A::count == 0);
62     assert(B::count == 0);
63 
64     {
65         std::shared_ptr<A const> pA(new A);
66         assert(pA.use_count() == 1);
67 
68         {
69             B const b;
70             std::shared_ptr<B const> pB(pA, &b);
71             assert(A::count == 1);
72             assert(B::count == 1);
73             assert(pA.use_count() == 2);
74             assert(pB.use_count() == 2);
75             assert(pB.get() == &b);
76         }
77         assert(pA.use_count() == 1);
78         assert(A::count == 1);
79         assert(B::count == 0);
80     }
81     assert(A::count == 0);
82     assert(B::count == 0);
83 
84     int *pi = new int;
85     {
86       std::shared_ptr<int> p1(nullptr);
87       std::shared_ptr<int> p2(p1, pi);
88       assert(p2.get() == pi);
89     }
90     delete pi;
91     {
92       std::shared_ptr<int> p1(new int);
93       std::shared_ptr<int> p2(p1, nullptr);
94       assert(p2.get() == nullptr);
95     }
96 
97 #if TEST_STD_VER > 17 && defined(_LIBCPP_VERSION)
98     // This won't pass when LWG-2996 is implemented.
99     {
100       std::shared_ptr<A> pA(new A);
101       assert(pA.use_count() == 1);
102 
103       {
104         B b;
105         std::shared_ptr<B> pB(std::move(pA), &b);
106         assert(A::count == 1);
107         assert(B::count == 1);
108         assert(pA.use_count() == 2);
109         assert(pB.use_count() == 2);
110         assert(pB.get() == &b);
111       }
112       assert(pA.use_count() == 1);
113       assert(A::count == 1);
114       assert(B::count == 0);
115     }
116     assert(A::count == 0);
117     assert(B::count == 0);
118 #endif
119 
120     return 0;
121 }
122