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// weak_ptr
12
13// template<class Y> weak_ptr& operator=(const shared_ptr<Y>& r);
14
15#include <memory>
16#include <type_traits>
17#include <cassert>
18
19#include "test_macros.h"
20
21struct B
22{
23 static int count;
24
25 B() {++count;}
26 B(const B&) {++count;}
27 virtual ~B() {--count;}
28};
29
30int B::count = 0;
31
32struct A
33 : public B
34{
35 static int count;
36
37 A() {++count;}
38 A(const A& other) : B(other) {++count;}
39 ~A() {--count;}
40};
41
42int A::count = 0;
43
44int main(int, char**)
45{
46 {
47 const std::shared_ptr<A> pA(new A);
48 assert(pA.use_count() == 1);
49 {
50 std::weak_ptr<B> pB;
51 pB = pA;
52 assert(B::count == 1);
53 assert(A::count == 1);
54 assert(pB.use_count() == 1);
55 assert(pA.use_count() == 1);
56 }
57 assert(pA.use_count() == 1);
58 assert(B::count == 1);
59 assert(A::count == 1);
60 }
61 assert(B::count == 0);
62 assert(A::count == 0);
63
64#if TEST_STD_VER > 14
65 {
66 const std::shared_ptr<A[]> p1(new A[8]);
67 assert(p1.use_count() == 1);
68 {
69 std::weak_ptr<const A[]> p2;
70 p2 = p1;
71 assert(A::count == 8);
72 assert(p2.use_count() == 1);
73 assert(p1.use_count() == 1);
74 }
75 assert(p1.use_count() == 1);
76 assert(A::count == 8);
77 }
78 assert(A::count == 0);
79#endif
80
81 return 0;
82}
83

source code of libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/shared_ptr_Y.pass.cpp