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// shared_ptr<T> lock() const;
14
15#include <memory>
16#include <cassert>
17
18#include "test_macros.h"
19
20struct A
21{
22 static int count;
23
24 A() {++count;}
25 A(const A&) {++count;}
26 ~A() {--count;}
27};
28
29int A::count = 0;
30
31int main(int, char**)
32{
33 {
34 std::weak_ptr<A> wp;
35 std::shared_ptr<A> sp = wp.lock();
36 assert(sp.use_count() == 0);
37 assert(sp.get() == 0);
38 assert(A::count == 0);
39 }
40 {
41 std::shared_ptr<A> sp0(new A);
42 std::weak_ptr<A> wp(sp0);
43 std::shared_ptr<A> sp = wp.lock();
44 assert(sp.use_count() == 2);
45 assert(sp.get() == sp0.get());
46 assert(A::count == 1);
47 }
48 assert(A::count == 0);
49 {
50 std::shared_ptr<A> sp0(new A);
51 std::weak_ptr<A> wp(sp0);
52 sp0.reset();
53 std::shared_ptr<A> sp = wp.lock();
54 assert(sp.use_count() == 0);
55 assert(sp.get() == 0);
56 assert(A::count == 0);
57 }
58 assert(A::count == 0);
59
60 return 0;
61}
62

source code of libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/lock.pass.cpp