| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // <memory> |
| |
| // weak_ptr |
| |
| // template<class Y> weak_ptr(const shared_ptr<Y>& r); |
| |
| #include <memory> |
| #include <type_traits> |
| #include <cassert> |
| |
| #include "test_macros.h" |
| |
| struct B |
| { |
| static int count; |
| |
| B() {++count;} |
| B(const B&) {++count;} |
| virtual ~B() {--count;} |
| }; |
| |
| int B::count = 0; |
| |
| struct A |
| : public B |
| { |
| static int count; |
| |
| A() {++count;} |
| A(const A&) {++count;} |
| ~A() {--count;} |
| }; |
| |
| int A::count = 0; |
| |
| struct C |
| { |
| static int count; |
| |
| C() {++count;} |
| C(const C&) {++count;} |
| virtual ~C() {--count;} |
| }; |
| |
| int C::count = 0; |
| |
| int main(int, char**) |
| { |
| static_assert(( std::is_convertible<std::shared_ptr<A>, std::weak_ptr<B> >::value), ""); |
| static_assert((!std::is_convertible<std::weak_ptr<B>, std::shared_ptr<A> >::value), ""); |
| static_assert((!std::is_convertible<std::shared_ptr<A>, std::weak_ptr<C> >::value), ""); |
| { |
| const std::shared_ptr<A> pA(new A); |
| assert(pA.use_count() == 1); |
| assert(B::count == 1); |
| assert(A::count == 1); |
| { |
| std::weak_ptr<B> pB(pA); |
| assert(B::count == 1); |
| assert(A::count == 1); |
| assert(pB.use_count() == 1); |
| assert(pA.use_count() == 1); |
| } |
| assert(pA.use_count() == 1); |
| assert(B::count == 1); |
| assert(A::count == 1); |
| } |
| assert(B::count == 0); |
| assert(A::count == 0); |
| { |
| std::shared_ptr<A> pA; |
| assert(pA.use_count() == 0); |
| assert(B::count == 0); |
| assert(A::count == 0); |
| { |
| std::weak_ptr<B> pB(pA); |
| assert(B::count == 0); |
| assert(A::count == 0); |
| assert(pB.use_count() == 0); |
| assert(pA.use_count() == 0); |
| } |
| assert(pA.use_count() == 0); |
| assert(B::count == 0); |
| assert(A::count == 0); |
| } |
| assert(B::count == 0); |
| assert(A::count == 0); |
| |
| return 0; |
| } |