Dan Albert | 287553d | 2017-02-16 10:47:51 -0800 | [diff] [blame] | 1 | //===----------------------------------------------------------------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is dual licensed under the MIT and the University of Illinois Open |
| 6 | // Source Licenses. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | |
| 10 | // <memory> |
| 11 | |
| 12 | // weak_ptr |
| 13 | |
| 14 | // template<class Y> weak_ptr& operator=(const weak_ptr<Y>& r); |
| 15 | |
| 16 | #include <memory> |
| 17 | #include <type_traits> |
| 18 | #include <cassert> |
| 19 | |
| 20 | struct B |
| 21 | { |
| 22 | static int count; |
| 23 | |
| 24 | B() {++count;} |
| 25 | B(const B&) {++count;} |
| 26 | virtual ~B() {--count;} |
| 27 | }; |
| 28 | |
| 29 | int B::count = 0; |
| 30 | |
| 31 | struct A |
| 32 | : public B |
| 33 | { |
| 34 | static int count; |
| 35 | |
| 36 | A() {++count;} |
| 37 | A(const A&) {++count;} |
| 38 | ~A() {--count;} |
| 39 | }; |
| 40 | |
| 41 | int A::count = 0; |
| 42 | |
| 43 | int main() |
| 44 | { |
| 45 | { |
| 46 | const std::shared_ptr<A> ps(new A); |
| 47 | const std::weak_ptr<A> pA(ps); |
| 48 | { |
| 49 | std::weak_ptr<B> pB; |
| 50 | pB = pA; |
| 51 | assert(B::count == 1); |
| 52 | assert(A::count == 1); |
| 53 | assert(pB.use_count() == 1); |
| 54 | assert(pA.use_count() == 1); |
| 55 | } |
| 56 | assert(pA.use_count() == 1); |
| 57 | assert(B::count == 1); |
| 58 | assert(A::count == 1); |
| 59 | } |
| 60 | assert(B::count == 0); |
| 61 | assert(A::count == 0); |
| 62 | |
| 63 | { |
| 64 | const std::shared_ptr<A> ps(new A); |
| 65 | std::weak_ptr<A> pA(ps); |
| 66 | { |
| 67 | std::weak_ptr<B> pB; |
| 68 | pB = std::move(pA); |
| 69 | assert(B::count == 1); |
| 70 | assert(A::count == 1); |
| 71 | assert(pB.use_count() == 1); |
| 72 | } |
| 73 | assert(B::count == 1); |
| 74 | assert(A::count == 1); |
| 75 | } |
| 76 | assert(B::count == 0); |
| 77 | assert(A::count == 0); |
| 78 | } |