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 // weak_ptr(const weak_ptr& 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 struct C 44 { 45 static int count; 46 47 C() {++count;} 48 C(const C&) {++count;} 49 virtual ~C() {--count;} 50 }; 51 52 int C::count = 0; 53 54 int main() 55 { 56 { 57 const std::shared_ptr<A> ps(new A); 58 const std::weak_ptr<A> pA(ps); 59 assert(pA.use_count() == 1); 60 assert(B::count == 1); 61 assert(A::count == 1); 62 { 63 std::weak_ptr<A> pB(pA); 64 assert(B::count == 1); 65 assert(A::count == 1); 66 assert(pB.use_count() == 1); 67 assert(pA.use_count() == 1); 68 } 69 assert(pA.use_count() == 1); 70 assert(B::count == 1); 71 assert(A::count == 1); 72 } 73 assert(B::count == 0); 74 assert(A::count == 0); 75 { 76 std::weak_ptr<A> pA; 77 assert(pA.use_count() == 0); 78 assert(B::count == 0); 79 assert(A::count == 0); 80 { 81 std::weak_ptr<A> pB(pA); 82 assert(B::count == 0); 83 assert(A::count == 0); 84 assert(pB.use_count() == 0); 85 assert(pA.use_count() == 0); 86 } 87 assert(pA.use_count() == 0); 88 assert(B::count == 0); 89 assert(A::count == 0); 90 } 91 assert(B::count == 0); 92 assert(A::count == 0); 93 } 94
