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 // shared_ptr 13 14 // template<class Y> shared_ptr(shared_ptr<Y>&& r); 15 16 #include <memory> 17 #include <type_traits> 18 #include <cassert> 19 20 struct B 21 { 22 static int count; 23 BB24 B() {++count;} BB25 B(const B&) {++count;} ~BB26 virtual ~B() {--count;} 27 }; 28 29 int B::count = 0; 30 31 struct A 32 : public B 33 { 34 static int count; 35 AA36 A() {++count;} AA37 A(const A&) {++count;} ~AA38 ~A() {--count;} 39 }; 40 41 int A::count = 0; 42 43 struct C 44 { 45 static int count; 46 CC47 C() {++count;} CC48 C(const C&) {++count;} ~CC49 virtual ~C() {--count;} 50 }; 51 52 int C::count = 0; 53 main()54int main() 55 { 56 static_assert(( std::is_convertible<std::shared_ptr<A>, std::shared_ptr<B> >::value), ""); 57 static_assert((!std::is_convertible<std::shared_ptr<B>, std::shared_ptr<A> >::value), ""); 58 static_assert((!std::is_convertible<std::shared_ptr<A>, std::shared_ptr<C> >::value), ""); 59 { 60 std::shared_ptr<A> pA(new A); 61 assert(pA.use_count() == 1); 62 assert(B::count == 1); 63 assert(A::count == 1); 64 { 65 B* p = pA.get(); 66 std::shared_ptr<B> pB(std::move(pA)); 67 assert(B::count == 1); 68 assert(A::count == 1); 69 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES 70 assert(pB.use_count() == 1); 71 assert(pA.use_count() == 0); 72 #else // _LIBCPP_HAS_NO_RVALUE_REFERENCES 73 assert(pB.use_count() == 2); 74 assert(pA.use_count() == 2); 75 #endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES 76 assert(p == pB.get()); 77 } 78 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES 79 assert(pA.use_count() == 0); 80 assert(B::count == 0); 81 assert(A::count == 0); 82 #else // _LIBCPP_HAS_NO_RVALUE_REFERENCES 83 assert(pA.use_count() == 1); 84 assert(B::count == 1); 85 assert(A::count == 1); 86 #endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES 87 } 88 assert(B::count == 0); 89 assert(A::count == 0); 90 { 91 std::shared_ptr<A> pA; 92 assert(pA.use_count() == 0); 93 assert(B::count == 0); 94 assert(A::count == 0); 95 { 96 std::shared_ptr<B> pB(pA); 97 assert(B::count == 0); 98 assert(A::count == 0); 99 assert(pB.use_count() == 0); 100 assert(pA.use_count() == 0); 101 assert(pA.get() == pB.get()); 102 } 103 assert(pA.use_count() == 0); 104 assert(B::count == 0); 105 assert(A::count == 0); 106 } 107 assert(B::count == 0); 108 assert(A::count == 0); 109 } 110