1 //===----------------------------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
14 // template<class Y> shared_ptr(const shared_ptr<Y>& r);
17 #include <type_traits>
25 B(const B&) {++count;}
26 virtual ~B() {--count;}
37 A(const A&) {++count;}
48 C(const C&) {++count;}
49 virtual ~C() {--count;}
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), "");
60 const std::shared_ptr<A> pA(new A);
61 assert(pA.use_count() == 1);
62 assert(B::count == 1);
63 assert(A::count == 1);
65 std::shared_ptr<B> pB(pA);
66 assert(B::count == 1);
67 assert(A::count == 1);
68 assert(pB.use_count() == 2);
69 assert(pA.use_count() == 2);
70 assert(pA.get() == pB.get());
72 assert(pA.use_count() == 1);
73 assert(B::count == 1);
74 assert(A::count == 1);
76 assert(B::count == 0);
77 assert(A::count == 0);
79 std::shared_ptr<A> pA;
80 assert(pA.use_count() == 0);
81 assert(B::count == 0);
82 assert(A::count == 0);
84 std::shared_ptr<B> pB(pA);
85 assert(B::count == 0);
86 assert(A::count == 0);
87 assert(pB.use_count() == 0);
88 assert(pA.use_count() == 0);
89 assert(pA.get() == pB.get());
91 assert(pA.use_count() == 0);
92 assert(B::count == 0);
93 assert(A::count == 0);
95 assert(B::count == 0);
96 assert(A::count == 0);