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 T, class U> shared_ptr<T> const_pointer_cast(const shared_ptr<U>& 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<const A> pA(new A); 47 std::shared_ptr<A> pB = std::const_pointer_cast<A>(pA); 48 assert(pB.get() == pA.get()); 49 assert(!pB.owner_before(pA) && !pA.owner_before(pB)); 50 } 51 { 52 const std::shared_ptr<const A> pA; 53 std::shared_ptr<A> pB = std::const_pointer_cast<A>(pA); 54 assert(pB.get() == pA.get()); 55 assert(!pB.owner_before(pA) && !pA.owner_before(pB)); 56 } 57 } 58
