1c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant//===----------------------------------------------------------------------===// 2c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant// 3c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant// The LLVM Compiler Infrastructure 4c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant// 5b64f8b07c104c6cc986570ac8ee0ed16a9f23976Howard Hinnant// This file is dual licensed under the MIT and the University of Illinois Open 6b64f8b07c104c6cc986570ac8ee0ed16a9f23976Howard Hinnant// Source Licenses. See LICENSE.TXT for details. 7c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant// 8c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant//===----------------------------------------------------------------------===// 9c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant 10c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant// <memory> 11c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant 12c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant// weak_ptr 13c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant 14c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant// template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) 15c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant 16c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant#include <memory> 17c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant#include <cassert> 18c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant 19c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnantstruct A 20c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant{ 21c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant static int count; 22c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant 23c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant A() {++count;} 24c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant A(const A&) {++count;} 25c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant ~A() {--count;} 26c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant}; 27c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant 28c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnantint A::count = 0; 29c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant 30c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnantint main() 31c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant{ 32c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant { 33c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant A* ptr1 = new A; 34c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant A* ptr2 = new A; 35c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant std::shared_ptr<A> p1(ptr1); 36c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant std::weak_ptr<A> w1(p1); 37c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant { 38c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant std::shared_ptr<A> p2(ptr2); 39c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant std::weak_ptr<A> w2(p2); 40c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant swap(w1, w2); 41c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant assert(w1.use_count() == 1); 42c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant assert(w1.lock().get() == ptr2); 43c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant assert(w2.use_count() == 1); 44c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant assert(w2.lock().get() == ptr1); 45c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant assert(A::count == 2); 46c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant } 47c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant } 48c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant assert(A::count == 0); 49c52f43e72dfcea03037729649da84c23b3beb04aHoward Hinnant} 50