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 // template<class U> bool owner_before(const weak_ptr<U>& b); 15 16 #include <memory> 17 #include <cassert> 18 19 int main() 20 { 21 const std::shared_ptr<int> p1(new int); 22 const std::shared_ptr<int> p2 = p1; 23 const std::shared_ptr<int> p3(new int); 24 const std::weak_ptr<int> w1(p1); 25 const std::weak_ptr<int> w2(p2); 26 const std::weak_ptr<int> w3(p3); 27 assert(!w1.owner_before(w2)); 28 assert(!w2.owner_before(w1)); 29 assert(w1.owner_before(w3) || w3.owner_before(w1)); 30 assert(w3.owner_before(w1) == w3.owner_before(w2)); 31 } 32