#include <iostream> #include <memory> class Woman; class Man{ private: std::weak_ptr<Woman> _wife; //std::shared_ptr<Woman> _wife; public: void setWife(std::shared_ptr<Woman> &woman){ _wife = woman; } void doSomthing(){ if (_wife.lock()){ } } ~Man(){ std::cout << "kill man "; } }; class Woman{ private: //std::weak_ptr<Man> _husband; std::shared_ptr<Man> _husband; public: void setHusband(std::shared_ptr<Man> &man){ _husband = man; } ~Woman(){ std::cout << "kill woman "; } }; int main() { std::shared_ptr<Man> m(new Man()); std::shared_ptr<Woman> w(new Woman()); if (m && w) { m->setWife(w); w->setHusband(m); } return 0; }