#include 
     
      using namespace std;class action{public:    action(){}    ~action(){}    void forward(){cout<<"forward"<
      
       forward();}    void unexecute(){act->backward();}private:    action *act;};class Switch{public:    Switch():cmd(new buttoncommand){}    ~Switch(){}    void open(){cmd->execute();}    void close(){cmd->unexecute();}private:    command *cmd;};int main(){    Switch *sw=new Switch;    sw->open();    sw->close();    delete sw;    system("pause");    return 0;}