command 模式 (类模板实现)

#include <iostream>
using namespace std;

class Receiver
{
      public:
              Receiver(){}
              void print() { cout << "hello, world!" << endl;}
};

template < class receiver>
class SimpleCommand
{
      public:
              typedef void (receiver::*Action)();

              SimpleCommand(receiver* r, Action p):_receiver(r),_action(p){}

              void Execute() { (_receiver->*_action)();}

      private:
              receiver* _receiver;
              Action _action;
};


int main()
{
     Receiver * r;
     SimpleCommand<Receiver> command(r, &Receiver::print);
     command.Execute();
     system("pause");
     return 0;
}