[C++] Class Member Function 의 저장과 호출

참조 : Gof Design Pattern

Command 패턴에 나온 예이다

  
#include <iostream>
using namespace std;

class Command
{
public:
	virtual void Execute() = 0;
};

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

	SimpleCommand(Receiver* r, Action a) : _receiver(r), _action(a) {}
	virtual void Execute();

private:
	Action _action;
	Receiver* _receiver;
};

template<class Receiver>
void SimpleCommand<Receiver>::Execute()
{
	(_receiver->*_action)();
}


class MyClass
{
public:
	MyClass() {}
	MyClass(const MyClass &) {}
	MyClass(const MyClass *) {}
	void MyAction() { cout << "MyClass Action\n"; }
};

int main(void)
{
	MyClass* receiver = new MyClass;
	Command* aCommand = new SimpleCommand<MyClass>(receiver, &MyClass::MyAction);
	aCommand->Execute();
}

형정의
typedef void (Receiver::*Action) ();

전달
Action _action =  &MyClass::MyAction;

호출
(_receiver->*_action)();



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