DoubleDispatcher: 가상함수를 이용한 방법

#include <windows.h>
#include <tchar.h>

#include <typeinfo>
#include <iostream>

using namespace std;

class SpaceShip;
class SpaceStation;
class Asteriod;

class GameObject
{
public:
 virtual void Collide(GameObject& otherObject) = 0;

public:
 virtual void Collide(SpaceShip& otherObject) = 0;
 virtual void Collide(SpaceStation& otherObject) = 0;
 virtual void Collide(Asteriod& otherObject) = 0;

 virtual ~GameObject();
};

class SpaceShip: public GameObject
{
public:
 virtual void Collide(GameObject& otherObject);
public:
 virtual void Collide(SpaceShip& otherObject);
 virtual void Collide(SpaceStation& otherObject);
 virtual void Collide(Asteriod& otherObject);
};

class SpaceStation: public GameObject
{
public:
 virtual void Collide(GameObject& otherObject);
public:
 virtual void Collide(SpaceShip& otherObject);
 virtual void Collide(SpaceStation& otherObject);
 virtual void Collide(Asteriod& otherObject);
};

class Asteriod: public GameObject
{
public:
 virtual void Collide(GameObject& otherObject);
public:
 virtual void Collide(SpaceShip& otherObject);
 virtual void Collide(SpaceStation& otherObject);
 virtual void Collide(Asteriod& otherObject);
};

GameObject::~GameObject()
{
}

void SpaceShip::Collide(GameObject& otherObject)
{
 otherObject.Collide(*this);
}

void SpaceShip::Collide(SpaceShip& otherObject)
{
 cout << "The space ship is colliding with a space ship";
 cout << endl;
}

void SpaceShip::Collide(SpaceStation& otherObject)
{
 cout << "The space ship is colliding with a space station";
 cout << endl;
}

void SpaceShip::Collide(Asteriod& otherObject)
{
 cout << "The space ship is colliding with a asteriod";
 cout << endl;
}

void SpaceStation::Collide(GameObject& otherObject)
{
 otherObject.Collide(*this);
}

void SpaceStation::Collide(SpaceShip& otherObject)
{
 cout << "The space station is colliding with a space ship";
 cout << endl;
}

void SpaceStation::Collide(SpaceStation& otherObject)
{
 cout << "The space station is colliding with a space station";
 cout << endl;
}

void SpaceStation::Collide(Asteriod& otherObject)
{
 cout << "The space station is colliding with a asteriod";
 cout << endl;
}

void Asteriod::Collide(GameObject& otherObject)
{
 otherObject.Collide(*this);
}

void Asteriod::Collide(SpaceShip& otherObject)
{
 cout << "The space ship is colliding with a space ship";
 cout << endl;
}

void Asteriod::Collide(SpaceStation& otherObject)
{
 cout << "The space ship is colliding with a space station";
 cout << endl;
}

void Asteriod::Collide(Asteriod& otherObject)
{
 cout << "The space ship is colliding with a asteriod";
 cout << endl;
}

int _tmain (int argc, _TCHAR* argv[])
{
 GameObject  *p1;
 GameObject  *p2;

 SpaceShip    ship;
 SpaceStation station;
 Asteriod     asteriod;

 p1 = &ship;
 p2 = &ship;     p1->Collide(*p2);
 p2 = &station;  p1->Collide(*p2);
 p2 = &asteriod; p1->Collide(*p2);

 return 0;
}
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The space ship is colliding with a space ship
The space station is colliding with a space ship
The space ship is colliding with a space ship