(Modern C++) override, final

class Player
{
public:
    void Attack()
    {
        cout << "Player" << endl;
    }
};

class Knight : public Player
{
public:
    void Attack()   // override
    {
        cout << "Knight" << endl;
    }

    // cf) overloading : 함수 이름의 재사용
}

int main()
{
    Knight* knight = new Knight();
    knight->Attack();   // Knight

    Player* player = new Knight();
    player->Attack();   // Player : 원하던 정보가 아님!
}

class Player
{
public:
    virtual void Attack()
    {
        cout << "Player" << endl;
    }
};

// ...

int main()
{
    Player* player = new Knight();
    player->Attack();   // Knight : Okay!
}

class Knight : public Player
{
public:
    void Attack() override
    {
        cout << "Knight" << endl;
    }

    void Attack() const override    // Error - 부모에 있는지도 확인이 가능

    // ...