pre_declaretion.h

这是个很不错的飞行游戏源码

#ifndef GAME_CLASSES_H
#define GAME_CLASSES_H

// 类前向声明
class GameWorld;
class Sprite;
class Bullet;
class FighterPlane;
class Player;
class Display;
class BulletSystem;
class Enermy;
class EnermySystem;
class CollisionSystem;

#endif