int StudentWorld::numOfEnemyProjectiles() { int num = 0; std::list<Actor*>::iterator position; position = m_actors.begin(); while (position != m_actors.end()) { Projectile* a = dynamic_cast<Projectile*>(*position); if (a != NULL) { if (a->enemyOrPlayerProjectile() == ALIEN_BULLET) num++; } position++; } return num; }