Base methods in unit

src/Unit.cpp

@@ -57,3 +57,9 @@ void Unit::checkBounds() {
     if (y < MIN_Y) y = MIN_Y;
     if (y > MAX_Y) y = MAX_Y;
 }
+
+// Default implementation
+bool Unit::isAlive() const { return true; }
+bool Unit::isToBeJunked() const { return false; }
+void Unit::doCrash() {}
+void Unit::draw(QGraphicsScene *) const {}