gistfile1.ec

class Engine
{
   virtual void ::spec(any_object object);
}
class Wheel
{
   virtual void ::nos(any_object object);
}
 
class CarWheel : Wheel
{
   void spec(Car car)
   {
 
   }
}
 
class CarEngine : Engine
{
   void nos(Car car)
   {
 
   }
}
 
class Car
{
   subclass(Engine) engine; engine = class(CarEngine);
   subclass(Wheel)  wheel; wheel = class(CarWheel);
}
 
void SomethingThatDealsWithAnEngine(subclass(Engine) engineClass, any_object i)
{
   engineClass.spec(i);
}
 
void Test()
{
   Car car { };
   SomethingThatDealsWithAnEngine(car.engine, car);
}