This needs a different approach

[Saaa]

>
> I'm more into solving this using classes and inheritance. If the compiler 
> can do the function table for you, why bother?

I can understand your position ;)
But I didn't use any classes.

If the compiler would optimize the switch to a function table anyways I 
would just keep it like it is now although learning to use classes in D 
sounds intriguing as well.