As mentioned by Steven there are other ways to this without Interfaces. Templates are one very nice way and you may also find:
AutoImplements BlackHole WhiteHole http://digitalmars.com/d/2.0/phobos/std_typecons.html#AutoImplement Useful. I thought there was also going to be something that would take a given class and derive it from a base class to assume the type. But I guess that isn't in Phobos.
