I'd say that that's an example of structural or duck typing (as opposed to nominal typing). In my experience it is nigh impossible to design-pattern your way o

I'd say that that's an example of structural or duck typing (as opposed to nominal typing). In my experience it is nigh impossible to design-pattern your way out of a language simply being unable to express what you need it to express without incurring a severe performance penalty (anathema for game development) or resorting to code generation (which is itself prone to ending up as a Gordian knot).