Inheriting from a Type Parameter

[FPGro]

Hi, welcome to the community! See here for a short discussion and the semi-official answer to that request:

Parametrically customized subtypes

I think this is the same feature discussed recently by the Symbolics and Julia compiler teams. I would be interested to see what the experts have to say on this topic. For each of many external abstract types T , I want to make a new abstract subtype of T whose dispatch users control. For example, a const LazyInteger = Lazy{Integer} that’s a subtype of Integer but has custom lazy method implementations. I can implement this for certain types manually, but I don’t think it’s currently possible…