Generic for unlifted types

[kozross]

Currently, you cannot derive Generic for an unlifted type, specifically one defined using the new UnliftedDatatypes extension. Would it be possible to lift this restriction?

[kosmikus]

I don't know. In general, Generic is currently limited to types of kind Type / *. Generalising this a bit is in principle possible, and I've primarily never had the time to merge these generalisations.

However, for unlifted types, a different sort of generalisation is needed. I guess conceptually we would need unlifted versions of NS and NP to represent these. I'm currently not sure whether all this is worth it.