> On Aug 30, 2019, at 13:26, Oliver Charles <ollie@ocharles.org.uk> wrote:

>
> I haven't really thought it out, but I wonder if
>
> newtype GenericallyUsing a c
>
> Also works, paving the way for other generic classes.

I don’t think this really adds anything over just having two newtypes, personally. `generics-sop` could, of course, always export its own newtype for this purpose, also named `Generically` or otherwise, and I think that would be simpler without any real disadvantages. I don’t think there are very many situations where you could be usefully polymorphic in the second type parameter of `GenericallyUsing`.