A hashability problem

[Lantua]

To quote @jrose:

@jrose

...but today the way to spell "choose a particular (or alternate) conformance" in Swift is "use a wrapper type". I do think it should be easier to define and use such types, but Swift isn't unique here; I don't know of any languages with generics that don't use wrapper types for this besides ML.

which should also apply equally as well here.