Workaround for deriving Repr in types with non Repr fields

Stream: new members

[Luis Enrique Muñoz Martín]

Hi, I have a structure that contains a HashMap field, which does not implement Repr. What's the common workaround to have my struct with Repr:

structure MyType where
  nonRepr : HashMap Nat Int  -- This does not implement Repr
deriving Repr -- <- I want to do this

[Henrik Böving]

You can have a custom instance : Repr MyType if you want.

[Kyle Miller]

Or define instance [Repr X] [Repr Y] : Repr (HashMap X Y) first