I was wondering if it's possible to have automatic deriving for some classes for the Void type. This would be classes that require a parameter of the type in its functions. This should obviously be trivial as the definition can be undefined since there's no way to supply a value of the type.

I guess the obvious one would be Show.

data Nada deriving Show

{*

instance Show Nada where

  show _ = undefined

*}

Thoughts?