Using -XEmptyDataDecls I can declare an (almost) empty data type. ``` data Void ``` However, I can't use an empty case to discriminate values of the empty type. This does not work: ``` get :: Void -> a ``` Only the type signature, but no body. \[This would be useful also in other circumstances.\] ``` get :: Void -> a get v = case v of { } ``` An empty case in the body.