{-# LANGUAGE DeriveFunctor, DatatypeContexts #-}
module ShouldFail where
-- Derive Functor on a type that uses 'a' in the wrong places
newtype InFunctionArgument a = InFunctionArgument (a -> Int)
deriving (Functor)
newtype OnSecondArg a = OnSecondArg (Either a a)
deriving (Functor)
-- Derive Functor on a type with no arguments
newtype NoArguments = NoArguments Int
deriving (Functor)
-- Derive Functor on a type with extra stupid-constraints on 'a'
data Eq a => StupidConstraint a = StupidType a
deriving (Functor)
-- A missing Functor instance
data NoFunctor a = NoFunctor
data UseNoFunctor a = UseNoFunctor (NoFunctor a)
deriving (Functor)