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{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE UndecidableInstances #-}
{-# LANGUAGE UndecidableSuperClasses #-}
module Bug where
import Data.Kind
type family
AllF (c :: k -> Constraint) (xs :: [k]) :: Constraint where
AllF _c '[] = ()
AllF c (x ': xs) = (c x, All c xs)
class (AllF c xs, SListI xs) => All (c :: k -> Constraint) (xs :: [k]) where
instance All c '[] where
instance (c x, All c xs) => All c (x ': xs) where
class Top x
instance Top x
type SListI = All Top
class All SListI (Code a) => Generic (a :: Type) where
type Code a :: [[Type]]
data T = MkT Int
instance Generic T where
type Code T = '[ '[Int] ]
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