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{-# LANGUAGE MagicHash, UnboxedTuples, MultiParamTypeClasses, TypeFamilies,
FunctionalDependencies, KindSignatures, PolyKinds, DataKinds,
UndecidableInstances #-}
module T14185 where
import GHC.Types
import GHC.Prim
class Unbox (t :: *) (r :: TYPE k) | t -> r, r -> t where
unbox :: t -> r
box :: r -> t
instance Unbox Int Int# where
unbox (I# i) = i
box i = I# i
instance Unbox Char Char# where
unbox (C# c) = c
box c = C# c
instance (Unbox a a', Unbox b b') => Unbox (a,b) (# a', b' #) where
unbox (a,b) = (# unbox a, unbox b #)
box (# a, b #) = (box a, box b)
testInt :: Int
testInt = box (unbox 1)
testTup :: (Int, Char)
testTup = box (unbox (1, 'a'))
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