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-- Test restricted functionality: Data.Typeable
:unset +s
:set -XSafe
:set -XDeriveDataTypeable
:set -XStandaloneDeriving
:m + Data.OldTypeable
data H = H {h :: String} deriving (Typeable, Show)
data G = G [Int] deriving (Show)
instance Typeable G where { typeOf _ = typeOf (undefined :: H) }
let x = H "Hello"
let y = G [0]
x
y
let (Just y_as_H) = (cast y) :: Maybe H
y_as_H
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