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-- Exercise 7.1-ii
-- What happens to this instance if you remove the `Show t =>` constraint from
-- `HasShow`.
-- Removing `Show t =>` below makes GHC angry:
--
-- • No instance for ‘Show t’ arising from a use of ‘show’
-- Possible fix:
-- add (Show t) to the context of the data constructor ‘HasShow’
data HasShow where
HasShow :: Show t => t -> HasShow
instance Show HasShow where
show (HasShow t) = "HasShow " <> show t
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