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{-# LANGUAGE CPP #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE UnicodeSyntax #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Main (main) where
import Prelude
import Data.Default
#if __GLASGOW_HASKELL__ == 704
import qualified Data.Vector.Generic
import qualified Data.Vector.Generic.Mutable
#endif
import Data.Vector.Unboxed.Base (Unbox)
import Data.Vector.Unboxed.Deriving
derivingUnbox "Maybe"
[t| ∀ a. (Default a, Unbox a) ⇒ Maybe a → (Bool, a) |]
[| maybe (False, def) (\ x → (True, x)) |]
[| \ (b, x) → if b then Just x else Nothing |]
main ∷ IO ()
main = return ()
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