Identity function with special treatment to Bool values, by @Player-205

Cursed.hs

{-# LANGUAGE MagicHash, UnboxedTuples #-}
import GHC.Prim
import Unsafe.Coerce
import Prelude hiding (id)

main :: IO ()
main = do
  print (id True)
  print (id False)
  print (id 15)
  print (id 13.47)
  print (id "one, two, three")
  print (id (True, False))
  
id :: a -> a
id !a = case (# eqT, eqF #) of
  (# 0#, 1# #) -> t
  (# 1#, 0# #) -> f
  _ -> a
  where
    eqT = reallyUnsafePtrEquality# a t
    eqF = reallyUnsafePtrEquality# a f
    !t = unsafeCoerce True 
    !f = unsafeCoerce False 

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