testsuite/tests/ado/T13242.hs


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-- Panic.hs
{-# LANGUAGE ApplicativeDo #-}
{-# LANGUAGE ExistentialQuantification #-}
module T13242 where

import Data.STRef
import Control.Monad.ST

data A = forall a. A a

st :: ST s ()
st = do
      A _ <- pure $ A True
      ref <- newSTRef 1
      readSTRef ref
      pure ()