#if ( defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ > 502 ) || \
    ( defined(__NHC__) && __NHC__ > 114 ) || defined(__HUGS__)
import System.IO.Unsafe (unsafePerformIO)
#elif defined(__GLASGOW_HASKELL__)
import IOExts (unsafePerformIO)
#elif defined(__NHC__)
import IOExtras (unsafePerformIO)
#elif defined(__HBC__)
import UnsafePerformIO
#endif