{-# LANGUAGE CPP, BangPatterns, MagicHash, UnboxedTuples #-}
module FastMutInt(
FastMutInt, newFastMutInt,
readFastMutInt, writeFastMutInt
) where
#define SIZEOF_HSINT 4
import GHC.Exts
# if __GLASGOW_HASKELL__>=612
import GHC.IO (IO(IO))
#else
import GHC.IOBase (IO(IO))
#endif
data FastMutInt = FastMutInt (MutableByteArray# RealWorld)
newFastMutInt :: IO FastMutInt
newFastMutInt = IO $ \s ->
case newByteArray# size s of { (# s, arr #) ->
(# s, FastMutInt arr #) }
where !(I# size) = SIZEOF_HSINT
readFastMutInt :: FastMutInt -> IO Int
readFastMutInt (FastMutInt arr) = IO $ \s ->
case readIntArray# arr 0# s of { (# s, i #) ->
(# s, I# i #) }
writeFastMutInt :: FastMutInt -> Int -> IO ()
writeFastMutInt (FastMutInt arr) (I# i) = IO $ \s ->
case writeIntArray# arr 0# i s of { s ->
(# s, () #) }