case writeIntArray# arr 0# i s of { s ->
(# s, () #) }
#else /* ! __GLASGOW_HASKELL__ */
+--maybe someday we could use
+--http://haskell.org/haskellwiki/Library/ArrayRef
+--which has an implementation of IOURefs
+--that is unboxed in GHC and just strict in all other compilers...
newtype FastMutInt = FastMutInt (IORef Int)
-- If any default value was chosen, it surely would be 0,