Add tests from testsuite/tests/h98

[ghc-base.git] / GHC / STRef.lhs

diff --git a/GHC/STRef.lhs b/GHC/STRef.lhs
index 5eecb85..9306b24 100644 (file)
--- a/GHC/STRef.lhs
+++ b/GHC/STRef.lhs
@@ -1,5 +1,7 @@
 \begin{code}
-{-# OPTIONS -fno-implicit-prelude #-}
+{-# LANGUAGE NoImplicitPrelude, MagicHash, UnboxedTuples #-}
+{-# OPTIONS_HADDOCK hide #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  GHC.STRef
@@ -14,6 +16,7 @@
 --
 -----------------------------------------------------------------------------
 
+-- #hide
 module GHC.STRef where
 
 import GHC.ST
@@ -39,10 +42,6 @@ writeSTRef (STRef var#) val = ST $ \s1# ->
     case writeMutVar# var# val s1#      of { s2# ->
     (# s2#, () #) }
 
--- |Mutate the contents of an 'STRef'
-modifySTRef :: STRef s a -> (a -> a) -> ST s ()
-modifySTRef ref f = readSTRef ref >>= writeSTRef ref . f
-
 -- Just pointer equality on mutable references:
 instance Eq (STRef s a) where
     STRef v1# == STRef v2# = sameMutVar# v1# v2#