Use explicit language extensions & remove extension fields from base.cabal

[ghc-base.git] / System / Mem / Weak.hs

diff --git a/System/Mem/Weak.hs b/System/Mem/Weak.hs
index e6a8a37..21411e5 100644 (file)
--- a/System/Mem/Weak.hs
+++ b/System/Mem/Weak.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  System.Mem.Weak
@@ -67,10 +69,9 @@ module System.Mem.Weak (
        -- $precise
    ) where
 
-import Prelude
-
 #ifdef __HUGS__
 import Hugs.Weak
+import Prelude
 #endif
 
 #ifdef __GLASGOW_HASKELL__
@@ -104,7 +105,7 @@ mkWeakPtr key finalizer = mkWeak key key finalizer
 -}
 addFinalizer :: key -> IO () -> IO ()
 addFinalizer key finalizer = do
-   mkWeakPtr key (Just finalizer)      -- throw it away
+   _ <- mkWeakPtr key (Just finalizer) -- throw it away
    return ()
 
 -- | A specialised version of 'mkWeak' where the value is actually a pair