X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=System%2FTimeout.hs;h=df33625c8d4cca3f8b51052c4c87492481d4cd5f;hb=be2750a0a11b919fb03cc070074e430f88bdfa90;hp=f27a936ed29edb9a984c7088bd40c8ccde5c3a3b;hpb=2ebff97f8efea061ec2c51d8dd8fa19dd880243d;p=ghc-base.git

diff --git a/System/Timeout.hs b/System/Timeout.hs
index f27a936..df33625 100644
--- a/System/Timeout.hs
+++ b/System/Timeout.hs
@@ -1,3 +1,8 @@
+{-# LANGUAGE CPP #-}
+#ifdef __GLASGOW_HASKELL__
+{-# LANGUAGE DeriveDataTypeable, StandaloneDeriving #-}
+#endif
+
 -------------------------------------------------------------------------------
 -- |
 -- Module      :  System.Timeout
@@ -27,13 +32,12 @@ import Control.Concurrent  (forkIO, threadDelay, myThreadId, killThread)
 import Control.Exception   (Exception, handleJust, throwTo, bracket)
 import Data.Typeable
 import Data.Unique         (Unique, newUnique)
-import GHC.Num
 
 -- An internal type that is thrown as a dynamic exception to
 -- interrupt the running IO computation when the timeout has
 -- expired.
 
-data Timeout = Timeout Unique deriving Eq
+newtype Timeout = Timeout Unique deriving Eq
 INSTANCE_TYPEABLE0(Timeout,timeoutTc,"Timeout")
 
 instance Show Timeout where