[project @ 2003-01-23 11:46:57 by ross]

add Ord instance, as per FFI spec

diff --git a/Foreign/ForeignPtr.hs b/Foreign/ForeignPtr.hs
index a1e8550..01969de 100644 (file)
--- a/Foreign/ForeignPtr.hs
+++ b/Foreign/ForeignPtr.hs
@@ -18,7 +18,7 @@
 module Foreign.ForeignPtr
         ( 
        -- * Finalised data pointers
-         ForeignPtr             -- abstract, instance of: Eq
+         ForeignPtr             -- abstract, instance of: Eq, Ord, Show
         , newForeignPtr          -- :: Ptr a -> IO () -> IO (ForeignPtr a)
         , addForeignPtrFinalizer -- :: ForeignPtr a -> IO () -> IO ()
        , withForeignPtr         -- :: ForeignPtr a -> (Ptr a -> IO b) -> IO b
@@ -95,6 +95,9 @@ data ForeignPtr a
 instance Eq (ForeignPtr a) where 
     p == q  =  foreignPtrToPtr p == foreignPtrToPtr q
 
+instance Ord (ForeignPtr a) where 
+    compare p q  =  compare (foreignPtrToPtr p) (foreignPtrToPtr q)
+
 instance Show (ForeignPtr a) where
     showsPrec p f = showsPrec p (foreignPtrToPtr f)