build on ghc-7.4

yihuang · Jan 31, 2012 · 41cf215 · 41cf215
1 parent 94c71e4
commit 41cf215
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/Database/MySQL/Base.hs b/Database/MySQL/Base.hs
@@ -554,7 +554,7 @@ withMaybeString :: Maybe String -> (CString -> IO a) -> IO a
 withMaybeString Nothing act = act nullPtr
 withMaybeString (Just xs) act = withCString xs act
 
-check :: Num a => String -> Connection -> a -> IO ()
+check :: (Eq a, Num a) => String -> Connection -> a -> IO ()
 check func conn r = unless (r == 0) $ connectionError func conn
 {-# INLINE check #-}