restore Complex's derived Data instance

diff --git a/Data/Complex.hs b/Data/Complex.hs
index 6ebbfcb..bbc8a07 100644 (file)
--- a/Data/Complex.hs
+++ b/Data/Complex.hs
@@ -65,7 +65,11 @@ infix  6  :+
 data (RealFloat a) => Complex a
   = !a :+ !a    -- ^ forms a complex number from its real and imaginary
                 -- rectangular components.
+# if __GLASGOW_HASKELL__
+        deriving (Eq, Show, Read, Data)
+# else
         deriving (Eq, Show, Read)
+# endif
 
 -- -----------------------------------------------------------------------------
 -- Functions over Complex