Disable templetized operators by default

To avoid nasty bugs due to silently overriding of
common operator we enable the templates on a type
by type base using partial template specialization.

No functional change, zero overhead at runtime.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/square.h

@@ -64,6 +64,11 @@ enum SquareDelta {
   DELTA_NN = 020, DELTA_NNE = 021
 };
 
+ENABLE_OPERATORS_ON(Square);
+ENABLE_OPERATORS_ON(File);
+ENABLE_OPERATORS_ON(Rank);
+ENABLE_OPERATORS_ON(SquareDelta);
+
 
 ////
 //// Constants