[Boost-users] [enable_if] using enable_if to extend std::numeric_limits?

Suppose I have a set of templates that have a common interface (each is a model of the same concept, to use that lingo). I'd like to extend std::numeric_limits to support this concept. I'm trying to find a way to use enable_if to do this, but I don't see how. Is this possible? Is there some other trick to doing this? Example with code (not real code): template< class U, class V > class model1; tempalte< class U, class V > class model2; template< class U > is_decimal_type { static const bool value = false; }; template< class U, class V > is_decimal_type < model1 > { static const bool value = true; }; template< class U, class V > is_decimal_type < model2 > { static const bool value = true; }; Would like to do this: template< class T > class numeric_limits< T > { // extensions go here }; But only if is_decimal_type<T>::value is true (so that the partial specialization only applies to my concept). Thanks, - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837