I ran across a similar problem when I implemented my observable_value suggestion (http://lists.boost.org/Archives/boost/2007/06/123263.php) and wanted to write a generic operator<T>= for all operators (+=, /=, %= and so on). The problem with operators of built-in types seems a bit related to those of constructors; you can't treat them as ordinary function pointers. It'd be great if this proposed library could solve this "operator problem" too. IMHO, a solution to the operator problem is not near as important but if there is a general and not much more complicated solution to both, it would be great. Best Regards, Johan Torp -- View this message in context: http://www.nabble.com/boost%3A%3Afactory--tf3937069.html#a11541145 Sent from the Boost - Dev mailing list archive at Nabble.com.