From a cursory look through the library doc, it appears that it's possible to create a UDT such that numeric_cast will work with it. For example, class int24 { ... }; // for 24-bit ints; must also specialize // std::numeric_limits, create a range // checking policy, etc. int i; ... int24 myInt = numeric_cast<int24>(i); // throws if i's value won't // fit in an int24 short s = numeric_cast<short>(myInt); // throws if myInt's value won't // fit in a short Can somebody who knows this library please tell me if my understanding is correct -- that numeric_cast can be made to work with integral UDTs? Thanks, Scott