In my interpreter, I have several primitive wrapper objects: IntObject, FloatObject, etc. Currently I'm planning to create functions for every combination: def add_int_float(i, f): return FloatObject(i.int_value() + f.float_value()) then I'd need some sort of dispatch code that would say if isinstance(arg1, IntObject) and isinstance(arg2, FloatObject): return add_int_float(arg1, arg2) It seems like pypy should have something to do this already. I saw some information on this but that seemed specific to the Python interpreter. What's the recommended procedure on this? Is there a way to tell pypy "this object wraps a single value, so keep it unwrapped if you can", or does pypy figure that out automagically? Thanks, Timothy -- “One of the main causes of the fall of the Roman Empire was that–lacking zero–they had no way to indicate successful termination of their C programs.” (Robert Firth)