I'm not intimate with Python's C/C++ implementation, but is it possible that your modified code may not be implementation portable? For instance, if some calculation of the size of the object is required, inherited classes may layout data differently than contained classes would, especially if classes do not contain a "nice" (i.e., word-boundary) number of bytes.
Or is it possible that there are other Python routines that access the mBase field, perhaps for some form of introspection? What you might do is convert one of the existing typedefs to use your form, then build an run Python regression tests, preferably on Win, Mac, and *nix. Or at least run your own alternative PyStructDerivedClass through a series of tests that specifically target and exercise the class hierarchy. (I'm sorry if I'm proposing an onerous build/test burden, but if you want your C++ code to generally adopted, while straying from accepted practices, then you should probably prepare to put in some extra effort to validate your alternative approach.) I agree, your approach looks much cleaner. Unfortunately, in the face of having to support many platforms and compilers, Python implementation and extension may constrain developers to a clearly portable subset of language features. -- Paul -- http://mail.python.org/mailman/listinfo/python-list
