Kevin Teague <ke...@bud.ca> added the comment: The problem with generic functions supporting ABCs is it's a bug with the way ABCs work and not a problem with the generic function implementation. The register() method of an ABC only fakes out isinstance checks, it doesn't actually make the abstract base class a base class of the class. It doesn't make any sense for a class to say it is an instance of an ABC, but not have that ABC in it's MRO. It's not a base class if it's not in the MRO!
The documentation for lack of ABC support should read something like: + Note that generic functions do not work with classes which have + been declared as an abstract base class using the + abc.ABCMeta.register() method because this method doesn't make + that abstract base class a base class of the class - it only fakes + out instance checks. Perhaps a bug should be opened for the abc.ABCMeta.register() method. However, I'd say that just because virtual abstract base classes are wonky doesn't mean that a solid generic function implementation shouldn't be added to standard library. ---------- nosy: +kteague _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue5135> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
