Metaclass with name overloading.

[Alex Martelli]

Jacek Generowicz <jacek.generowicz at cern.ch> wrote:

> imbosol at aerojockey.com (Carl Banks) writes:
> 
> >     def alltuple(name,bases,clsdict):
> >         return tuple(clsdict.values())
> >             __metaclass__ = alltuple
> 
> WBMSWA12FB !
> 
> It never occurred to me that a metaclass didn't have to be a _class_.

You should have seen Guido's face when he first saw me give a
presentation on "use and abuse of custom metaclasses" -- apparently,
judging from his horrified expression, it hadn't occurred to him,
either, and he didn't like it half a bit... since then I've been quite
careful against actually using this idea in production code.

Actually I believed I showed something more like:

class whatever:
    def __metaclass__(clsname, clsbases, clsdict):
        return <I don't remember what>
    ...etc etc...

i.e., an "anonymous metaclass", so to speak.  But that's a minor aspect.
After all, something like:

class yetanother:
    class __metaclass__(type):
        ...etc etc...

is just as so-to-speak "anonymous" yet IS nowadays quite an accepted
idiom...!


Alex