On 2013-06-28 11:48, Thomas Heller wrote:
trying out the enum34 module.

What I want to create is a subclass of enum.Enum that is also
based on ctypes.c_int so that I can better use enum instances
in ctypes api calls.

When I do this, I get a metaclass conflict:


 >>> class MyEnum(ctypes.c_int, enum.Enum):
...    FOOBAR = 0
...
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
TypeError: Error when calling the metaclass bases
     metaclass conflict: the metaclass of a derived class must be a (non-strict)
subclass of the metaclasses of all its bases
 >>>



When I do this, it does not work either:

 >>> class MyEnum_meta(type(ctypes.c_int), type(enum.Enum)):
...     pass

enum.EnumMeta uses super() in its __new__() implementation but _ctypes.PyCSimpleType doesn't. Thus, only _ctypes.PyCSimpleType.__new__() gets a chance to run. Switching the order of the two might work.

--
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco

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