Multiple inheritance with a common base class

[Markus Bertheau]

Hi,

I don't quite get the paragraph in the docs about this. Here it is:

"A well-known problem with multiple inheritance is a class derived from
two classes that happen to have a common base class. While it is easy
enough to figure out what happens in this case (the instance will have a
single copy of ``instance variables'' or data attributes used by the
common base class), it is not clear that these semantics are in any way
useful."

If it's so easy to figure out, what is a problem then? And what should
the comment about usefulness suggest?

Thanks

-- 
Markus Bertheau <twanger at bluetwanger.de>