🚀 go-pugleaf

In article <1992Dec11.165754.9910@Cadence.COM> cox@cadence.com (Henry Cox) writes:
>(I posted this last night - it did not appear on our systems, so I am
>posting it a second time.  I apologize for any duplication you see.)
>
>I ran into an interesting situation with respect to multiple
>inheritance and [initialising] virtual base classes.  

>Comments?  Suggestions?  
>
	Markku Sakkinen has written a paper on this issue, due to
appear in the C++ Report I believe. it is generally felt
that initialisation by the 'join' class should be used.
	Another idea I put forward was to use the name dominance
rule, but this would require the ctor initialisers to be part
of the interface.

	The real question is 'why am I initialising virtual bases',
and 'how do I explain that there are *different* initialisers'.
It should be that if a base is initialised at all, it is initialised
in only one way. This is enforced for single inheritance by
only allowing initialisation of direct bases, and for virtual bases
by insisting that the most derived class initialises them,
even if not direct bases, so any other initialisers are unfortunately
ignored.

	This phenomenon is extremely annoying when using mixins,
when all the abstract base classes are virtual, and the whole lot
have to be initialised in the most derived class.

	A general rule of thumb would appear to be that candidates
for shared base status should never require non-default initialisation,
since this is the only reasonable way to have unique initialisation.

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