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From: maxtal@physics.su.OZ.AU (John Max Skaller)
Subject: Re: Multiple inheritance and delete
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References: <Ct8xyr.Ivq@borland.com> <1994Jul21.021936.314@corona.com>
Date: Mon, 25 Jul 1994 15:26:05 GMT
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In article <1994Jul21.021936.314@corona.com> pkron@corona.com writes:
>From: pete@genghis.interbase.borland.com (Pete Becker)
>>  In article <1994Jul20.044817.698@corona.com>,
>>  Peter Kron <pkron@corona.com> wrote:
>>>Clearly this is not desirable behavior, but is a side effect of trying
>>>to minimize storage for vtables and pointers to them. The concept of
>>>polymorphism should imply that *objects* determine how they respond to
>>>member functions, not callers.
>>  
>>  Clearly, the design decision for this pair of
>>  classes was that they are not polymorphic. That
>>  is not a language flaw, but a deliberate decision on the
>>  part of the designer of these classes. If you want the
>>  call to memberFunction() to be virtual, design your
>>  classes appropriately.
>
>Polymorphism is central to using C++ as an OOPL rather than just as
>a better of C. If polymorphism is not desired, it would be much more
>appropriate to use a different member name rather than overriding
>memberFunction. As I suggested, a keyword could be defined to provide
>non-polymorphic overrides, but that would be the exception rather than
>the rule.

	Yes it could but the default is the other way around.
Big deal. Its just a default, it has a historical basis.
C++ has a history, you know. Read Stroustrup's Design & Evolution.

>>  Please don't impose your design criteria on the rest of
>>  the world.
>
>Hmmm. It would seem the language is imposing the criteria, not me.
>I'm suggesting changes that I believe would reduce a lot of
>difficulty, based on some recent threads.

	It would also break REAMS of C++ code, for no good
reason other than to change a default to your liking.
Even if your liking is shared by many, that is not enough
to zap almost all C++ code in existence.

	As it happens, I think the default is correct.
(See discussion here some time back on "private virtual" methods)

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        JOHN (MAX) SKALLER,         INTERNET:maxtal@suphys.physics.su.oz.au
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