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From: linton@sgi.com (Mark Linton)
Newsgroups: comp.lang.c++
Subject: Re: Nonvirtual base classes in MI
Message-ID: <1991Jan31.164927.3234@odin.corp.sgi.com>
Date: 31 Jan 91 16:49:27 GMT
References: <1159@zinn.MV.COM>
Sender: news@odin.corp.sgi.com (Net News)
Reply-To: linton@sgi.com (Mark Linton)
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In article <1159@zinn.MV.COM>, mjv@objects.mv.com (Michael J. Vilot) writes:
|> Scott Meyers asked for an example of using multiple inheritance without using
|> virtual base classes.  I used exactly this approach in the design of the C++
|> Booch Components library, to use mixin classes to achieve a couple of purposes.

 I think you missed the point of Scott's question.  You describe a situation
in which you did not need virtual base classes.  What Scott asked is if any one needs
non-virtual base classes.  Presumably, your code would have functioned correctly
if you had made all your derivations virtual (in fact, you really should make all your
reference counting derivations virtual because you don't want a descendant
to have multiple ref counts).

I would like to echo the original question, as I also have not encountered
a situation where I need non-virtual base classes.