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From: Cyrille <comar@eu.adacore.com>
Newsgroups: comp.lang.ada
Subject: Re: Preventing type extensions
Date: Mon, 13 Sep 2010 05:55:39 -0700 (PDT)
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Date: 2010-09-13T05:55:39-07:00
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> Some time ago on c.l.a. we had a long discussion on the goodness or
> badness of re-dispatch, without coming to an agreement. I don't want to
> repeat that discussion, just to point out, again, that Dmitry's opinion
> is not universal.

Far from it indeed. In order to follow the "simple dispatch" rule as
described in OOTiA, one need to (almost) systematically re-dispatch.
It seems to me that the vulnerabilities associated with not following
the simple dispatch rule are significant: it is difficult to guarantee
the integrity of the objects that are manipulated as soon as view
conversions are used or some primitives ops are inherited while others
are overridden.
I understand the arguments in the other direction (against redispatch)
but they do not look so compelling to me, especially in a context
where LSP is understood and verified.