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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Ada Interfaces and the Liskov Substitution Principle
Date: Wed, 23 May 2007 16:58:05 -0500
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Date: 2007-05-23T16:58:05-05:00
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"Maciej Sobczak" <see.my.homepage@gmail.com> wrote in message
news:1179953657.839272.160320@a26g2000pre.googlegroups.com...
> On 23 Maj, 21:47, Stefan Lucks <l...@th.informatik.uni-mannheim.de>
> wrote:
>
> > to me, it seems as if Ada 2005 is bluntly violating the Liskov
> > Substitution Prinicple. E.g., define
>
> [...]
>
> Interesting.
>
> My humble opinion: assignment of class-wide types should be prohibited
> in the first place. I mean - at compile time.
> It's just asking for troubles.

That doesn't make much sense. Yes, it is a bit weird that assignment is
potentially a dispatching operation, but otherwise there is no semantic
problem with it. (The OP having an illegal example, thus proving nothing.)
It might be a bit hard to use usefully, but that's no reason for banning it.

                     Randy.