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From: "Steve" <nospam_steved94@comcast.net>
Newsgroups: comp.lang.ada
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Subject: Re: Conditional compilation in Ada?
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Date: 2004-11-20T02:56:35+00:00
List-Id: <comp.lang.ada>

Several years ago on this newsgroup there was a thread discussing tagged
types with abstract methods.  In the discussion I was suprised to hear that
it was permissible to declare an instance of a type having abstract methods.
It kind of stuck in my mind.

I tried searching google groups for a reference to the original thread and
couldn't find it.  It may have had something to do with dispatching on
access types (?).

Prior to reading about it here, I had assumed that it was not possible to
create an instance of an object with abstract methods.  If that proves to be
the case, I think its a good thing.

Steve
(The Duck)


"Simon Wright" <simon@pushface.org> wrote in message
news:x7vvfc1bjy9.fsf@smaug.pushface.org...
> "Steve" <nospam_steved94@comcast.net> writes:
>
> > "Alex R. Mosteo" <devnull@mailinator.com> wrote in message
> > news:419CE3F5.6010906@mailinator.com...
> > [snip]
> > > >
> > > > And operations that are mistakenly not overridden become run-time
> > errors.
> > >
> > > Not if they're declared abstract. Then you have the same situation as
> > > missing cases for a variant record. Plus you don't have an escape like
> > > using "when others".
> > >
> >
> > Actually in Ada I don't believe there is anything keeping you from
> > declaring an instance of an object that has abstract methods (unlike
> > C++).  That was my recollection, I created a small test program to
> > verify and that was my result.
>
> Sounds like a buggy compiler! suggest you have another go ..
>
> -- 
> Simon Wright                               100% Ada, no bugs.