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From: "Ehud Lamm" <mslamm@mscc.huji.ac.il>
Newsgroups: comp.lang.ada
Subject: Re: Container reqs
Date: Thu, 18 Oct 2001 22:52:48 +0200
Organization: The Hebrew University of Jerusalem
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Date: 2001-10-18T22:52:48+02:00
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Simon Wright <simon@pushface.org> wrote in message
news:x7v4royhk79.fsf@smaug.pushface.org...
> "Ehud Lamm" <mslamm@mscc.huji.ac.il> writes:
>
> > The way I see it, if it is impossible - or just very hard - to
> > provide default instantiaions, it is likely that the design is bad
> > anyway.
>
> I don't see how you can provide containers that can contain anything
> at all in Ada.
>
> You could have containers that were capable of handling anything in
> Containable_Object'Class, I guess (but you'd need access types, 'Class
> is unconstrained).

I guess we are talking different things here.

I have no problem with a Queue package paraemtrized by an Element type
(specified as private). Even novice Ada programmer must know how to
instantiate such packages if he uses Text_IO.
What I dodn't like is the need for several, possibly nested, instantiations
simply to get a simple queue or hash table.

Ehud