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From: Martin Krischik <krischik@users.sourceforge.net>
Newsgroups: comp.lang.ada
Subject: Re: Is T an ancestor of T?
Date: Fri, 15 Oct 2004 18:55:22 +0200
Organization: AdaCL
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Date: 2004-10-15T18:55:22+02:00
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Georg Bauhaus wrote:

> Martin Krischik <krischik@users.sourceforge.net> wrote:
>  
> :> 'class as return type of constructor functions creates a number of
> :> not-so-nice conversion necessities that I'd like to avoid.
> : 
> : I thought as an example. Not to actually use this constructor pattern.
> 
> Interestingly, GNAT complains if T is derived from some other
> type Base. For example,
> 
>       function Make return T'Class is
>       begin
>          return T'(T with N => 42);
>       end Make;
> 
> 
>      7.          return T'(T with N => 42);
>                            |
>         >>> expect ancestor type of "T"
> 
> (Same for specific T.)

Well T is not an ancestor of T. T is T itself. You might want try the
example with a tagged type which actually has a parent to see the
difference.

With Regards

Martin
-- 
mailto://krischik@users.sourceforge.net
http://www.ada.krischik.com