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From: "G.B." <bauhaus@notmyhomepage.invalid>
Newsgroups: comp.lang.ada
Subject: Re: renaming as classwide type
Date: Thu, 21 Sep 2023 23:03:02 +0200
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On 21.09.23 21:29, Simon Belmont wrote:
> is it really illegal to rename an object as it's classwide parent?  gnat claims so.  Similar results using a type extension as a generic formal "in out" object of classwide type.
> 
>    declare
>      type P is interface;
>      type C is new P with null record;
>    
>      o : C;
>      r : P'Class renames o;  --error
>      begin
>        null;
>      end;
> 
> expected type "P'Class" defined at line
> found type "C" defined at line

O does not denote an object of a class-wide type,
I think. However, P'Class (o) does, so that renaming
that would make r be of its declared type P'Class.