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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Self pointer in limited record
Newsgroups: comp.lang.ada
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Date: Fri, 31 Aug 2007 21:33:05 +0200
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Date: 2007-08-31T21:32:46+02:00
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On Fri, 31 Aug 2007 16:47:29 -0000, amado.alves@gmail.com wrote:

> Then you have seen illegal Ada code repeatedly. I wish this were
> possible myself. Or more simply:
> 
> type T is -- limited or not
>    Self : access T := T'Unchecked_Access;
>    ...
> end;

T cannot be non-limited, because otherwise passing it by copy would make
rubbish out of Self. In any case it would make little sense if not access
T'Class.

--------------
There is an interesting illegal case of objects bound to a specific storage
pool:

   type T is tagged limited private;

private
   type T_Ptr is access T'Class;
   for T_Ptr'Storage_Pool use ...;

   type T is tagged limited record
      Self : T_Ptr := T'Unchecked_Access; -- Illegal
   end record;

The language requires T_Ptr to be a general access type no matter what.

--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de