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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Seeking for papers about tagged types vs access to subprograms
Date: Thu, 2 May 2013 08:56:30 +0200
Organization: cbb software GmbH
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Date: 2013-05-02T08:56:30+02:00
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On Wed, 1 May 2013 20:09:46 -0500, Randy Brukardt wrote:

> "Yannick Duch魥 (Hibou57)" <yannick_duchene@yahoo.fr> wrote in message 
> news:op.wv8jh1c1ule2fv@cardamome...
> ...
>>As an additional aside but related question, I'm also interested in the 
>>question in the particular context of storage-pools, which use tagged 
>>types instead of simple sub-program designated by some attributes or 
>>operator overloading (I imagine simple sub-programs could have been an 
>>option for the `new` operator, just like for the other operators).
> 
> Nitpick: "new" is not an operator, it is an *operation*, things whose 
> behavior cannot be modified directly. Like membership, it would be hard to 
> make "new" an operator because one of the arguments can be a type (rather 
> than an object or value), and it's hard to see how that could be mapped to 
> an Ada function. (Adding type parameters seems over the top.)

   type Root_Access_Type is interface ...;
   function "new" return Root_Access_Type is abstract;

If access types were "untagged" class, "new" would be a plain primitive
operation.

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