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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Community Input for the Maintenance and Revision of the Ada
 Programming Language
Date: Tue, 5 Sep 2017 17:29:15 -0500
Organization: JSA Research & Innovation
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Xref: news.eternal-september.org comp.lang.ada:47939
Date: 2017-09-05T17:29:15-05:00
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"Alejandro R. Mosteo" <alejandro@mosteo.com> wrote in message 
news:ooglev$c4u$1@dont-email.me...
> On 03/09/17 03:35, Randy Brukardt wrote:
...
>>       subtype Zero_Array is Integer_Array (0 .. Item'Length - 1);
>>       X : Zero_Array := Zero_Array (Item);
>
> Wouldn't that possibly involve a copy? If so, would using "constant" 
> guarantee a free renaming?

Yes, it involves a copy. (I thought of that after sending the message, 
should have mentioned it.)

90% of the time (and 100% of the time when I would use this, exclusively for 
Strings), the copy isn't consequential.

The remaining 10% of the time, use the original bounds (it isn't that hard).

> And is there a difference to using rename?:

Renames ignores the bounds of the renames; I explained why in the reply to 
Dmitry.

                             Randy.