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From: Brian Drummond <brian@shapes.demon.co.uk>
Newsgroups: comp.lang.ada
Subject: Re: Legit Warnings or not
Date: Thu, 21 Jul 2011 21:30:50 +0000 (UTC)
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On Thu, 21 Jul 2011 10:40:38 -0700, Jeffrey Carter wrote:

> On 07/21/2011 02:50 AM, Brian Drummond wrote:
>>
>> Interesting. Do you mean they allocate a new object? Then how do they
>> handle the following declarations
>>     X : aliased Warned_Person;
>>     Y : access Warned_Person := X'access;
>> when X.Name is resized?
> 
> I should have said such compilers change the space for the
> variable-sized components, not the space for the entire object, so X
> remains in a constant position. I'm not a compiler writer so I'm not
> entirely sure what's involved in implementing such an approach.
> 

Seems that this implies that either (a: unlikely) the variable-sized 
component MUST remain in place in the record (which makes resizing it all 
but impossible) or (b: would work) the record must contain an ACCESS to 
it (in which case the implementation silently does something other than 
the declaration says).

Either way has surprises : if the actual result is (c: Dmitry option 3) 
the prohibition of aliasing for e.g. records with default discriminants, 
I would not lose any sleep and probably be relieved...

- Brian