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From: Victor Porton <porton@narod.ru>
Newsgroups: comp.lang.ada
Subject: Re: Deallocating an object twice
Date: Sun, 27 Jul 2014 18:34:03 +0300
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Date: 2014-07-27T18:34:03+03:00
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Stephen Leake wrote:

> Victor Porton <porton@narod.ru> writes:
> 
>> If I understand correctly, it is an undefined behavior (or is it called
>> unbounded error?) if a pool access is deallocated twice with
>> Unchecked_Deallocation.
> 
> You misunderstand.
> 
> ARM 2012 13.11.3
> 
> Procedure Free has the following effect:
> 
> 7
>      1.  After executing Free(X), the value of X is null.
> 
> 8
>      2.  Free(X), when X is already equal to null, has no effect.

No, it is that you misunderstand me:

Second free may be executed not as Free(X) but as Free(Y) where Y was a copy 
of X (and so Free(X) sets only X to null, it does not set Y to null; and 
Free(Y) would be erroneous).

-- 
Victor Porton - http://portonvictor.org