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From: Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: System.Address to Access to function/procedure conversion
Date: Sun, 28 Jul 2013 10:19:18 -0700
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Date: 2013-07-28T10:19:18-07:00
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On 07/28/2013 08:27 AM, Tarek Ghaleb wrote:
>
> As for why not just pass an Access to the function directly, the
> Address is actually passed to a C function which later passes it back
> to Ada.

If you want any semblance of portability, then you should never pass an Address 
to C. You should only pass a C-convention access type. The value must be stored 
as a pointer on the C side, and there is no guarantee that Ada's Address has any 
relationship to a C pointer. A C-convention access type, on the other hand, is 
guaranteed to make sense as a C pointer.

-- 
Jeff Carter
"Oh Lord, bless this thy hand grenade, that with it thou
mayst blow thine enemies to tiny bits, in thy mercy."
Monty Python and the Holy Grail
24