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From: Robert A Duff <bobduff@shell01.TheWorld.com>
Newsgroups: comp.lang.ada
Subject: Re: Adding offset to 'Address
Date: Fri, 12 Sep 2008 17:40:53 -0400
Organization: The World Public Access UNIX, Brookline, MA
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Date: 2008-09-12T17:40:53-04:00
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Adam Beneschan <adam@irvine.com> writes:

>   (Ethernet_Header'Size + System.Storage_Unit - 1) /
> System.Storage_Unit
>
> which rounds the size in bits up to the next multiple of
> System.Storage_Unit.  [System.Storage_Unit will equal 8 on most
> systems.]

It seems to me that this sort of thing won't work unless
System.Storage_Unit is 8 bits.  So you don't want rounding up.
It seems better to say:

    pragma Assert (System.Storage_Unit = 8);
    ... Raw_Bytes.all'Address + Ethernet_Header'Size/8 ...

If you really need to do this sort of thing, that is.

- Bob