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From: Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: Question about package Interfaces.
Date: Tue, 14 Sep 2010 09:36:43 -0700
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Date: 2010-09-14T09:36:43-07:00
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On 09/13/2010 11:33 PM, J-P. Rosen wrote:
>
> Imagine that you declared:
> X : Unsigned_8;
> and you discover that the declaration advances the data counter by 4
> bytes. You can interpret that as X occupying 32 bits, or as X occupying
> only 8 bits with 3 unused padding bytes ahead of it.
>
> There is positively no way to tell the difference.

You could examine the machine code to see if it does 4-byte or 1-byte load and 
stores.

This might be important if X were, say, a memory-mapped control register for a 
H/W device. But then, I'd expect to see

for X'Size use 8;
for X'Address use ...;

-- 
Jeff Carter
"To Err is human, to really screw up, you need C++!"
St�phane Richard
63

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