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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: Interfacing between Ada and C: records and structs
Date: Tue, 31 Jul 2012 20:27:07 +0100
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Date: 2012-07-31T20:27:07+01:00
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awdorrin <awdorrin@gmail.com> writes:

> I am wondering if the Dummy element in the Mutex record is not being
> treated as a null, but as a null pointer, adding 8 bytes to the record
> size.

If you say

   type Dummy is null record;

then no space is reserved for the tag.

But if that is OK, what is it _for_? Normally something like this is
needed to pad out parts of a C struct that you don't need to bother
with, but that's clearly not the case here.