From:	Erik Max Francis <max AT alcyone DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Help: My structure members aren't getting the right offsets!
Date:	Mon, 24 Feb 1997 00:19:22 -0800
Organization:	Alcyone Systems
Lines:	22
Message-ID:	<33114F0A.2E800353@alcyone.com>
References:	<3310E089 DOT 78F9 AT osha DOT igs DOT net>
NNTP-Posting-Host:	newton.alcyone.com
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Delong wrote:

> I even made code that added up the 'sizeof' each element and got 512
> bytes, please let me know if you know whats goind wrong here (since all
> data after VBEVersion_Major is getting screwed, but before that it
> works).

The problem is that you're assuming that all of the structure members are
packed perfectly, and you can't make this assumption with ANSI C (or draft
standard C++).  The compiler may add padding as it sees fit, to optimize
(or even allow!) more efficient references to the members.

What you're looking for is the packed attribute; check the info pages.
Note that this is, by its very nature, nonstandard.

-- 
       Erik Max Francis, &tSftDotIotE / email:  max AT alcyone DOT com
                     Alcyone Systems /    web:  http://www.alcyone.com/max/
San Jose, California, United States /    icbm:  37 20 07 N  121 53 38 W
                                   \
              "I am become death, / destroyer of worlds."
                                 / J. Robert Oppenheimer (quoting legend)

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