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Mail Archives: djgpp/1996/10/07/01:12:39

From: "John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: packed data structures?
Date: Sun, 06 Oct 1996 23:56:58 -0700
Organization: Three pounds of chaos and a pinch of salt
Lines: 31
Message-ID: <3258A9B9.21EF@cs.com>
References: <52nl1a$kqv AT news2 DOT cnct DOT com> <32574F0D DOT 215B AT lux DOT latrobe DOT edu DOT au>
Reply-To: fighteer AT cs DOT com
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To: Natasha and Don <fstcns AT lux DOT latrobe DOT edu DOT au>
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

Natasha and Don wrote:
> 
> John Panettiere wrote:
> >
> > Hello, all.
> >
> > ... realized that djgpp wasn't packing the data structures - so I browsed
> > the info files and found "__attribute__((packed))", which seemed to be
> > the answer I was looking for.
> 
> Hmm I suspect that your problem is that you are using C++,
> __attribute__ ((packed)) only seems to work for C. I have exactly
> the same problem myself and am thinking of using bitfields (barf)!
> 
> Does any one else have any ideas?

*sigh*.  If only more people would read the FAQ.  There is a bug in the
gcc compiler that makes it not pack structures correctly in C++.  You
have to surround the structure you want packed with #pragma pack(1) ...
#pragma pack().  The FAQ (v2/faq201b.zip) talks about this exact problem
in section 22.10.

Eli, DJ?  Is there a fixed version of gcc in v2.01?  A lot of people
would be curious to know.  :)

-- 
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| John M. Aldrich, aka Fighteer I  |        fighteer AT cs DOT com         |
| Plan:  To find ANYONE willing to |   http://www.cs.com/fighteer   |
| play Descent 2 on DWANGO!        | Tagline: <this space for rent> |
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