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From: "sebor at roguewave dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/31176] reorder class data members to minimize space waste
Date: Wed, 14 Mar 2007 19:04:00 -0000	[thread overview]
Message-ID: <20070314190420.2049.qmail@sourceware.org> (raw)
In-Reply-To: <bug-31176-1186@http.gcc.gnu.org/bugzilla/>



------- Comment #3 from sebor at roguewave dot com  2007-03-14 19:04 -------
(In reply to comment #1)
> Interesting.  Do the attributes apply to derived classes automatically?  

I would say no.

> 
[...]
> Is D also allowed to reorder members a and b? even with an explicit
> __attribute__((reorder))?

I'm afraid I don't know enough to give an informed answer but my gut tells me
that it might be safer to have the programmer explicitly ask for the base class
padding to be used to store members of the derived class (e.g., via some
creative application of the attribute in the definition of the derived class)
rather than having the compiler do it automatically for them.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31176


  parent reply	other threads:[~2007-03-14 19:04 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-03-14 17:37 [Bug c++/31176] New: " sebor at roguewave dot com
2007-03-14 18:15 ` [Bug c++/31176] " fang at csl dot cornell dot edu
2007-03-14 18:16 ` pinskia at gcc dot gnu dot org
2007-03-14 19:04 ` sebor at roguewave dot com [this message]
2007-03-14 19:06 ` sebor at roguewave dot com
2007-03-14 19:09 ` pinskia at gcc dot gnu dot org
2007-03-15 19:54 ` sebor at roguewave dot com
2007-03-15 19:55 ` sebor at roguewave dot com
2007-03-15 23:51 ` sebor at roguewave dot com
2007-04-28  0:37 ` pinskia at gcc dot gnu dot org
     [not found] <bug-31176-4@http.gcc.gnu.org/bugzilla/>
2014-09-03  0:56 ` richard-gccbugzilla at metafoo dot co.uk

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