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From: davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr)
Newsgroups: comp.lang.c
Subject: Re: sizeof a struc field
Message-ID: <1423@crdos1.crd.ge.COM>
Date: 24 Oct 89 17:11:50 GMT
References: <7710@microsoft.UUCP> <11316@smoke.BRL.MIL> <7685@cdis-1.uucp> <2488@munnari.oz.au>
Reply-To: davidsen@crdos1.UUCP (bill davidsen)
Organization: GE Corp R&D Center
Lines: 15

In article <2488@munnari.oz.au>, ok@cs.mu.oz.au (Richard O'Keefe) writes:

|  I'm sure I'll be corrected if I'm wrong, but isn't the actual restriction
|  that the argument of "sizeof" must be an L-value in ANSI C?  If I'm right
|  about that, then the problem is not that sizeof ((struct foo*)NULL)->field
|  may "blow up", but that ((struct foo*)NULL)->field is not an L-value.

  The standard says that you may take the sizeof an array, so the
expression most definitely does not have to be an lvalue. You can also
take sizeof something const.
-- 
bill davidsen	(davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen)
"The world is filled with fools. They blindly follow their so-called
'reason' in the face of the church and common sense. Any fool can see
that the world is flat!" - anon