Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!uicsrd.csrd.uiuc.edu!davies
From: davies@uicsrd.csrd.uiuc.edu
Newsgroups: comp.lang.c
Subject: Re: sizeof a struc field
Message-ID: <44200027@uicsrd.csrd.uiuc.edu>
Date: 12 Oct 89 21:16:00 GMT
References: <7710@microsoft.UUCP>
Lines: 17
Nf-ID: #R:microsoft.UUCP:7710:uicsrd.csrd.uiuc.edu:44200027:000:691
Nf-From: uicsrd.csrd.uiuc.edu!davies    Oct 12 16:16:00 1989


gwyn@smoke.BRL.MIL writes re: using sizeof((type *)0->field:
**
**No, there IS no type information, because the construct is
**officially meaningless.  You THINK you know what type was MEANT,
**but the compiler is not obliged to mimic your thought processes.
**
**This is not an issue about sizeof, but rather about ->.

If it is "officially meaningless" to use (type *)0->field,
would it be "officially meaningful" to instead substitute
(type *)1->field?
After all, the pointer is no longer NULL, so it must be ok, right?

This whole discussion seems a bit abstract - can anybody cite references
from the standard or examples of compiler behaviour when confronted
with something like this?