Path: utzoo!attcan!uunet!samsung!uakari.primate.wisc.edu!unmvax!pprg.unm.edu!topgun!mustang!nntp-server.caltech.edu!juliet.caltech.edu!gceych
From: gceych@juliet.caltech.edu (Eychaner, Glenn C.)
Newsgroups: comp.lang.c
Subject: Re: Need help with union trick: summary of replies
Message-ID: <1991Jan13.072418.1745@nntp-server.caltech.edu>
Date: 13 Jan 91 06:11:03 GMT
References: <28949@mimsy.umd.edu> <2885@cirrusl.UUCP> <1991Jan12.190021.16071@nntp-server.caltech.edu> <14836@smoke.brl.mil>
Sender: news@nntp-server.caltech.edu
Reply-To: gceych@juliet.caltech.edu
Organization: California Institute of Technology
Lines: 37
News-Software: VAX/VMS VNEWS 1.3-4x
Nntp-Posting-Host: juliet.caltech.edu

In article <14836@smoke.brl.mil>, gwyn@smoke.brl.mil (Doug Gwyn) writes...
>In article <1991Jan12.190021.16071@nntp-server.caltech.edu> gceych@juliet.caltech.edu writes:
>- struct {
>-     variant_union {
>- 	unsigned char ch;
>- 	variant_struct {
>- 	    unsigned one : 1;
>- 	    unsigned two : 1;
>- 	    ...
>- 	    unsigned eig : 1;
>- 	} superfluous;
>-     } superfluous2;
>-     int i, j, k, x, y, z;
>- } mystructure;
> 
>Oh, gross.  If you use this highly nonstandard VMS C extension then
>you'll have to overhaul your code when you port it to a different
>environment.  It is much better to simply not use such unnecessary
>vendor-specific extensions in the first place.

The piece of code of which this is a small part contains so many system calls,
kludges, etc. that portability is not a major concern.  In fact, it was written
for a VAX station bought to eventually replace an 11/44.  At that rate of
replacement, the language will be obsolete before the code is. (The programs on
the 11/44 were written in an early Fortran.  Gross.  Which is just what they'll
think of VaxC by the time the programming needs to be ported.)

Besides, I happen to LIKE this particular construct for nested structures and
unions (as an option).  I hate remembering the names of all the intermediates.
Especially when the variables are all going to have different names anyway.

Direct flames to bit.bucket, please.

Glenn C. Eychaner | "We demand rigidly defined areas of doubt and uncertainty."
40386 N. Shore Ln `-----.                                             -D. Adams
Big Bear City, CA 92314 `-----------------------. !**** G O  N I N E R S ****!
Eychaner%SunCub.Caltech.edu@Xhmeia.Caltech.edu -|- Big Bear Solar Observatory