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From: gceych@juliet.caltech.edu (Eychaner, Glenn C.)
Newsgroups: comp.lang.c
Subject: Re: Need help with union trick: summary of replies
Message-ID: <1991Jan12.190021.16071@nntp-server.caltech.edu>
Date: 12 Jan 91 18:51:15 GMT
References: <1991Jan4.192645.7094@lavaca.uh.edu> <4977:Jan422:17:0191@kramden.acf.nyu.edu> <28949@mimsy.umd.edu> <2885@cirrusl.UUCP>
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dhesi%cirrusl@oliveb.ATC.olivetti.com (Rahul Dhesi) writes...
>I sort of like calling the union substructure by tiny names like x, y,
>z etc.  Then references become struct_name.x.field_name, and the ".x."
>is almost not noticeable.  The idea is to use a small meaningless name
>(sort of using i, j, k as loop counters) so the meaningfullness (to
>coin a noun) lies entirely in the name of the structure and the name of
>the field.
>--
Me (in VaxC, I don't know if others support it) use variant_structures and
variant_unions. Example:

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;

So you can reference the first bit of ch as mystructure.one, the second as
mystructure.two, ch as mystructure.ch, i as mystructure.i, etc.  All the
variables must have different names, BTW.  I use this for storing bit flags
to a file as a char or int (to avoid huge scanf statements and files full
of 1's & 0's).

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