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From: ado@elsie.UUCP (Arthur David Olson)
Newsgroups: net.lang.c
Subject: Re: CTRL(X) in ANSI standard
Message-ID: <5137@elsie.UUCP>
Date: Tue, 28-May-85 10:35:55 EDT
Article-I.D.: elsie.5137
Posted: Tue May 28 10:35:55 1985
Date-Received: Thu, 30-May-85 02:08:01 EDT
References: <10747@brl-tgr.ARPA> <507@ucsfcgl.UUCP>
Organization: NIH-LEC, Bethesda, MD
Lines: 23
Summary: the draft standard makes "a"[0] a constant

In regard to

	#define CTRL(XX) ( (#XX)[0] & '\037')

in article <507@ucsfcgl.UUCP>, arnold@ucsfcgl.UUCP (Ken Arnold%CGL) writes:

> . . .Unless the compiler is incredibly smart, this won't work in 'case'
> statements, which is rather important. . .
> Actually, when you think about it, since strings are writeable, "a"[0]
> is NOT a constant, since someone else might modify the string. . .

Although if I understand aright the draft standard treats unadorned doubly-
quoted strings as if they were cast to "const", which means that constructs
like "a"[0] would be constants under the draft standard.

As for me, I still favor the
	#define Ctrl(X) ((X) & '\037')
approach.  Change your source once and be done with it.
--
Ken is a Kenner Corporation trademark.
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