Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!spool.mu.edu!snorkelwacker.mit.edu!stanford.edu!agate!dog.ee.lbl.gov!elf.ee.lbl.gov!torek
From: torek@elf.ee.lbl.gov (Chris Torek)
Newsgroups: comp.lang.c
Subject: Re: using "=" in a conditional (was Funny Mistake)
Message-ID: <11195@dog.ee.lbl.gov>
Date: 20 Mar 91 20:27:37 GMT
References: <1991Mar20.031419.3677@isis.cs.du.edu>
Reply-To: torek@elf.ee.lbl.gov (Chris Torek)
Organization: Lawrence Berkeley Laboratory, Berkeley
Lines: 18
X-Local-Date: Wed, 20 Mar 91 12:27:37 PST

In article <1991Mar20.031419.3677@isis.cs.du.edu>
cla@isis.UUCP (Chuck Anderson) writes:
>You can do a nice string copy with this construct as well:
>   while (*dest++ = *source++);

Of course, you can also write it as:

	while ((*dest++ = *source++) != 0)	/* or != '\0' */
		/* void */;

which will leave no doubt in the reader's mind that you meant `test
the result of copying one element', and not `test one pair of elements'.
Commenting the empty statement (here, with `void', though `do nothing'
or `continue' or `skip' or ... are all fine) will also remove all doubt
as to whether it, too, was unintended.
-- 
In-Real-Life: Chris Torek, Lawrence Berkeley Lab CSE/EE (+1 415 486 5427)
Berkeley, CA		Domain:	torek@ee.lbl.gov