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From: bright@dataio.Data-IO.COM (Walter Bright)
Newsgroups: comp.lang.c
Subject: Re: Style [++i vs i++]
Message-ID: <1324@dataio.Data-IO.COM>
Date: Wed, 1-Jul-87 13:07:50 EDT
Article-I.D.: dataio.1324
Posted: Wed Jul  1 13:07:50 1987
Date-Received: Thu, 2-Jul-87 07:06:07 EDT
References: <17310@amdcad.AMD.COM> <246@hubcap.UUCP>
Reply-To: bright@dataio.UUCP (Walter Bright)
Organization: Data I/O - FutureNet Corp., Redmond, WA
Lines: 23

In article <246@hubcap.UUCP< beede@hubcap.UUCP (Mike Beede) writes:
<in article <17310@amdcad.AMD.COM<, tim@amdcad.AMD.COM (Tim Olson) says:
<< [ question: use ++i or i++ when only side-effect is desired ]
<Just an observation: all expressions in C return a value.  Thus, every
<``naked'' expression involves throwing a value away (++i; AND i++;).  There
<is no reason a compiler needs to generate code differently for i++; and
<++i; if that is the entire expression (and statement).
<
<Maybe some people familiar with the internals of C compilers could comment
<on this--it may be easier to generate different code for these cases.

I speak for Datalight C (I wrote it):

	(++i) is always converted to (i += 1) by the parser.

	(i++) is converted to (i += 1) if the value of the expression
	is not used.

Therefore, the following all produce identical generated code:

	++i;
	i++;
	i += 1;