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From: keesan@bbncc5.UUCP (Morris M. Keesan)
Newsgroups: net.lang.c
Subject: Re: c programming style - READ THIS
Message-ID: <247@bbncc5.UUCP>
Date: Mon, 29-Jul-85 10:44:52 EDT
Article-I.D.: bbncc5.247
Posted: Mon Jul 29 10:44:52 1985
Date-Received: Wed, 31-Jul-85 03:18:51 EDT
References: <11570@brl-tgr.ARPA> <935@teddy.UUCP> <1286@uwmacc.UUCP> <2439@sun.uucp> <734@lsuc.UUCP>
Reply-To: keesan@bbncc5.UUCP (Morris M. Keesan)
Organization: Bolt Beranek and Newman, Cambridge, MA
Lines: 19
Keywords: RTM
Summary: a++ is equivalent to a+=1

In article <734@lsuc.UUCP> dave@lsuc.UUCP (David Sherman) writes:
>In article <2439@sun.uucp> guy@sun.uucp (Guy Harris) writes:
>||	2) "++a" and "a += 1" are completely equivalent expressions.
>
>Well, almost. On at least some systems, "a++" won't work if a is
>float, while "a += 1" will add 1.0 to a.

Those systems are buggy.  The C compiler for the BBN C/70 used to not support
++ and -- on floats, because the compiler maintainer said they were
"nonsensical".  When I inherited the compiler, I added code to the first pass
which would convert "++a" to "a+=1" for floating a.  From the C Reference
Manual, section 7.2 (p. 187, K&R):  "The expression ++x is equivalent to x+=1.
See the discussions of addition and assignment operators for information on
conversions."  The "usual arithmetic conversions" in this case cause "a += 1"
to be equivalent to "a += 1.0".
-- 
Morris M. Keesan
keesan@bbn-unix.ARPA
{decvax,ihnp4,etc.}!bbncca!keesan