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From: horne-scott@cs.yale.edu (Scott Horne)
Newsgroups: comp.lang.c
Subject: Re: Swapping two variables in place
Message-ID: <26310@cs.yale.edu>
Date: 23 Sep 90 02:23:46 GMT
References: <26101@shamash.cdc.com>
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In article <26101@shamash.cdc.com> awm@shamash.UUCP (Allan Magnuson) writes:
>There was a message a while back about not being able to create a good
>#define function to swap two variables.
>
>How about this one: #define swap(a,b) a^=b^=a^=b

I prefer

#define ___(_,__)(_^=__^=_^=__)

It's delightfully difficult to read, isn't it?  :-)  "Oh, that?  It swaps
variables.  Can't you tell?"  :-)

But it won't work on `float's and `double's, as `^' is defined only on
integral types.

					--Scott

-- 
Scott Horne                               ...!{harvard,cmcl2,decvax}!yale!horne
horne@cs.Yale.edu      SnailMail:  Box 7196 Yale Station, New Haven, CT   06520
203 436-1817                    Residence:  Rm 1817 Silliman College, Yale Univ
Uneasy lies the head that wears the _gao1 mao4zi_.