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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: >< swap operator
Date: Tue, 14 Aug 2018 10:46:06 -0700
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David Brown <david.brown@hesbynett.no> writes:
> On 14/08/18 16:50, bart4858@gmail.com wrote:
>> How about just swap(x,y) then you don't need to explain what >< means.
>
> Or if you don't need to stick to C syntax:
>
> 	x, y = y, x

The problem is, that *is* C syntax.  Due to the low precedence of the
comma operator, it's equivalent to

    x, (y = y), x

This:

    (x, y) = (y, x)

is also valid C syntax, but it's a constraint violation because (x, y)
is not an lvalue (and the value of y on the RHS would be discarded
anyway).

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"