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From: comeau@ditka.Chicago.COM (Greg Comeau)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: Compiler code (was a flame fest)
Message-ID: <37302@ditka.Chicago.COM>
Date: 23 Apr 91 05:09:47 GMT
References: <1991Apr17.180342.25312@engin.umich.edu> <1991Apr18.122054.13695@athena.mit.edu> <1991Apr18.212939.3461@kessner.denver.co.us>
Sender: comeau@ditka.Chicago.COM (Greg Comeau)
Reply-To: comeau@csanta.attmail.com (Greg Comeau)
Organization: Comeau Computing
Lines: 21

In article <1991Apr18.212939.3461@kessner.denver.co.us> david@kessner.denver.co.us (David Kessner) writes:
>In article <1991Apr18.122054.13695@athena.mit.edu> amgreene@athena.mit.edu (Andrew Marc Greene) writes:
>>  int n = 4; (++n) * (--n);
>Humph.  The answer is 16.
>The pre-operators (--n ++n) mean "evaluate these expressions before anything
>else".  So the above statement is the same as:
>	n=n+1; 	n=n-1; 	?? = n * n;
>Try it.

Not quite.  First, C has some liberties in it's evaluation of some
expressions.  Second, exactly when side-effects take place in a given
expression is undefined.

Bottom line: 16 *might* work for your compiler, but needn't.

- Greg
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