From mboxrd@z Thu Jan  1 00:00:00 1970
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From: Pietro Gagliardi <pietro10@mac.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
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Date: Sun, 29 Jun 2008 09:53:39 -0400
Subject: [9fans] kenc: casting expression to void not ignored
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Hello. I have a simple push macro for a stack machine interpreter. It =20=

looks like this:

	#define push(s) ((void)(((stackptr >=3D (stack + stacksize)) ? =20=

growstack() : (void)0), (*stackptr++ =3D errcheck(s))))

Does this boggle the mind? It's very simple: it checks for stack =20
overflow and makes the stack bigger if so, then checks to see if s, a =20=

double, is NaN or =B1Inf, and finally pushes it onto the stack if not =20=

(errcheck calls longjmp - how I wish I had try).

However, when I use the push macro, I get tons of warnings like this:

	warning: run.c:170 result of operation not used

Shouldn't the cast to void mean that I don't intend to use the result =20=

of the operation? Thanks.