Re: [9fans] kenc: casting expression to void not ignored

[Pietro Gagliardi <pietro10@mac.com>]

I forgot to mention this is with the -w option; I found that turning  
it off also hid warnings I wanted to keep.

On Jun 29, 2008, at 9:53 AM, Pietro Gagliardi wrote:

> Hello. I have a simple push macro for a stack machine interpreter.  
> It looks like this:
>
> 	#define push(s) ((void)(((stackptr >= (stack + stacksize)) ?  
> growstack() : (void)0), (*stackptr++ = errcheck(s))))
>
> Does this boggle the mind? It's very simple: it checks for stack  
> overflow and makes the stack bigger if so, then checks to see if s,  
> a double, is NaN or ±Inf, and finally pushes it onto the stack if  
> not (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 of the operation? Thanks.
>
>