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Re: GURU NEEDED : macro SQUARE(x) for any type x


From: Hans Vlems
Subject: Re: GURU NEEDED : macro SQUARE(x) for any type x
Date: Fri, 14 Jan 2011 00:14:13 -0800 (PST)
User-agent: G2/1.0

On 14 jan, 08:15, luser- -droog <mijo...@yahoo.com> wrote:
> On Jan 14, 12:46 am, bolega <gnuist...@gmail.com> wrote:
>
>
>
>
>
> > Basically, I have spent a few hours experimenting and searching on the
> > comp.lang.c/c++
>
> > Let me use SQR for brevity and saving line
>
> > Here are progressively refined macros :
>
> > #define SQR(x) ((x)*(x))
>
> > #define SQR(x) ({typedef xtype=x; xtype xval=x; xval*xval})  // NOTE,
> > closure or {} inside () is a valid idea in C, and thus no return is
> > needed.
>
> > this macro is given in several posts like
>
> >http://groups.google.com/group/comp.lang.lisp/browse_frm/thread/38ef2...
>
> > there is a problem with typedef
>
> > Bolega
>
> OIK
>
> #define SQR(x) pow((x),2)
> or
> #define SQR(x) exp(2 * log(x))- Tekst uit oorspronkelijk bericht niet 
> weergeven -
>
> - Tekst uit oorspronkelijk bericht weergeven -

What happens for x=0 in the second example?


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