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


From: luser- -droog
Subject: Re: GURU NEEDED : macro SQUARE(x) for any type x
Date: Thu, 13 Jan 2011 23:15:54 -0800 (PST)
User-agent: G2/1.0

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))


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