Re: Getting greatest decimal accuracy out of G_PI

[Robert Pearce <rob bdt-home demon co uk>]

Hi Sergei,

On Fri, 2 Feb 2007 16:14:09 -0800 (PST) you wrote:
> You can still use explicit cast, i.e.
> 
> ((long double)G_PI)
> 
> , can't you ? Even without the trail 'l' you have correctly suggested to
> add.

You can, but would it work? AIUI the C standard only requires that to result in a long double type - it's perfectly valid (and may even be required) for the compiler to treat G_PI as a normal double first, thus losing the precision, then convert that result to a long double. The trailing 'l' instructs the compiler to treat it as a long double while compiling, thus retaining as much precision as it can.