Re: [boost] is_nan

From: Johan Råde (rade_at_[hidden])
Date: 2006-07-25 06:45:17

Johan Råde wrote:

> So the floating point number classification now goes like:
> 
> 1. Finite
> 1.1. Normalized finite
> 1.2. Denormalized finite
> 2. Infinity
> 2.1. Positive infinity
> 2.2. Negative infinity
> 3. Not-a-number
> 3.1. Quite not-a-number
> 3.2. Signalling not-a-number

I believe the term normal is more common nowadays than normalized or 
non-denormalized.
I believe the term subnormal is more common nowadays than denormalized.

So it would make sense to have the functions

   is_finite()
   is_normal()
   is_subnormal()

   is_infinity()
   is_plus_infinity()
   is_minus_infinity()

   is_nan()

and possibly

   is_quite_nan()
   is_signalling_nan()

The last two are tricky to implement though.

--Johan Råde