Re: [boost] [serialization] facets for non-finite numbers

From: Johan RÃ¥de (rade_at_[hidden])
Date: 2006-08-17 11:11:04

Hubert Holin wrote:

> *Negative* Not-A-Number? What is such a beast,

According to the IEEE 754 standard there is such a beast.
According the C99 standard, negative NaN (not-a-number) should be 
represented as "-nan" in text streams.

Negative NaN is simply a naN with a binary representation where the sign 
bit is 1.
There is no mathematical interpretation.

The expression -std::numeric_limits<T>::quiet_nan() gives you a negative 
NaN.

> and what should  it be used for?

No idea.

--Johan RÃ¥de