Re: [boost] The meaning of -nan (was [serialization] facets for non-finite numbers)

From: Deane Yang (deane_yang_at_[hidden])
Date: 2006-08-17 12:11:57

Paul A Bristow wrote:
> |  Paul Bristow wrote
> |  > That is indeed the *intention* - but entirely USER-DEFINED 
> |  and with NO MATH
> |  > MEANING.
> |  > 
> |  > NaNs are never > < or == anyway?
> |  
> |  But it tells you where how you got there doesnt it?
> 
> Maybe - but this is getting OT - the topic was Octonionic Not-A-Numbers ;-)
> 

Is this really off-topic? I've seen everyone assert that -nan has no 
mathematical meaning. Does this mean that there is no pfficial 
specification (whether it is "mathematically meaningful" or not) of how 
a -nan can arise as a result of an arithmetic operation?