Paul D. Anderson:

>the coefficient and sign fields can be used as a "payload" for the NaN, 
>containing diagnostic information, etc.<

They are the tagged NaNs. Do you know of a possible usage of them? :-)


> And, according to the General Decimal Arithmetic Specification 
> (http://speleotrove.com/decimal) comparing NaN with any number, including 
> another NaN, will never return true.<

(Note: I am not proposing of introducing "== nan" in D, that enhancement 
request is just about the "is" operator).
There are situations where you want to know if a number is any NaN (or if it's 
specifically the NaN used by D to initialize floats/reals/doubles). The 
std.math.isNaN() function is useful.

Bye,
bearophile

Reply via email to