Mail Archives: djgpp/1998/04/23/08:31:14
In article <353F141B DOT 24547B62 AT usa DOT net> you wrote:
> I also noticed neither isnan() nor isnanf() appear to be ANSI or
> POSIX.
I don't think they can possibly be. After all, there's nothing that
would guarantee that there even _is_ such a thing as a NaN on every
possible platform. (But rumor has it that the requirement of such IEEE
754 compatibility may be added to the next of the ANSI C Standard,
nicknamed C9X).
> Are they widely supported? Or a Gnu extension?
Widely supported: yes, I'ld say (just checked on Linux, Solaris, DEC
Unix, DEC Ultrix, and SGI's IRIX). According to one of those systems'
man pages, it's defined by 'XPG4' (by X/Open, a Unix standardisation
effort). Certainly no GNU extension.
Generally, I'ld guess you'll find isnan() & friends on every system
with an IEEE 754 compatible floating point system.
--
Hans-Bernhard Broeker (broeker AT physik DOT rwth-aachen DOT de)
Even if all the snow were burnt, ashes would remain.
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