isnan() with gcc 3.2.2 on FreeBSD 5.0-C

David Leimbach leimy2k at
Mon Mar 31 04:46:05 PST 2003

On Monday, March 31, 2003, at 02:49 AM, Stefan Farfeleder wrote:

> The isnan() macro is a new feature of C99 and thus not (yet) part of
> C++.  Nevertheless you can use -D_GLIBCPP_USE_C99 to include this and

There may be no guarantee that any new parts of C99 ever make it into 
the C++

C++ has always been a superset of a subset of C :).  That is to say 
that C is not
100% contained within C++.

This has gotten to be more of a problem since
the C99 standard has added things the C++ already had as well such as
_Complex and the very weird tgmath.h header that seemingly cannot even 
written with standard C. [I have seen the version that came with RedHat 
linux and
it involved a bunch of gcc specific code].

Anyway... Its a real world problem now and the errors people are seeing 
are due to
the fact that g++-3.x is more standards compliant than 2.x was.


More information about the freebsd-questions mailing list