Re: [boost] [Math] boost::math::signbit returns false for -NAN

16 Mar 2009


      Ping?
Regards Hartmut
...
-----Original Message-----
From: Hartmut Kaiser [mailto:hartmut.kaiser@gmail.com]
Sent: Wednesday, March 11, 2009 8:35 AM
To: 'boost@lists.boost.org'
Cc: 'John Maddock'
Subject: [Math] boost::math::signbit returns false for -NAN
Hi all,
the boost::math::signbit function in trunk fails for an argument of -
NAN.
#include <boost/math/special_functions/sign.hpp>
int main()
{
    using boost::math::signbit;
    BOOST_ASSERT(signbit(-std::numeric_limits<double>::quiet_NaN()));
    return 0;
}
I'd expect to get a '1' back, but the function returns zero and the
assertion fails. I know it worked while using Jon Rade's floating point
utilities library from the vault. Does this have been integrated?
Regards Hartmut