Re: [boost] Optimized portable isnan, isfinite, fpclassify etc

Johan Råde wrote:

3. Your <limits> header is a bit funny. numeric_limits<T>::quiet_NaN() returns a NaN with the signbit set. This triggered the assertion.

You need to allow for the possibility that the sign bit is set anyway.

(Does it matter? Maybe. According to C99, positive NaN should be written to text files as "nan" or "+nan" and negative NaN as "-nan". And this will probably be part of C++0x as well.)

C++ doesn't guarentee any particular format for printing NaN's or Infinities :-( John.