Re: [boost] [format] - exponential format, NaN and infinity

From: Stephan Tolksdorf (andorxor_at_[hidden])
Date: 2007-03-15 09:24:48

Johan RÃ¥de wrote:
> The floating_point_utilities library solves this problem.
> See the documentation of the header nonfinite_num_facets.hpp.
> 
> The library also provides portable implementations of fpclassify, isnan, 
> signbit etc.

Hi Johan,

What do you think about using the platform signbit and copysign if 
available (in TR1, C99, MSVC, ...)? There is a chance that the compiler 
optimizes the builtins better than expressions only using arithmetic 
primitives. I realize that testing the availability of copysign or 
copysign_ is probably difficult to do in the headers only, but for a 
subset of platforms it should be feasible.

Regards,
   Stephan