ceph/src/boost/boost/spirit/home/x3/support/numeric_utils/sign.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2014 Joel de Guzman
   3     Copyright (c) 2001-2011 Hartmut Kaiser
   4     http://spirit.sourceforge.net/
   5
   6     Distributed under the Boost Software License, Version 1.0. (See accompanying
   7     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   8 =============================================================================*/
   9 #if !defined(BOOST_SPIRIT_X3_SIGN_MAR_11_2009_0734PM)
  10 #define BOOST_SPIRIT_X3_SIGN_MAR_11_2009_0734PM
  11
  12 #include <boost/config/no_tr1/cmath.hpp>
  13 #include <boost/math/special_functions/fpclassify.hpp>
  14 #include <boost/math/special_functions/sign.hpp>
  15
  16 namespace boost { namespace spirit { namespace x3
  17 {
  18     template<typename T>
  19     inline bool (signbit)(T x)
  20     {
  21         return (boost::math::signbit)(x) ? true : false;
  22     }
  23
  24     // This routine has been taken and adapted from Johan Rade's fp_traits
  25     // library
  26     template<typename T>
  27     inline T (changesign)(T x)
  28     {
  29 #if defined(BOOST_MATH_USE_STD_FPCLASSIFY) && !defined(BOOST_MATH_DISABLE_STD_FPCLASSIFY)
  30         return -x;
  31 #else
  32         typedef typename math::detail::fp_traits<T>::type traits_type;
  33
  34         typename traits_type::bits a;
  35         traits_type::get_bits(x, a);
  36         a ^= traits_type::sign;
  37         traits_type::set_bits(x, a);
  38         return x;
  39 #endif
  40     }
  41
  42 }}}
  43
  44 #endif