ceph/src/boost/boost/spirit/home/support/detail/sign.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 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(SPIRIT_SIGN_MAR_11_2009_0734PM)
  10 #define SPIRIT_SIGN_MAR_11_2009_0734PM
  11
  12 #if defined(_MSC_VER)
  13 #pragma once
  14 #endif
  15
  16 #include <boost/config/no_tr1/cmath.hpp>
  17 #include <boost/version.hpp>
  18 #if BOOST_VERSION < 104000
  19 #include <boost/spirit/home/support/detail/math/fpclassify.hpp>
  20 #include <boost/spirit/home/support/detail/math/signbit.hpp>
  21 #else
  22 #include <boost/math/special_functions/fpclassify.hpp>
  23 #include <boost/math/special_functions/sign.hpp>
  24 #endif
  25
  26 namespace boost { namespace spirit { namespace detail
  27 {
  28 #if BOOST_VERSION < 104000
  29     // signbit(-NAN) is broken for versions of Boost earlier than 1.40.0
  30     // This routine has been taken and adapted from Johan Rade's fp_traits
  31     // library
  32     template<typename T>
  33     inline bool (signbit)(T x)
  34     {
  35         return (boost::spirit::math::signbit)(x);
  36     }
  37
  38     template<typename T>
  39     inline T (changesign)(T x)
  40     {
  41         return (boost::spirit::math::changesign)(x);
  42     }
  43 #else
  44     template<typename T>
  45     inline bool (signbit)(T x)
  46     {
  47         return (boost::math::signbit)(x) ? true : false;
  48     }
  49
  50     // This routine has been taken and adapted from Johan Rade's fp_traits
  51     // library
  52     template<typename T>
  53     inline T (changesign)(T x)
  54     {
  55 #if defined(BOOST_MATH_USE_STD_FPCLASSIFY) && !defined(BOOST_MATH_DISABLE_STD_FPCLASSIFY)
  56         return -x;
  57 #else
  58         typedef typename math::detail::fp_traits<T>::type traits_type;
  59
  60         typename traits_type::bits a;
  61         traits_type::get_bits(x, a);
  62         a ^= traits_type::sign;
  63         traits_type::set_bits(x, a);
  64         return x;
  65 #endif
  66     }
  67 #endif
  68
  69 }}}
  70
  71 #endif