ceph/src/boost/libs/spirit/include/boost/spirit/home/support/detail/math/signbit.hpp

   1 // signbit.hpp
   2
   3 #ifndef BOOST_SPIRIT_MATH_SIGNBIT_HPP
   4 #define BOOST_SPIRIT_MATH_SIGNBIT_HPP
   5
   6 // Copyright (c) 2006 Johan Rade
   7
   8 // Distributed under the Boost Software License, Version 1.0.
   9 // (See accompanying file LICENSE_1_0.txt
  10 // or copy at http://www.boost.org/LICENSE_1_0.txt)
  11
  12 #if defined(_MSC_VER)
  13 #pragma once
  14 #endif
  15
  16 #include <boost/spirit/home/support/detail/math/detail/fp_traits.hpp>
  17
  18 namespace boost {
  19 namespace spirit {
  20 namespace math {
  21
  22 //------------------------------------------------------------------------------
  23
  24 template<class T> bool (signbit)(T x)
  25 {
  26     typedef BOOST_DEDUCED_TYPENAME detail::fp_traits<T>::type traits;
  27     traits::init();
  28
  29     BOOST_DEDUCED_TYPENAME traits::bits a;
  30     traits::get_bits(x,a);
  31     a &= traits::sign;
  32     return a != 0;
  33 }
  34
  35 //------------------------------------------------------------------------------
  36
  37 namespace detail {
  38
  39     template<class T> T copysign_impl(T x, T y)
  40     {
  41         typedef BOOST_DEDUCED_TYPENAME fp_traits<T>::type traits;
  42         traits::init();
  43
  44         BOOST_DEDUCED_TYPENAME traits::bits a;
  45         traits::get_bits(x,a);
  46         a &= ~traits::sign;
  47
  48         BOOST_DEDUCED_TYPENAME traits::bits b;
  49         traits::get_bits(y,b);
  50         b &= traits::sign;
  51
  52         traits::set_bits(x,a|b);
  53         return x;
  54     }
  55 }
  56
  57 inline float (copysign)(float x, float y)      // magnitude of x and sign of y
  58 {
  59     return detail::copysign_impl(x,y);
  60 }
  61
  62 inline double (copysign)(double x, double y)
  63 {
  64     return detail::copysign_impl(x,y);
  65 }
  66
  67 inline long double (copysign)(long double x, long double y)
  68 {
  69     return detail::copysign_impl(x,y);
  70 }
  71
  72 //------------------------------------------------------------------------------
  73
  74 template<class T> T (changesign)(T x)
  75 {
  76     typedef BOOST_DEDUCED_TYPENAME detail::fp_traits<T>::type traits;
  77     traits::init();
  78
  79     BOOST_DEDUCED_TYPENAME traits::bits a;
  80     traits::get_bits(x,a);
  81     a ^= traits::sign;
  82     traits::set_bits(x,a);
  83     return x;
  84 }
  85
  86 //------------------------------------------------------------------------------
  87
  88 }   // namespace math
  89 }   // namespace spirit
  90 }   // namespace boost
  91
  92 #endif