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>
T(changesign)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
72