mingw/lib/gcc/mingw32/4.3.3/include/c++/tr1/special_function_util.h

   1 // Special functions -*- C++ -*-
   2
   3 // Copyright (C) 2006
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 /** @file tr1/special_function_util.h
  32  *  This is an internal header file, included by other library headers.
  33  *  You should not attempt to use it directly.
  34  */
  35
  36 //
  37 // ISO C++ 14882 TR1: 5.2  Special functions
  38 //
  39
  40 // Written by Edward Smith-Rowland based on numerous mathematics books.
  41
  42 #ifndef _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H
  43 #define _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H 1
  44
  45 namespace std
  46 {
  47 namespace tr1
  48 {
  49
  50   namespace __detail
  51   {
  52
  53     /// A class to encapsulate type dependent floating point
  54     /// constants.  Not everything will be able to be expressed as
  55     /// type logic.
  56     template<typename _Tp>
  57     struct __floating_point_constant
  58     {
  59       static const _Tp __value;
  60     };
  61
  62
  63     /// A structure for numeric constants.
  64     template<typename _Tp>
  65       struct __numeric_constants
  66       {
  67         ///  Constant @f$ \pi @f$.
  68         static _Tp __pi() throw()
  69         { return static_cast<_Tp>(3.1415926535897932384626433832795029L); }
  70         ///  Constant @f$ \pi / 2 @f$.
  71         static _Tp __pi_2() throw()
  72         { return static_cast<_Tp>(1.5707963267948966192313216916397514L); }
  73         ///  Constant @f$ \pi / 3 @f$.
  74         static _Tp __pi_3() throw()
  75         { return static_cast<_Tp>(1.0471975511965977461542144610931676L); }
  76         ///  Constant @f$ \pi / 4 @f$.
  77         static _Tp __pi_4() throw()
  78         { return static_cast<_Tp>(0.7853981633974483096156608458198757L); }
  79         ///  Constant @f$ 1 / \pi @f$.
  80         static _Tp __1_pi() throw()
  81         { return static_cast<_Tp>(0.3183098861837906715377675267450287L); }
  82         ///  Constant @f$ 2 / \sqrt(\pi) @f$.
  83         static _Tp __2_sqrtpi() throw()
  84         { return static_cast<_Tp>(1.1283791670955125738961589031215452L); }
  85         ///  Constant @f$ \sqrt(2) @f$.
  86         static _Tp __sqrt2() throw()
  87         { return static_cast<_Tp>(1.4142135623730950488016887242096981L); }
  88         ///  Constant @f$ \sqrt(3) @f$.
  89         static _Tp __sqrt3() throw()
  90         { return static_cast<_Tp>(1.7320508075688772935274463415058723L); }
  91         ///  Constant @f$ \sqrt(\pi/2) @f$.
  92         static _Tp __sqrtpio2() throw()
  93         { return static_cast<_Tp>(1.2533141373155002512078826424055226L); }
  94         ///  Constant @f$ 1 / sqrt(2) @f$.
  95         static _Tp __sqrt1_2() throw()
  96         { return static_cast<_Tp>(0.7071067811865475244008443621048490L); }
  97         ///  Constant @f$ \log(\pi) @f$.
  98         static _Tp __lnpi() throw()
  99         { return static_cast<_Tp>(1.1447298858494001741434273513530587L); }
 100         ///  Constant Euler's constant @f$ \gamma_E @f$.
 101         static _Tp __gamma_e() throw()
 102         { return static_cast<_Tp>(0.5772156649015328606065120900824024L); }
 103         ///  Constant Euler-Mascheroni @f$ e @f$
 104         static _Tp __euler() throw()
 105         { return static_cast<_Tp>(2.7182818284590452353602874713526625L); }
 106       };
 107
 108
 109 #if _GLIBCXX_USE_C99_MATH && !_GLIBCXX_USE_C99_FP_MACROS_DYNAMIC
 110
 111     /// This is a wrapper for the isnan function. Otherwise, for NaN,
 112     /// all comparisons result in false. If/when we build a std::isnan
 113     /// out of intrinsics, this will disappear completely in favor of
 114     /// std::isnan.
 115     template<typename _Tp>
 116     inline bool __isnan(const _Tp __x)
 117     {
 118       return std::isnan(__x);
 119     }
 120
 121 #else
 122
 123     template<typename _Tp>
 124     inline bool __isnan(const _Tp __x)
 125     {
 126       return __builtin_isnan(__x);
 127     }
 128
 129     template<>
 130     inline bool __isnan<float>(const float __x)
 131     {
 132       return __builtin_isnanf(__x);
 133     }
 134
 135     template<>
 136     inline bool __isnan<long double>(const long double __x)
 137     {
 138       return __builtin_isnanl(__x);
 139     }
 140
 141 #endif
 142
 143   } // namespace __detail
 144
 145 }
 146 }
 147
 148 #endif // _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H
 149