libstdc++-v3/include/std/numbers

   1 // <numbers> -*- C++ -*-
   2
   3 // Copyright (C) 2019-2024 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /** @file include/numbers
  26  *  This is a Standard C++ Library header.
  27  */
  28
  29 #ifndef _GLIBCXX_NUMBERS
  30 #define _GLIBCXX_NUMBERS 1
  31
  32 #pragma GCC system_header
  33
  34 #define __glibcxx_want_math_constants
  35 #include <bits/version.h>
  36
  37 #ifdef __cpp_lib_math_constants // C++ >= 20
  38
  39 #include <type_traits>
  40
  41 namespace std _GLIBCXX_VISIBILITY(default)
  42 {
  43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  44
  45 /** @defgroup math_constants Mathematical constants
  46  *  @ingroup numerics
  47  *  @{
  48  */
  49
  50 /// Namespace for mathematical constants
  51 namespace numbers
  52 {
  53
  54   /// @cond undocumented
  55   template<typename _Tp>
  56     using _Enable_if_floating = enable_if_t<is_floating_point_v<_Tp>, _Tp>;
  57   /// @endcond
  58
  59   /// e
  60   template<typename _Tp>
  61     inline constexpr _Tp e_v
  62       = _Enable_if_floating<_Tp>(2.718281828459045235360287471352662498L);
  63
  64   /// log_2 e
  65   template<typename _Tp>
  66     inline constexpr _Tp log2e_v
  67       = _Enable_if_floating<_Tp>(1.442695040888963407359924681001892137L);
  68
  69   /// log_10 e
  70   template<typename _Tp>
  71     inline constexpr _Tp log10e_v
  72       = _Enable_if_floating<_Tp>(0.434294481903251827651128918916605082L);
  73
  74   /// pi
  75   template<typename _Tp>
  76     inline constexpr _Tp pi_v
  77       = _Enable_if_floating<_Tp>(3.141592653589793238462643383279502884L);
  78
  79   /// 1/pi
  80   template<typename _Tp>
  81     inline constexpr _Tp inv_pi_v
  82       = _Enable_if_floating<_Tp>(0.318309886183790671537767526745028724L);
  83
  84   /// 1/sqrt(pi)
  85   template<typename _Tp>
  86     inline constexpr _Tp inv_sqrtpi_v
  87       = _Enable_if_floating<_Tp>(0.564189583547756286948079451560772586L);
  88
  89   /// log_e 2
  90   template<typename _Tp>
  91     inline constexpr _Tp ln2_v
  92       = _Enable_if_floating<_Tp>(0.693147180559945309417232121458176568L);
  93
  94   /// log_e 10
  95   template<typename _Tp>
  96     inline constexpr _Tp ln10_v
  97       = _Enable_if_floating<_Tp>(2.302585092994045684017991454684364208L);
  98
  99   /// sqrt(2)
 100   template<typename _Tp>
 101     inline constexpr _Tp sqrt2_v
 102       = _Enable_if_floating<_Tp>(1.414213562373095048801688724209698079L);
 103
 104   /// sqrt(3)
 105   template<typename _Tp>
 106     inline constexpr _Tp sqrt3_v
 107       = _Enable_if_floating<_Tp>(1.732050807568877293527446341505872367L);
 108
 109   /// 1/sqrt(3)
 110   template<typename _Tp>
 111     inline constexpr _Tp inv_sqrt3_v
 112       = _Enable_if_floating<_Tp>(0.577350269189625764509148780501957456L);
 113
 114   /// The Euler-Mascheroni constant
 115   template<typename _Tp>
 116     inline constexpr _Tp egamma_v
 117       = _Enable_if_floating<_Tp>(0.577215664901532860606512090082402431L);
 118
 119   /// The golden ratio, (1+sqrt(5))/2
 120   template<typename _Tp>
 121     inline constexpr _Tp phi_v
 122       = _Enable_if_floating<_Tp>(1.618033988749894848204586834365638118L);
 123
 124   inline constexpr double e = e_v<double>;
 125   inline constexpr double log2e = log2e_v<double>;
 126   inline constexpr double log10e = log10e_v<double>;
 127   inline constexpr double pi = pi_v<double>;
 128   inline constexpr double inv_pi = inv_pi_v<double>;
 129   inline constexpr double inv_sqrtpi = inv_sqrtpi_v<double>;
 130   inline constexpr double ln2 = ln2_v<double>;
 131   inline constexpr double ln10 = ln10_v<double>;
 132   inline constexpr double sqrt2 = sqrt2_v<double>;
 133   inline constexpr double sqrt3 = sqrt3_v<double>;
 134   inline constexpr double inv_sqrt3 = inv_sqrt3_v<double>;
 135   inline constexpr double egamma = egamma_v<double>;
 136   inline constexpr double phi = phi_v<double>;
 137
 138 #define __glibcxx_numbers(TYPE, SUFFIX) \
 139   /* e */                                               \
 140   template<>                                            \
 141     inline constexpr TYPE e_v<TYPE>                     \
 142       = 2.718281828459045235360287471352662498##SUFFIX; \
 143                                                         \
 144   /* log_2 e */                                         \
 145   template<>                                            \
 146     inline constexpr TYPE log2e_v<TYPE>                 \
 147       = 1.442695040888963407359924681001892137##SUFFIX; \
 148                                                         \
 149   /* log_10 e */                                        \
 150   template<>                                            \
 151     inline constexpr TYPE log10e_v<TYPE>                \
 152       = 0.434294481903251827651128918916605082##SUFFIX; \
 153                                                         \
 154   /* pi */                                              \
 155   template<>                                            \
 156     inline constexpr TYPE pi_v<TYPE>                    \
 157       = 3.141592653589793238462643383279502884##SUFFIX; \
 158                                                         \
 159   /* 1/pi */                                            \
 160   template<>                                            \
 161     inline constexpr TYPE inv_pi_v<TYPE>                \
 162       = 0.318309886183790671537767526745028724##SUFFIX; \
 163                                                         \
 164   /* 1/sqrt(pi) */                                      \
 165   template<>                                            \
 166     inline constexpr TYPE inv_sqrtpi_v<TYPE>            \
 167       = 0.564189583547756286948079451560772586##SUFFIX; \
 168                                                         \
 169   /* log_e 2 */                                         \
 170   template<>                                            \
 171     inline constexpr TYPE ln2_v<TYPE>                   \
 172       = 0.693147180559945309417232121458176568##SUFFIX; \
 173                                                         \
 174   /* log_e 10 */                                        \
 175   template<>                                            \
 176     inline constexpr TYPE ln10_v<TYPE>                  \
 177       = 2.302585092994045684017991454684364208##SUFFIX; \
 178                                                         \
 179   /* sqrt(2) */                                         \
 180   template<>                                            \
 181     inline constexpr TYPE sqrt2_v<TYPE>                 \
 182       = 1.414213562373095048801688724209698079##SUFFIX; \
 183                                                         \
 184   /* sqrt(3) */                                         \
 185   template<>                                            \
 186     inline constexpr TYPE sqrt3_v<TYPE>                 \
 187       = 1.732050807568877293527446341505872367##SUFFIX; \
 188                                                         \
 189   /* 1/sqrt(3) */                                       \
 190   template<>                                            \
 191     inline constexpr TYPE inv_sqrt3_v<TYPE>             \
 192       = 0.577350269189625764509148780501957456##SUFFIX; \
 193                                                         \
 194   /* The Euler-Mascheroni constant */                   \
 195   template<>                                            \
 196     inline constexpr TYPE egamma_v<TYPE>                \
 197       = 0.577215664901532860606512090082402431##SUFFIX; \
 198                                                         \
 199   /* The golden ratio, (1+sqrt(5))/2 */                 \
 200   template<>                                            \
 201     inline constexpr TYPE phi_v<TYPE>                   \
 202       = 1.618033988749894848204586834365638118##SUFFIX
 203
 204 #ifdef __STDCPP_FLOAT16_T__
 205 __glibcxx_numbers (_Float16, F16);
 206 #endif
 207
 208 #ifdef __STDCPP_FLOAT32_T__
 209 __glibcxx_numbers (_Float32, F32);
 210 #endif
 211
 212 #ifdef __STDCPP_FLOAT64_T__
 213 __glibcxx_numbers (_Float64, F64);
 214 #endif
 215
 216 #ifdef __STDCPP_FLOAT128_T__
 217 __glibcxx_numbers (_Float128, F128);
 218 #endif
 219
 220 #ifdef __STDCPP_BFLOAT128_T__
 221 __glibcxx_numbers (__gnu_cxx::__bfloat16_t, BF16);
 222 #endif
 223
 224 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
 225 __glibcxx_numbers (__float128, Q);
 226 #endif // USE_FLOAT128
 227
 228 #undef __glibcxx_numbers
 229
 230 } // namespace numbers
 231 /// @}
 232 _GLIBCXX_END_NAMESPACE_VERSION
 233 } // namespace std
 234
 235 #endif // __cpp_lib_math_constants
 236 #endif // _GLIBCXX_NUMBERS