cmath 6.4 KB

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  1. // Math extensions -*- C++ -*-
  2. // Copyright (C) 2013-2015 Free Software Foundation, Inc.
  3. //
  4. // This file is part of the GNU ISO C++ Library. This library is free
  5. // software; you can redistribute it and/or modify it under the
  6. // terms of the GNU General Public License as published by the
  7. // Free Software Foundation; either version 3, or (at your option)
  8. // any later version.
  9. // This library is distributed in the hope that it will be useful,
  10. // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11. // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12. // GNU General Public License for more details.
  13. // Under Section 7 of GPL version 3, you are granted additional
  14. // permissions described in the GCC Runtime Library Exception, version
  15. // 3.1, as published by the Free Software Foundation.
  16. // You should have received a copy of the GNU General Public License and
  17. // a copy of the GCC Runtime Library Exception along with this program;
  18. // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
  19. // <http://www.gnu.org/licenses/>.
  20. /** @file ext/cmath
  21. * This file is a GNU extension to the Standard C++ Library.
  22. */
  23. #ifndef _EXT_CMATH
  24. #define _EXT_CMATH 1
  25. #pragma GCC system_header
  26. #if __cplusplus < 201103L
  27. # include <bits/c++0x_warning.h>
  28. #else
  29. #include <cmath>
  30. #include <type_traits>
  31. namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  32. {
  33. _GLIBCXX_BEGIN_NAMESPACE_VERSION
  34. // A class for math constants.
  35. template<typename _RealType>
  36. struct __math_constants
  37. {
  38. static_assert(std::is_floating_point<_RealType>::value,
  39. "template argument not a floating point type");
  40. // Constant @f$ \pi @f$.
  41. static constexpr _RealType __pi = 3.1415926535897932384626433832795029L;
  42. // Constant @f$ \pi / 2 @f$.
  43. static constexpr _RealType __pi_half = 1.5707963267948966192313216916397514L;
  44. // Constant @f$ \pi / 3 @f$.
  45. static constexpr _RealType __pi_third = 1.0471975511965977461542144610931676L;
  46. // Constant @f$ \pi / 4 @f$.
  47. static constexpr _RealType __pi_quarter = 0.7853981633974483096156608458198757L;
  48. // Constant @f$ \sqrt(\pi / 2) @f$.
  49. static constexpr _RealType __root_pi_div_2 = 1.2533141373155002512078826424055226L;
  50. // Constant @f$ 1 / \pi @f$.
  51. static constexpr _RealType __one_div_pi = 0.3183098861837906715377675267450287L;
  52. // Constant @f$ 2 / \pi @f$.
  53. static constexpr _RealType __two_div_pi = 0.6366197723675813430755350534900574L;
  54. // Constant @f$ 2 / \sqrt(\pi) @f$.
  55. static constexpr _RealType __two_div_root_pi = 1.1283791670955125738961589031215452L;
  56. // Constant Euler's number @f$ e @f$.
  57. static constexpr _RealType __e = 2.7182818284590452353602874713526625L;
  58. // Constant @f$ 1 / e @f$.
  59. static constexpr _RealType __one_div_e = 0.36787944117144232159552377016146087L;
  60. // Constant @f$ \log_2(e) @f$.
  61. static constexpr _RealType __log2_e = 1.4426950408889634073599246810018921L;
  62. // Constant @f$ \log_10(e) @f$.
  63. static constexpr _RealType __log10_e = 0.4342944819032518276511289189166051L;
  64. // Constant @f$ \ln(2) @f$.
  65. static constexpr _RealType __ln_2 = 0.6931471805599453094172321214581766L;
  66. // Constant @f$ \ln(3) @f$.
  67. static constexpr _RealType __ln_3 = 1.0986122886681096913952452369225257L;
  68. // Constant @f$ \ln(10) @f$.
  69. static constexpr _RealType __ln_10 = 2.3025850929940456840179914546843642L;
  70. // Constant Euler-Mascheroni @f$ \gamma_E @f$.
  71. static constexpr _RealType __gamma_e = 0.5772156649015328606065120900824024L;
  72. // Constant Golden Ratio @f$ \phi @f$.
  73. static constexpr _RealType __phi = 1.6180339887498948482045868343656381L;
  74. // Constant @f$ \sqrt(2) @f$.
  75. static constexpr _RealType __root_2 = 1.4142135623730950488016887242096981L;
  76. // Constant @f$ \sqrt(3) @f$.
  77. static constexpr _RealType __root_3 = 1.7320508075688772935274463415058724L;
  78. // Constant @f$ \sqrt(5) @f$.
  79. static constexpr _RealType __root_5 = 2.2360679774997896964091736687312762L;
  80. // Constant @f$ \sqrt(7) @f$.
  81. static constexpr _RealType __root_7 = 2.6457513110645905905016157536392604L;
  82. // Constant @f$ 1 / \sqrt(2) @f$.
  83. static constexpr _RealType __one_div_root_2 = 0.7071067811865475244008443621048490L;
  84. };
  85. // And the template definitions for the constants.
  86. template<typename _RealType>
  87. constexpr _RealType __math_constants<_RealType>::__pi;
  88. template<typename _RealType>
  89. constexpr _RealType __math_constants<_RealType>::__pi_half;
  90. template<typename _RealType>
  91. constexpr _RealType __math_constants<_RealType>::__pi_third;
  92. template<typename _RealType>
  93. constexpr _RealType __math_constants<_RealType>::__pi_quarter;
  94. template<typename _RealType>
  95. constexpr _RealType __math_constants<_RealType>::__root_pi_div_2;
  96. template<typename _RealType>
  97. constexpr _RealType __math_constants<_RealType>::__one_div_pi;
  98. template<typename _RealType>
  99. constexpr _RealType __math_constants<_RealType>::__two_div_pi;
  100. template<typename _RealType>
  101. constexpr _RealType __math_constants<_RealType>::__two_div_root_pi;
  102. template<typename _RealType>
  103. constexpr _RealType __math_constants<_RealType>::__e;
  104. template<typename _RealType>
  105. constexpr _RealType __math_constants<_RealType>::__one_div_e;
  106. template<typename _RealType>
  107. constexpr _RealType __math_constants<_RealType>::__log2_e;
  108. template<typename _RealType>
  109. constexpr _RealType __math_constants<_RealType>::__log10_e;
  110. template<typename _RealType>
  111. constexpr _RealType __math_constants<_RealType>::__ln_2;
  112. template<typename _RealType>
  113. constexpr _RealType __math_constants<_RealType>::__ln_3;
  114. template<typename _RealType>
  115. constexpr _RealType __math_constants<_RealType>::__ln_10;
  116. template<typename _RealType>
  117. constexpr _RealType __math_constants<_RealType>::__gamma_e;
  118. template<typename _RealType>
  119. constexpr _RealType __math_constants<_RealType>::__phi;
  120. template<typename _RealType>
  121. constexpr _RealType __math_constants<_RealType>::__root_2;
  122. template<typename _RealType>
  123. constexpr _RealType __math_constants<_RealType>::__root_3;
  124. template<typename _RealType>
  125. constexpr _RealType __math_constants<_RealType>::__root_5;
  126. template<typename _RealType>
  127. constexpr _RealType __math_constants<_RealType>::__root_7;
  128. template<typename _RealType>
  129. constexpr _RealType __math_constants<_RealType>::__one_div_root_2;
  130. _GLIBCXX_END_NAMESPACE_VERSION
  131. } // namespace __gnu_cxx
  132. #endif // C++11
  133. #endif // _EXT_CMATH