1 | // Special functions -*- C++ -*- |
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2 | |

3 | // Copyright (C) 2006-2018 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 tr1/special_function_util.h |

26 | * This is an internal header file, included by other library headers. |

27 | * Do not attempt to use it directly. @headername{tr1/cmath} |

28 | */ |

29 | |

30 | // |

31 | // ISO C++ 14882 TR1: 5.2 Special functions |

32 | // |

33 | |

34 | // Written by Edward Smith-Rowland based on numerous mathematics books. |

35 | |

36 | #ifndef _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H |

37 | #define _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H 1 |

38 | |

39 | namespace std _GLIBCXX_VISIBILITY(default) |

40 | { |

41 | _GLIBCXX_BEGIN_NAMESPACE_VERSION |

42 | |

43 | #if _GLIBCXX_USE_STD_SPEC_FUNCS |

44 | #elif defined(_GLIBCXX_TR1_CMATH) |

45 | namespace tr1 |

46 | { |

47 | #else |

48 | # error do not include this header directly, use <cmath> or <tr1/cmath> |

49 | #endif |

50 | namespace __detail |

51 | { |

52 | /// A class to encapsulate type dependent floating point |

53 | /// constants. Not everything will be able to be expressed as |

54 | /// type logic. |

55 | template<typename _Tp> |

56 | struct __floating_point_constant |

57 | { |

58 | static const _Tp __value; |

59 | }; |

60 | |

61 | |

62 | /// A structure for numeric constants. |

63 | template<typename _Tp> |

64 | struct __numeric_constants |

65 | { |

66 | /// Constant @f$ \pi @f$. |

67 | static _Tp __pi() throw() |

68 | { return static_cast<_Tp>(3.1415926535897932384626433832795029L); } |

69 | /// Constant @f$ \pi / 2 @f$. |

70 | static _Tp __pi_2() throw() |

71 | { return static_cast<_Tp>(1.5707963267948966192313216916397514L); } |

72 | /// Constant @f$ \pi / 3 @f$. |

73 | static _Tp __pi_3() throw() |

74 | { return static_cast<_Tp>(1.0471975511965977461542144610931676L); } |

75 | /// Constant @f$ \pi / 4 @f$. |

76 | static _Tp __pi_4() throw() |

77 | { return static_cast<_Tp>(0.7853981633974483096156608458198757L); } |

78 | /// Constant @f$ 1 / \pi @f$. |

79 | static _Tp __1_pi() throw() |

80 | { return static_cast<_Tp>(0.3183098861837906715377675267450287L); } |

81 | /// Constant @f$ 2 / \sqrt(\pi) @f$. |

82 | static _Tp __2_sqrtpi() throw() |

83 | { return static_cast<_Tp>(1.1283791670955125738961589031215452L); } |

84 | /// Constant @f$ \sqrt(2) @f$. |

85 | static _Tp __sqrt2() throw() |

86 | { return static_cast<_Tp>(1.4142135623730950488016887242096981L); } |

87 | /// Constant @f$ \sqrt(3) @f$. |

88 | static _Tp __sqrt3() throw() |

89 | { return static_cast<_Tp>(1.7320508075688772935274463415058723L); } |

90 | /// Constant @f$ \sqrt(\pi/2) @f$. |

91 | static _Tp __sqrtpio2() throw() |

92 | { return static_cast<_Tp>(1.2533141373155002512078826424055226L); } |

93 | /// Constant @f$ 1 / sqrt(2) @f$. |

94 | static _Tp __sqrt1_2() throw() |

95 | { return static_cast<_Tp>(0.7071067811865475244008443621048490L); } |

96 | /// Constant @f$ \log(\pi) @f$. |

97 | static _Tp __lnpi() throw() |

98 | { return static_cast<_Tp>(1.1447298858494001741434273513530587L); } |

99 | /// Constant Euler's constant @f$ \gamma_E @f$. |

100 | static _Tp __gamma_e() throw() |

101 | { return static_cast<_Tp>(0.5772156649015328606065120900824024L); } |

102 | /// Constant Euler-Mascheroni @f$ e @f$ |

103 | static _Tp __euler() throw() |

104 | { return static_cast<_Tp>(2.7182818284590452353602874713526625L); } |

105 | }; |

106 | |

107 | |

108 | #if _GLIBCXX_USE_C99_MATH && !_GLIBCXX_USE_C99_FP_MACROS_DYNAMIC |

109 | |

110 | /// This is a wrapper for the isnan function. Otherwise, for NaN, |

111 | /// all comparisons result in false. If/when we build a std::isnan |

112 | /// out of intrinsics, this will disappear completely in favor of |

113 | /// std::isnan. |

114 | template<typename _Tp> |

115 | inline bool __isnan(_Tp __x) |

116 | { return std::isnan(__x); } |

117 | |

118 | #else |

119 | |

120 | template<typename _Tp> |

121 | inline bool __isnan(const _Tp __x) |

122 | { return __builtin_isnan(__x); } |

123 | |

124 | template<> |

125 | inline bool __isnan<float>(float __x) |

126 | { return __builtin_isnanf(__x); } |

127 | |

128 | template<> |

129 | inline bool __isnan<long double>(long double __x) |

130 | { return __builtin_isnanl(__x); } |

131 | |

132 | #endif |

133 | } // namespace __detail |

134 | #if ! _GLIBCXX_USE_STD_SPEC_FUNCS && defined(_GLIBCXX_TR1_CMATH) |

135 | } // namespace tr1 |

136 | #endif |

137 | |

138 | _GLIBCXX_END_NAMESPACE_VERSION |

139 | } |

140 | |

141 | #endif // _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H |

142 | |

143 |