libstdc++
numbers
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1 // <numbers> -*- C++ -*-
2 
3 // Copyright (C) 2019-2021 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 #if __cplusplus > 201703L
35 
36 #include <type_traits>
37 
38 namespace std _GLIBCXX_VISIBILITY(default)
39 {
40 _GLIBCXX_BEGIN_NAMESPACE_VERSION
41 
42 /** @defgroup math_constants Mathematical constants
43  * @ingroup numerics
44  * @{
45  */
46 
47 /// Namespace for mathematical constants
48 namespace numbers
49 {
50 #define __cpp_lib_math_constants 201907L
51 
52  /// @cond undoc
53  template<typename _Tp>
54  using _Enable_if_floating = enable_if_t<is_floating_point_v<_Tp>, _Tp>;
55  /// @endcond
56 
57  /// e
58  template<typename _Tp>
59  inline constexpr _Tp e_v
60  = _Enable_if_floating<_Tp>(2.718281828459045235360287471352662498L);
61 
62  /// log_2 e
63  template<typename _Tp>
64  inline constexpr _Tp log2e_v
65  = _Enable_if_floating<_Tp>(1.442695040888963407359924681001892137L);
66 
67  /// log_10 e
68  template<typename _Tp>
69  inline constexpr _Tp log10e_v
70  = _Enable_if_floating<_Tp>(0.434294481903251827651128918916605082L);
71 
72  /// pi
73  template<typename _Tp>
74  inline constexpr _Tp pi_v
75  = _Enable_if_floating<_Tp>(3.141592653589793238462643383279502884L);
76 
77  /// 1/pi
78  template<typename _Tp>
79  inline constexpr _Tp inv_pi_v
80  = _Enable_if_floating<_Tp>(0.318309886183790671537767526745028724L);
81 
82  /// 1/sqrt(pi)
83  template<typename _Tp>
84  inline constexpr _Tp inv_sqrtpi_v
85  = _Enable_if_floating<_Tp>(0.564189583547756286948079451560772586L);
86 
87  /// log_e 2
88  template<typename _Tp>
89  inline constexpr _Tp ln2_v
90  = _Enable_if_floating<_Tp>(0.693147180559945309417232121458176568L);
91 
92  /// log_e 10
93  template<typename _Tp>
94  inline constexpr _Tp ln10_v
95  = _Enable_if_floating<_Tp>(2.302585092994045684017991454684364208L);
96 
97  /// sqrt(2)
98  template<typename _Tp>
99  inline constexpr _Tp sqrt2_v
100  = _Enable_if_floating<_Tp>(1.414213562373095048801688724209698079L);
101 
102  /// sqrt(3)
103  template<typename _Tp>
104  inline constexpr _Tp sqrt3_v
105  = _Enable_if_floating<_Tp>(1.732050807568877293527446341505872367L);
106 
107  /// 1/sqrt(3)
108  template<typename _Tp>
109  inline constexpr _Tp inv_sqrt3_v
110  = _Enable_if_floating<_Tp>(0.577350269189625764509148780501957456L);
111 
112  /// The Euler-Mascheroni constant
113  template<typename _Tp>
114  inline constexpr _Tp egamma_v
115  = _Enable_if_floating<_Tp>(0.577215664901532860606512090082402431L);
116 
117  /// The golden ratio, (1+sqrt(5))/2
118  template<typename _Tp>
119  inline constexpr _Tp phi_v
120  = _Enable_if_floating<_Tp>(1.618033988749894848204586834365638118L);
121 
122  inline constexpr double e = e_v<double>;
123  inline constexpr double log2e = log2e_v<double>;
124  inline constexpr double log10e = log10e_v<double>;
125  inline constexpr double pi = pi_v<double>;
126  inline constexpr double inv_pi = inv_pi_v<double>;
127  inline constexpr double inv_sqrtpi = inv_sqrtpi_v<double>;
128  inline constexpr double ln2 = ln2_v<double>;
129  inline constexpr double ln10 = ln10_v<double>;
130  inline constexpr double sqrt2 = sqrt2_v<double>;
131  inline constexpr double sqrt3 = sqrt3_v<double>;
132  inline constexpr double inv_sqrt3 = inv_sqrt3_v<double>;
133  inline constexpr double egamma = egamma_v<double>;
134  inline constexpr double phi = phi_v<double>;
135 
136 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
137  template<>
138  inline constexpr __float128 e_v<__float128>
139  = 2.718281828459045235360287471352662498Q;
140 
141  /// log_2 e
142  template<>
143  inline constexpr __float128 log2e_v<__float128>
144  = 1.442695040888963407359924681001892137Q;
145 
146  /// log_10 e
147  template<>
148  inline constexpr __float128 log10e_v<__float128>
149  = 0.434294481903251827651128918916605082Q;
150 
151  /// pi
152  template<>
153  inline constexpr __float128 pi_v<__float128>
154  = 3.141592653589793238462643383279502884Q;
155 
156  /// 1/pi
157  template<>
158  inline constexpr __float128 inv_pi_v<__float128>
159  = 0.318309886183790671537767526745028724Q;
160 
161  /// 1/sqrt(pi)
162  template<>
163  inline constexpr __float128 inv_sqrtpi_v<__float128>
164  = 0.564189583547756286948079451560772586Q;
165 
166  /// log_e 2
167  template<>
168  inline constexpr __float128 ln2_v<__float128>
169  = 0.693147180559945309417232121458176568Q;
170 
171  /// log_e 10
172  template<>
173  inline constexpr __float128 ln10_v<__float128>
174  = 2.302585092994045684017991454684364208Q;
175 
176  /// sqrt(2)
177  template<>
178  inline constexpr __float128 sqrt2_v<__float128>
179  = 1.414213562373095048801688724209698079Q;
180 
181  /// sqrt(3)
182  template<>
183  inline constexpr __float128 sqrt3_v<__float128>
184  = 1.732050807568877293527446341505872367Q;
185 
186  /// 1/sqrt(3)
187  template<>
188  inline constexpr __float128 inv_sqrt3_v<__float128>
189  = 0.577350269189625764509148780501957456Q;
190 
191  /// The Euler-Mascheroni constant
192  template<>
193  inline constexpr __float128 egamma_v<__float128>
194  = 0.577215664901532860606512090082402431Q;
195 
196  /// The golden ratio, (1+sqrt(5))/2
197  template<>
198  inline constexpr __float128 phi_v<__float128>
199  = 1.618033988749894848204586834365638118Q;
200 #endif // USE_FLOAT128
201 
202 } // namespace numbers
203 /// @}
204 _GLIBCXX_END_NAMESPACE_VERSION
205 } // namespace std
206 
207 #endif // C++20
208 #endif // _GLIBCXX_NUMBERS
ISO C++ entities toplevel namespace is std.