1// Special functions -*- C++ -*- 
2 
3// Copyright (C) 2006-2019 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 
39namespace std _GLIBCXX_VISIBILITY(default) 
40{ 
41_GLIBCXX_BEGIN_NAMESPACE_VERSION 
42 
43#if _GLIBCXX_USE_STD_SPEC_FUNCS 
44#elif defined(_GLIBCXX_TR1_CMATH) 
45namespace 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