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// Special functions -*- C++ -*- |
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// Copyright (C) 2006-2021 Free Software Foundation, Inc. |
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// |
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// This file is part of the GNU ISO C++ Library. This library is free |
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// software; you can redistribute it and/or modify it under the |
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// terms of the GNU General Public License as published by the |
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// Free Software Foundation; either version 3, or (at your option) |
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// any later version. |
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// This library is distributed in the hope that it will be useful, |
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// but WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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// GNU General Public License for more details. |
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// Under Section 7 of GPL version 3, you are granted additional |
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// permissions described in the GCC Runtime Library Exception, version |
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// 3.1, as published by the Free Software Foundation. |
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// You should have received a copy of the GNU General Public License and |
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// a copy of the GCC Runtime Library Exception along with this program; |
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
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// <http://www.gnu.org/licenses/>. |
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/** @file tr1/special_function_util.h |
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* This is an internal header file, included by other library headers. |
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* Do not attempt to use it directly. @headername{tr1/cmath} |
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*/ |
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// |
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// ISO C++ 14882 TR1: 5.2 Special functions |
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// |
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// Written by Edward Smith-Rowland based on numerous mathematics books. |
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#ifndef _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H |
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#define _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H 1 |
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namespace std _GLIBCXX_VISIBILITY(default) |
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{ |
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_GLIBCXX_BEGIN_NAMESPACE_VERSION |
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#if _GLIBCXX_USE_STD_SPEC_FUNCS |
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#elif defined(_GLIBCXX_TR1_CMATH) |
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namespace tr1 |
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{ |
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#else |
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# error do not include this header directly, use <cmath> or <tr1/cmath> |
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#endif |
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namespace __detail |
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{ |
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/// A class to encapsulate type dependent floating point |
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/// constants. Not everything will be able to be expressed as |
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/// type logic. |
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template<typename _Tp> |
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struct __floating_point_constant |
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{ |
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static const _Tp __value; |
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}; |
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/// A structure for numeric constants. |
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template<typename _Tp> |
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struct __numeric_constants |
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{ |
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/// Constant @f$ \pi @f$. |
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static _Tp __pi() throw() |
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{ return static_cast<_Tp>(3.1415926535897932384626433832795029L); } |
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/// Constant @f$ \pi / 2 @f$. |
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static _Tp __pi_2() throw() |
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{ return static_cast<_Tp>(1.5707963267948966192313216916397514L); } |
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/// Constant @f$ \pi / 3 @f$. |
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static _Tp __pi_3() throw() |
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{ return static_cast<_Tp>(1.0471975511965977461542144610931676L); } |
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/// Constant @f$ \pi / 4 @f$. |
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static _Tp __pi_4() throw() |
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{ return static_cast<_Tp>(0.7853981633974483096156608458198757L); } |
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/// Constant @f$ 1 / \pi @f$. |
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static _Tp __1_pi() throw() |
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{ return static_cast<_Tp>(0.3183098861837906715377675267450287L); } |
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/// Constant @f$ 2 / \sqrt(\pi) @f$. |
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static _Tp __2_sqrtpi() throw() |
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{ return static_cast<_Tp>(1.1283791670955125738961589031215452L); } |
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/// Constant @f$ \sqrt(2) @f$. |
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static _Tp __sqrt2() throw() |
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{ return static_cast<_Tp>(1.4142135623730950488016887242096981L); } |
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/// Constant @f$ \sqrt(3) @f$. |
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static _Tp __sqrt3() throw() |
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{ return static_cast<_Tp>(1.7320508075688772935274463415058723L); } |
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/// Constant @f$ \sqrt(\pi/2) @f$. |
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static _Tp __sqrtpio2() throw() |
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{ return static_cast<_Tp>(1.2533141373155002512078826424055226L); } |
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/// Constant @f$ 1 / sqrt(2) @f$. |
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static _Tp __sqrt1_2() throw() |
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{ return static_cast<_Tp>(0.7071067811865475244008443621048490L); } |
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/// Constant @f$ \log(\pi) @f$. |
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static _Tp __lnpi() throw() |
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{ return static_cast<_Tp>(1.1447298858494001741434273513530587L); } |
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/// Constant Euler's constant @f$ \gamma_E @f$. |
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static _Tp __gamma_e() throw() |
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{ return static_cast<_Tp>(0.5772156649015328606065120900824024L); } |
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/// Constant Euler-Mascheroni @f$ e @f$ |
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static _Tp __euler() throw() |
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{ return static_cast<_Tp>(2.7182818284590452353602874713526625L); } |
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}; |
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#if _GLIBCXX_USE_C99_MATH && !_GLIBCXX_USE_C99_FP_MACROS_DYNAMIC |
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/// This is a wrapper for the isnan function. Otherwise, for NaN, |
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/// all comparisons result in false. If/when we build a std::isnan |
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/// out of intrinsics, this will disappear completely in favor of |
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/// std::isnan. |
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template<typename _Tp> |
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inline bool __isnan(_Tp __x) |
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{ return std::isnan(__x); } |
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#else |
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template<typename _Tp> |
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inline bool __isnan(const _Tp __x) |
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{ return __builtin_isnan(__x); } |
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template<> |
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inline bool __isnan<float>(float __x) |
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{ return __builtin_isnanf(__x); } |
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template<> |
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inline bool __isnan<long double>(long double __x) |
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{ return __builtin_isnanl(__x); } |
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#endif |
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} // namespace __detail |
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#if ! _GLIBCXX_USE_STD_SPEC_FUNCS && defined(_GLIBCXX_TR1_CMATH) |
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} // namespace tr1 |
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#endif |
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_GLIBCXX_END_NAMESPACE_VERSION |
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} |
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#endif // _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H |
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