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The C and C++ Include Header Files

/usr/include/c++/13/tr1/special_function_util.h


$ cat -n /usr/include/c++/13/tr1/special_function_util.h

     1	// Special functions -*- C++ -*-
     2	
     3	// Copyright (C) 2006-2023 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