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The C and C++ Include Header Files

cat -n /usr/include/c++/15/ext/numeric

     1	// Numeric extensions -*- C++ -*-
     2	
     3	// Copyright (C) 2002-2025 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	/*
    26	 *
    27	 * Copyright (c) 1994
    28	 * Hewlett-Packard Company
    29	 *
    30	 * Permission to use, copy, modify, distribute and sell this software
    31	 * and its documentation for any purpose is hereby granted without fee,
    32	 * provided that the above copyright notice appear in all copies and
    33	 * that both that copyright notice and this permission notice appear
    34	 * in supporting documentation.  Hewlett-Packard Company makes no
    35	 * representations about the suitability of this software for any
    36	 * purpose.  It is provided "as is" without express or implied warranty.
    37	 *
    38	 *
    39	 * Copyright (c) 1996
    40	 * Silicon Graphics Computer Systems, Inc.
    41	 *
    42	 * Permission to use, copy, modify, distribute and sell this software
    43	 * and its documentation for any purpose is hereby granted without fee,
    44	 * provided that the above copyright notice appear in all copies and
    45	 * that both that copyright notice and this permission notice appear
    46	 * in supporting documentation.  Silicon Graphics makes no
    47	 * representations about the suitability of this software for any
    48	 * purpose.  It is provided "as is" without express or implied warranty.
    49	 */
    50	
    51	/** @file ext/numeric
    52	 *  This file is a GNU extension to the Standard C++ Library (possibly
    53	 *  containing extensions from the HP/SGI STL subset). 
    54	 */
    55	
    56	#ifndef _EXT_NUMERIC
    57	#define _EXT_NUMERIC 1
    58	
    59	#ifdef _GLIBCXX_SYSHDR
    60	#pragma GCC system_header
    61	#endif
    62	
    63	#include <bits/requires_hosted.h> // GNU extensions are currently omitted
    64	
    65	#include <bits/concept_check.h>
    66	#include <numeric>
    67	
    68	#include <ext/functional> // For identity_element
    69	
    70	namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
    71	{
    72	_GLIBCXX_BEGIN_NAMESPACE_VERSION
    73	
    74	  // Returns __x ** __n, where __n >= 0.  _Note that "multiplication"
    75	  // is required to be associative, but not necessarily commutative.
    76	  template<typename _Tp, typename _Integer, typename _MonoidOperation>
    77	    _Tp
    78	    __power(_Tp __x, _Integer __n, _MonoidOperation __monoid_op)
    79	    {
    80	      if (__n == 0)
    81		return identity_element(__monoid_op);
    82	      else
    83		{
    84		  while ((__n & 1) == 0)
    85		    {
    86		      __n >>= 1;
    87		      __x = __monoid_op(__x, __x);
    88		    }
    89	
    90		  _Tp __result = __x;
    91		  __n >>= 1;
    92		  while (__n != 0)
    93		    {
    94		      __x = __monoid_op(__x, __x);
    95		      if ((__n & 1) != 0)
    96			__result = __monoid_op(__result, __x);
    97		      __n >>= 1;
    98		    }
    99		  return __result;
   100		}
   101	    }
   102	
   103	  template<typename _Tp, typename _Integer>
   104	    inline _Tp
   105	    __power(_Tp __x, _Integer __n)
   106	    { return __power(__x, __n, std::multiplies<_Tp>()); }
   107	
   108	  /**
   109	   *  This is an SGI extension.
   110	   *  @ingroup SGIextensions
   111	   *  @doctodo
   112	  */
   113	  // Alias for the internal name __power.  Note that power is an extension,
   114	  // not part of the C++ standard.
   115	  template<typename _Tp, typename _Integer, typename _MonoidOperation>
   116	    inline _Tp
   117	    power(_Tp __x, _Integer __n, _MonoidOperation __monoid_op)
   118	    { return __power(__x, __n, __monoid_op); }
   119	
   120	  /**
   121	   *  This is an SGI extension.
   122	   *  @ingroup SGIextensions
   123	   *  @doctodo
   124	  */
   125	  template<typename _Tp, typename _Integer>
   126	    inline _Tp
   127	    power(_Tp __x, _Integer __n)
   128	    { return __power(__x, __n); }
   129	
   130	#if __cplusplus >= 201103L
   131	  using std::iota;
   132	#else
   133	  /**
   134	   *  This is an SGI extension.
   135	   *  @ingroup SGIextensions
   136	   *  @doctodo
   137	  */
   138	  // iota is not part of the standard until C++11.  It is an extension.
   139	  template<typename _ForwardIter, typename _Tp>
   140	    void
   141	    iota(_ForwardIter __first, _ForwardIter __last, _Tp __value)
   142	    {
   143	      // concept requirements
   144	      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<_ForwardIter>)
   145	      __glibcxx_function_requires(_ConvertibleConcept<_Tp,
   146		    typename std::iterator_traits<_ForwardIter>::value_type>)
   147	
   148	      while (__first != __last)
   149		*__first++ = __value++;
   150	    }
   151	#endif  // C++11
   152	
   153	_GLIBCXX_END_NAMESPACE_VERSION
   154	} // namespace
   155	
   156	#endif