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      1 // Numeric extensions -*- C++ -*-
      2 
      3 // Copyright (C) 2002, 2004, 2005, 2009 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 #pragma GCC system_header
     60 
     61 #include <bits/concept_check.h>
     62 #include <numeric>
     63 
     64 #include <ext/functional> // For identity_element
     65 
     66 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
     67 
     68   // Returns __x ** __n, where __n >= 0.  _Note that "multiplication"
     69   // is required to be associative, but not necessarily commutative.
     70   template<typename _Tp, typename _Integer, typename _MonoidOperation>
     71     _Tp
     72     __power(_Tp __x, _Integer __n, _MonoidOperation __monoid_op)
     73     {
     74       if (__n == 0)
     75 	return identity_element(__monoid_op);
     76       else
     77 	{
     78 	  while ((__n & 1) == 0)
     79 	    {
     80 	      __n >>= 1;
     81 	      __x = __monoid_op(__x, __x);
     82 	    }
     83 
     84 	  _Tp __result = __x;
     85 	  __n >>= 1;
     86 	  while (__n != 0)
     87 	    {
     88 	      __x = __monoid_op(__x, __x);
     89 	      if ((__n & 1) != 0)
     90 		__result = __monoid_op(__result, __x);
     91 	      __n >>= 1;
     92 	    }
     93 	  return __result;
     94 	}
     95     }
     96 
     97   template<typename _Tp, typename _Integer>
     98     inline _Tp
     99     __power(_Tp __x, _Integer __n)
    100     { return __power(__x, __n, std::multiplies<_Tp>()); }
    101 
    102   /**
    103    *  This is an SGI extension.
    104    *  @ingroup SGIextensions
    105    *  @doctodo
    106   */
    107   // Alias for the internal name __power.  Note that power is an extension,
    108   // not part of the C++ standard.
    109   template<typename _Tp, typename _Integer, typename _MonoidOperation>
    110     inline _Tp
    111     power(_Tp __x, _Integer __n, _MonoidOperation __monoid_op)
    112     { return __power(__x, __n, __monoid_op); }
    113 
    114   /**
    115    *  This is an SGI extension.
    116    *  @ingroup SGIextensions
    117    *  @doctodo
    118   */
    119   template<typename _Tp, typename _Integer>
    120     inline _Tp
    121     power(_Tp __x, _Integer __n)
    122     { return __power(__x, __n); }
    123 
    124   /**
    125    *  This is an SGI extension.
    126    *  @ingroup SGIextensions
    127    *  @doctodo
    128   */
    129   // iota is not part of the C++ standard.  It is an extension.
    130   template<typename _ForwardIter, typename _Tp>
    131     void
    132     iota(_ForwardIter __first, _ForwardIter __last, _Tp __value)
    133     {
    134       // concept requirements
    135       __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<_ForwardIter>)
    136       __glibcxx_function_requires(_ConvertibleConcept<_Tp,
    137 	    typename std::iterator_traits<_ForwardIter>::value_type>)
    138 
    139       while (__first != __last)
    140 	*__first++ = __value++;
    141     }
    142 
    143 _GLIBCXX_END_NAMESPACE
    144 
    145 #endif
    146 
    147