1// Numeric extensions -*- C++ -*-
2
3// Copyright (C) 2002-2018 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
66namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
67{
68_GLIBCXX_BEGIN_NAMESPACE_VERSION
69
70  // Returns __x ** __n, where __n >= 0.  _Note that "multiplication"
71  // is required to be associative, but not necessarily commutative.
72  template<typename _Tp, typename _Integer, typename _MonoidOperation>
73    _Tp
74    __power(_Tp __x, _Integer __n, _MonoidOperation __monoid_op)
75    {
76      if (__n == 0)
77	return identity_element(__monoid_op);
78      else
79	{
80	  while ((__n & 1) == 0)
81	    {
82	      __n >>= 1;
83	      __x = __monoid_op(__x, __x);
84	    }
85
86	  _Tp __result = __x;
87	  __n >>= 1;
88	  while (__n != 0)
89	    {
90	      __x = __monoid_op(__x, __x);
91	      if ((__n & 1) != 0)
92		__result = __monoid_op(__result, __x);
93	      __n >>= 1;
94	    }
95	  return __result;
96	}
97    }
98
99  template<typename _Tp, typename _Integer>
100    inline _Tp
101    __power(_Tp __x, _Integer __n)
102    { return __power(__x, __n, std::multiplies<_Tp>()); }
103
104  /**
105   *  This is an SGI extension.
106   *  @ingroup SGIextensions
107   *  @doctodo
108  */
109  // Alias for the internal name __power.  Note that power is an extension,
110  // not part of the C++ standard.
111  template<typename _Tp, typename _Integer, typename _MonoidOperation>
112    inline _Tp
113    power(_Tp __x, _Integer __n, _MonoidOperation __monoid_op)
114    { return __power(__x, __n, __monoid_op); }
115
116  /**
117   *  This is an SGI extension.
118   *  @ingroup SGIextensions
119   *  @doctodo
120  */
121  template<typename _Tp, typename _Integer>
122    inline _Tp
123    power(_Tp __x, _Integer __n)
124    { return __power(__x, __n); }
125
126#if __cplusplus >= 201103L
127  using std::iota;
128#else
129  /**
130   *  This is an SGI extension.
131   *  @ingroup SGIextensions
132   *  @doctodo
133  */
134  // iota is not part of the C++ standard.  It is an extension.
135  template<typename _ForwardIter, typename _Tp>
136    void
137    iota(_ForwardIter __first, _ForwardIter __last, _Tp __value)
138    {
139      // concept requirements
140      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<_ForwardIter>)
141      __glibcxx_function_requires(_ConvertibleConcept<_Tp,
142	    typename std::iterator_traits<_ForwardIter>::value_type>)
143
144      while (__first != __last)
145	*__first++ = __value++;
146    }
147#endif  // C++11
148
149_GLIBCXX_END_NAMESPACE_VERSION
150} // namespace
151
152#endif
153