1// <numeric> -*- C++ -*-
2
3// Copyright (C) 2001-2017 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) 1996,1997
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 include/numeric
52 * This is a Standard C++ Library header.
53 */
54
55#ifndef _GLIBCXX_NUMERIC
56#define _GLIBCXX_NUMERIC 1
57
58#pragma GCC system_header
59
60#include <bits/c++config.h>
61#include <bits/stl_iterator_base_types.h>
62#include <bits/stl_numeric.h>
63
64#ifdef _GLIBCXX_PARALLEL
65# include <parallel/numeric>
66#endif
67
68/**
69 * @defgroup numerics Numerics
70 *
71 * Components for performing numeric operations. Includes support for
72 * for complex number types, random number generation, numeric
73 * (n-at-a-time) arrays, generalized numeric algorithms, and special
74 * math functions.
75 */
76
77#if __cplusplus >= 201402L
78#include <type_traits>
79
80namespace std _GLIBCXX_VISIBILITY(default)
81{
82namespace __detail
83{
84_GLIBCXX_BEGIN_NAMESPACE_VERSION
85
86 // std::abs is not constexpr and doesn't support unsigned integers.
87 template<typename _Tp>
88 constexpr
89 enable_if_t<__and_<is_integral<_Tp>, is_signed<_Tp>>::value, _Tp>
90 __abs_integral(_Tp __val)
91 { return __val < 0 ? -__val : __val; }
92
93 template<typename _Tp>
94 constexpr
95 enable_if_t<__and_<is_integral<_Tp>, is_unsigned<_Tp>>::value, _Tp>
96 __abs_integral(_Tp __val)
97 { return __val; }
98
99 void __abs_integral(bool) = delete;
100
101 template<typename _Mn, typename _Nn>
102 constexpr common_type_t<_Mn, _Nn>
103 __gcd(_Mn __m, _Nn __n)
104 {
105 return __m == 0 ? __detail::__abs_integral(__n)
106 : __n == 0 ? __detail::__abs_integral(__m)
107 : __detail::__gcd(__n, __m % __n);
108 }
109
110 /// Least common multiple
111 template<typename _Mn, typename _Nn>
112 constexpr common_type_t<_Mn, _Nn>
113 __lcm(_Mn __m, _Nn __n)
114 {
115 return (__m != 0 && __n != 0)
116 ? (__detail::__abs_integral(__m) / __detail::__gcd(__m, __n))
117 * __detail::__abs_integral(__n)
118 : 0;
119 }
120
121_GLIBCXX_END_NAMESPACE_VERSION
122}
123
124_GLIBCXX_BEGIN_NAMESPACE_VERSION
125
126#if __cplusplus > 201402L
127
128#define __cpp_lib_gcd_lcm 201606
129// These were used in drafts of SD-6:
130#define __cpp_lib_gcd 201606
131#define __cpp_lib_lcm 201606
132
133 /// Greatest common divisor
134 template<typename _Mn, typename _Nn>
135 constexpr common_type_t<_Mn, _Nn>
136 gcd(_Mn __m, _Nn __n)
137 {
138 static_assert(is_integral<_Mn>::value, "gcd arguments are integers");
139 static_assert(is_integral<_Nn>::value, "gcd arguments are integers");
140 static_assert(!is_same<_Mn, bool>::value, "gcd arguments are not bools");
141 static_assert(!is_same<_Nn, bool>::value, "gcd arguments are not bools");
142 return __detail::__gcd(__m, __n);
143 }
144
145 /// Least common multiple
146 template<typename _Mn, typename _Nn>
147 constexpr common_type_t<_Mn, _Nn>
148 lcm(_Mn __m, _Nn __n)
149 {
150 static_assert(is_integral<_Mn>::value, "lcm arguments are integers");
151 static_assert(is_integral<_Nn>::value, "lcm arguments are integers");
152 static_assert(!is_same<_Mn, bool>::value, "lcm arguments are not bools");
153 static_assert(!is_same<_Nn, bool>::value, "lcm arguments are not bools");
154 return __detail::__lcm(__m, __n);
155 }
156
157#endif // C++17
158
159_GLIBCXX_END_NAMESPACE_VERSION
160} // namespace std
161
162#endif // C++14
163
164
165#endif /* _GLIBCXX_NUMERIC */
166