1// <numeric> -*- C++ -*-
2
3// Copyright (C) 2001-2019 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{
82_GLIBCXX_BEGIN_NAMESPACE_VERSION
83
84namespace __detail
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} // namespace __detail
121
122#if __cplusplus >= 201703L
123
124#define __cpp_lib_gcd_lcm 201606
125// These were used in drafts of SD-6:
126#define __cpp_lib_gcd 201606
127#define __cpp_lib_lcm 201606
128
129 /// Greatest common divisor
130 template<typename _Mn, typename _Nn>
131 constexpr common_type_t<_Mn, _Nn>
132 gcd(_Mn __m, _Nn __n)
133 {
134 static_assert(is_integral_v<_Mn>, "gcd arguments are integers");
135 static_assert(is_integral_v<_Nn>, "gcd arguments are integers");
136 static_assert(!is_same_v<remove_cv_t<_Mn>, bool>,
137 "gcd arguments are not bools");
138 static_assert(!is_same_v<remove_cv_t<_Nn>, bool>,
139 "gcd arguments are not bools");
140 return __detail::__gcd(__m, __n);
141 }
142
143 /// Least common multiple
144 template<typename _Mn, typename _Nn>
145 constexpr common_type_t<_Mn, _Nn>
146 lcm(_Mn __m, _Nn __n)
147 {
148 static_assert(is_integral_v<_Mn>, "lcm arguments are integers");
149 static_assert(is_integral_v<_Nn>, "lcm arguments are integers");
150 static_assert(!is_same_v<remove_cv_t<_Mn>, bool>,
151 "lcm arguments are not bools");
152 static_assert(!is_same_v<remove_cv_t<_Nn>, bool>,
153 "lcm arguments are not bools");
154 return __detail::__lcm(__m, __n);
155 }
156
157#endif // C++17
158
159#if __cplusplus > 201703L
160 // midpoint
161# define __cpp_lib_interpolate 201902L
162
163template<typename _Tp>
164 constexpr
165 enable_if_t<__and_v<is_arithmetic<_Tp>, is_same<remove_cv_t<_Tp>, _Tp>,
166 __not_<is_same<_Tp, bool>>>,
167 _Tp>
168 midpoint(_Tp __a, _Tp __b) noexcept
169 {
170 if constexpr (is_integral_v<_Tp>)
171 {
172 using _Up = make_unsigned_t<_Tp>;
173
174 int __k = 1;
175 _Up __m = __a;
176 _Up __M = __b;
177 if (__a > __b)
178 {
179 __k = -1;
180 __m = __b;
181 __M = __a;
182 }
183 return __a + __k * _Tp(_Up(__M - __m) / 2);
184 }
185 else
186 {
187 return __builtin_isnormal(__a) && __builtin_isnormal(__b)
188 ? __a / 2 + __b / 2
189 : (__a + __b) / 2;
190 }
191 }
192
193 template<typename _Tp>
194 constexpr
195 enable_if_t<__and_v<is_object<_Tp>, bool_constant<sizeof(_Tp) != 0>>, _Tp*>
196 midpoint(_Tp* __a, _Tp* __b) noexcept
197 {
198 return __a > __b ? __b + (__a - __b) / 2 : __a + (__b - __a) / 2;
199 }
200#endif // C++20
201
202_GLIBCXX_END_NAMESPACE_VERSION
203} // namespace std
204
205#endif // C++14
206
207#if __cplusplus > 201402L
208// Parallel STL algorithms
209# if __PSTL_EXECUTION_POLICIES_DEFINED
210// If <execution> has already been included, pull in implementations
211# include <pstl/glue_numeric_impl.h>
212# else
213// Otherwise just pull in forward declarations
214# include <pstl/glue_numeric_defs.h>
215# define __PSTL_NUMERIC_FORWARD_DECLARED 1
216# endif
217
218// Feature test macro for parallel algorithms
219# define __cpp_lib_parallel_algorithm 201703L
220#endif // C++17
221
222#endif /* _GLIBCXX_NUMERIC */
223