1// <numeric> -*- C++ -*-
2
3// Copyright (C) 2001-2018 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) 1996,1997
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 > 201402L
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_GLIBCXX_END_NAMESPACE_VERSION
160} // namespace std
161
162#endif // C++14
163
164
165#endif /* _GLIBCXX_NUMERIC */
166