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