libstdc++
numeric
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00001 // <numeric> -*- C++ -*-
00002 
00003 // Copyright (C) 2001-2017 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 3, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /*
00026  *
00027  * Copyright (c) 1994
00028  * Hewlett-Packard Company
00029  *
00030  * Permission to use, copy, modify, distribute and sell this software
00031  * and its documentation for any purpose is hereby granted without fee,
00032  * provided that the above copyright notice appear in all copies and
00033  * that both that copyright notice and this permission notice appear
00034  * in supporting documentation.  Hewlett-Packard Company makes no
00035  * representations about the suitability of this software for any
00036  * purpose.  It is provided "as is" without express or implied warranty.
00037  *
00038  *
00039  * Copyright (c) 1996,1997
00040  * Silicon Graphics Computer Systems, Inc.
00041  *
00042  * Permission to use, copy, modify, distribute and sell this software
00043  * and its documentation for any purpose is hereby granted without fee,
00044  * provided that the above copyright notice appear in all copies and
00045  * that both that copyright notice and this permission notice appear
00046  * in supporting documentation.  Silicon Graphics makes no
00047  * representations about the suitability of this software for any
00048  * purpose.  It is provided "as is" without express or implied warranty.
00049  */
00050 
00051 /** @file include/numeric
00052  *  This is a Standard C++ Library header.
00053  */
00054 
00055 #ifndef _GLIBCXX_NUMERIC
00056 #define _GLIBCXX_NUMERIC 1
00057 
00058 #pragma GCC system_header
00059 
00060 #include <bits/c++config.h>
00061 #include <bits/stl_iterator_base_types.h>
00062 #include <bits/stl_numeric.h>
00063 
00064 #ifdef _GLIBCXX_PARALLEL
00065 # include <parallel/numeric>
00066 #endif
00067 
00068 /**
00069  * @defgroup numerics Numerics
00070  *
00071  * Components for performing numeric operations. Includes support for
00072  * for complex number types, random number generation, numeric
00073  * (n-at-a-time) arrays, generalized numeric algorithms, and special
00074  * math functions.
00075  */
00076 
00077 #if __cplusplus >= 201402L
00078 #include <type_traits>
00079 
00080 namespace std _GLIBCXX_VISIBILITY(default)
00081 {
00082 namespace __detail
00083 {
00084 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00085 
00086   // std::abs is not constexpr and doesn't support unsigned integers.
00087   template<typename _Tp>
00088     constexpr
00089     enable_if_t<__and_<is_integral<_Tp>, is_signed<_Tp>>::value, _Tp>
00090     __abs_integral(_Tp __val)
00091     { return __val < 0 ? -__val : __val; }
00092 
00093   template<typename _Tp>
00094     constexpr
00095     enable_if_t<__and_<is_integral<_Tp>, is_unsigned<_Tp>>::value, _Tp>
00096     __abs_integral(_Tp __val)
00097     { return __val; }
00098 
00099   void __abs_integral(bool) = delete;
00100 
00101   template<typename _Mn, typename _Nn>
00102     constexpr common_type_t<_Mn, _Nn>
00103     __gcd(_Mn __m, _Nn __n)
00104     {
00105       return __m == 0 ? __detail::__abs_integral(__n)
00106         : __n == 0 ? __detail::__abs_integral(__m)
00107         : __detail::__gcd(__n, __m % __n);
00108     }
00109 
00110   /// Least common multiple
00111   template<typename _Mn, typename _Nn>
00112     constexpr common_type_t<_Mn, _Nn>
00113     __lcm(_Mn __m, _Nn __n)
00114     {
00115       return (__m != 0 && __n != 0)
00116         ? (__detail::__abs_integral(__m) / __detail::__gcd(__m, __n))
00117           * __detail::__abs_integral(__n)
00118         : 0;
00119     }
00120 
00121 _GLIBCXX_END_NAMESPACE_VERSION
00122 }
00123 
00124 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00125 
00126 #if __cplusplus > 201402L
00127 
00128 #define __cpp_lib_gcd 201606
00129   /// Greatest common divisor
00130   template<typename _Mn, typename _Nn>
00131     constexpr common_type_t<_Mn, _Nn>
00132     gcd(_Mn __m, _Nn __n)
00133     {
00134       static_assert(is_integral<_Mn>::value, "gcd arguments are integers");
00135       static_assert(is_integral<_Nn>::value, "gcd arguments are integers");
00136       static_assert(!is_same<_Mn, bool>::value, "gcd arguments are not bools");
00137       static_assert(!is_same<_Nn, bool>::value, "gcd arguments are not bools");
00138       return __detail::__gcd(__m, __n);
00139     }
00140 
00141 #define __cpp_lib_lcm 201606
00142   /// Least common multiple
00143   template<typename _Mn, typename _Nn>
00144     constexpr common_type_t<_Mn, _Nn>
00145     lcm(_Mn __m, _Nn __n)
00146     {
00147       static_assert(is_integral<_Mn>::value, "lcm arguments are integers");
00148       static_assert(is_integral<_Nn>::value, "lcm arguments are integers");
00149       static_assert(!is_same<_Mn, bool>::value, "lcm arguments are not bools");
00150       static_assert(!is_same<_Nn, bool>::value, "lcm arguments are not bools");
00151       return __detail::__lcm(__m, __n);
00152     }
00153 
00154 #endif // C++17
00155 
00156 _GLIBCXX_END_NAMESPACE_VERSION
00157 } // namespace std
00158 
00159 #endif // C++14
00160 
00161 
00162 #endif /* _GLIBCXX_NUMERIC */