libstdc++-v3/include/experimental/numeric

   1 // <experimental/numeric> -*- C++ -*-
   2
   3 // Copyright (C) 2015 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 /** @file experimental/numeric
  26  *  This is a TS C++ Library header.
  27  */
  28
  29 //
  30 // N4336 Working Draft, C++ Extensions for Library Fundamentals, Version 2
  31 //
  32
  33 #ifndef _GLIBCXX_EXPERIMENTAL_NUMERIC
  34 #define _GLIBCXX_EXPERIMENTAL_NUMERIC 1
  35
  36 #pragma GCC system_header
  37
  38 #if __cplusplus <= 201103L
  39 # include <bits/c++14_warning.h>
  40 #else
  41
  42 #include <experimental/type_traits>
  43 #include <cmath>
  44
  45 namespace std _GLIBCXX_VISIBILITY(default)
  46 {
  47 namespace experimental
  48 {
  49 inline namespace fundamentals_v2
  50 {
  51 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  52
  53 #define __cpp_lib_experimental_gcd_lcm 201411
  54
  55   // Greatest common divisor
  56   template<typename _Mn, typename _Nn>
  57     constexpr common_type_t<_Mn, _Nn>
  58     gcd(_Mn __m, _Nn __n)
  59     {
  60       static_assert(is_integral<_Mn>::value, "arguments to gcd are integers");
  61       static_assert(is_integral<_Nn>::value, "arguments to gcd are integers");
  62
  63       return __m == 0 ? std::abs(__n)
  64         : __n == 0 ? std::abs(__m)
  65         : fundamentals_v2::gcd(__n, __m % __n);
  66     }
  67
  68   // Least common multiple
  69   template<typename _Mn, typename _Nn>
  70     constexpr common_type_t<_Mn, _Nn>
  71     lcm(_Mn __m, _Nn __n)
  72     {
  73       static_assert(is_integral<_Mn>::value, "arguments to lcm are integers");
  74       static_assert(is_integral<_Nn>::value, "arguments to lcm are integers");
  75
  76       return (__m != 0 && __n != 0)
  77         ? (std::abs(__m) / fundamentals_v2::gcd(__m, __n)) * std::abs(__n)
  78         : 0;
  79     }
  80
  81 _GLIBCXX_END_NAMESPACE_VERSION
  82 } // namespace fundamentals_v2
  83 } // namespace experimental
  84 } // namespace std
  85
  86 #endif // __cplusplus <= 201103L
  87
  88 #endif // _GLIBCXX_EXPERIMENTAL_NUMERIC