Filename: //usr/include/c++/8/experimental/numeric

// <experimental/numeric> -*- C++ -*-

// Copyright (C) 2015-2018 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file experimental/numeric
 *  This is a TS C++ Library header.
 */

//
// N4336 Working Draft, C++ Extensions for Library Fundamentals, Version 2
//

#ifndef _GLIBCXX_EXPERIMENTAL_NUMERIC
#define _GLIBCXX_EXPERIMENTAL_NUMERIC 1

#pragma GCC system_header

#if __cplusplus >= 201402L

#include <numeric>
#include <experimental/type_traits>

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

namespace experimental
{
inline namespace fundamentals_v2
{
#define __cpp_lib_experimental_gcd_lcm 201411

  /// Greatest common divisor
  template<typename _Mn, typename _Nn>
    constexpr common_type_t<_Mn, _Nn>
    gcd(_Mn __m, _Nn __n) noexcept
    {
      static_assert(is_integral_v<_Mn>,
	  "std::experimental::gcd arguments must be integers");
      static_assert(is_integral_v<_Nn>,
	  "std::experimental::gcd arguments must be integers");
      static_assert(_Mn(2) != _Mn(1),
	  "std::experimental::gcd arguments must not be bool");
      static_assert(_Nn(2) != _Nn(1),
	  "std::experimental::gcd arguments must not be bool");
      using _Up = make_unsigned_t<common_type_t<_Mn, _Nn>>;
      return std::__detail::__gcd(std::__detail::__absu<_Up>(__m),
				  std::__detail::__absu<_Up>(__n));
    }

  /// Least common multiple
  template<typename _Mn, typename _Nn>
    constexpr common_type_t<_Mn, _Nn>
    lcm(_Mn __m, _Nn __n)
    {
      static_assert(is_integral_v<_Mn>,
	  "std::experimental::lcm arguments must be integers");
      static_assert(is_integral_v<_Nn>,
	  "std::experimental::lcm arguments must be integers");
      static_assert(_Mn(2) != _Mn(1),
	  "std::experimental::lcm arguments must not be bool");
      static_assert(_Nn(2) != _Nn(1),
	  "std::experimental::lcm arguments must not be bool");
      using _Up = make_unsigned_t<common_type_t<_Mn, _Nn>>;
      return std::__detail::__lcm(std::__detail::__absu<_Up>(__m),
				  std::__detail::__absu<_Up>(__n));
    }
} // namespace fundamentals_v2
} // namespace experimental

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std

#endif // __cplusplus <= 201103L

#endif // _GLIBCXX_EXPERIMENTAL_NUMERIC

./Ninja\.