Retro68/gcc/libstdc++-v3/include/experimental/numeric
2017-04-10 13:32:00 +02:00

103 lines
3.0 KiB
C++

// <experimental/numeric> -*- C++ -*-
// Copyright (C) 2015-2016 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 <= 201103L
# include <bits/c++14_warning.h>
#else
#include <numeric>
#include <experimental/type_traits>
namespace std _GLIBCXX_VISIBILITY(default)
{
namespace experimental
{
inline namespace fundamentals_v2
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
#define __cpp_lib_experimental_gcd_lcm 201411
// std::abs is not constexpr and doesn't support unsigned integers.
template<typename _Tp>
constexpr
enable_if_t<__and_<is_integral<_Tp>, is_signed<_Tp>>::value, _Tp>
__abs(_Tp __val)
{ return __val < 0 ? -__val : __val; }
template<typename _Tp>
constexpr
enable_if_t<__and_<is_integral<_Tp>, is_unsigned<_Tp>>::value, _Tp>
__abs(_Tp __val)
{ return __val; }
// Greatest common divisor
template<typename _Mn, typename _Nn>
constexpr common_type_t<_Mn, _Nn>
gcd(_Mn __m, _Nn __n)
{
static_assert(is_integral<_Mn>::value, "arguments to gcd are integers");
static_assert(is_integral<_Nn>::value, "arguments to gcd are integers");
return __m == 0 ? fundamentals_v2::__abs(__n)
: __n == 0 ? fundamentals_v2::__abs(__m)
: fundamentals_v2::gcd(__n, __m % __n);
}
// Least common multiple
template<typename _Mn, typename _Nn>
constexpr common_type_t<_Mn, _Nn>
lcm(_Mn __m, _Nn __n)
{
static_assert(is_integral<_Mn>::value, "arguments to lcm are integers");
static_assert(is_integral<_Nn>::value, "arguments to lcm are integers");
return (__m != 0 && __n != 0)
? (fundamentals_v2::__abs(__m) / fundamentals_v2::gcd(__m, __n))
* fundamentals_v2::__abs(__n)
: 0;
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace fundamentals_v2
} // namespace experimental
} // namespace std
#endif // __cplusplus <= 201103L
#endif // _GLIBCXX_EXPERIMENTAL_NUMERIC