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// Minimal replacement for numeric_limits of integers. -*- C++ -*-
// Copyright (C) 2020 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 bits/int_limits.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{limits}
*/
#ifndef _GLIBCXX_INT_LIMITS_H
#define _GLIBCXX_INT_LIMITS_H 1
#pragma GCC system_header
#if __cplusplus >= 201103L
#include <bits/c++config.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
namespace __detail
{
// This template is used for arbitrary signed and unsigned integer types
// (by headers <bit> and <charconv>) and for specific integer types
// (by <memory_resource> and <string_view>) but also for char (<charconv>).
// For simplicity's sake, all integral types except bool are supported.
// Lightweight alternative to numeric_limits<signed integer type>.
template<typename _Tp, bool = is_signed<_Tp>::value>
struct __int_limits
{
static_assert(is_integral<_Tp>::value, "unsupported specialization");
using _Up = typename make_unsigned<_Tp>::type;
static constexpr int digits = sizeof(_Tp) * __CHAR_BIT__ - 1;
static constexpr _Tp min() noexcept { return _Tp(_Up(1) << digits); }
static constexpr _Tp max() noexcept { return _Tp(_Up(~_Up(0)) >> 1); }
};
// Lightweight alternative to numeric_limits<unsigned integer type>.
template<typename _Tp>
struct __int_limits<_Tp, false>
{
static_assert(is_integral<_Tp>::value, "unsupported specialization");
static constexpr int digits = sizeof(_Tp) * __CHAR_BIT__;
static constexpr _Tp min() noexcept { return 0; }
static constexpr _Tp max() noexcept { return _Tp(-1); }
};
template<> struct __int_limits<bool>; // not defined
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif // C++11
#endif // _GLIBCXX_INT_LIMITS_H