Mercurial > hg > CbC > CbC_gcc
view libstdc++-v3/include/bits/int_limits.h @ 152:2b5abeee2509
update gcc11
author | anatofuz |
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date | Mon, 25 May 2020 07:50:57 +0900 |
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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