| // Components for compile-time parsing of numbers -*- C++ -*- |
| |
| // Copyright (C) 2013-2014 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/parse_numbers.h |
| * This is an internal header file, included by other library headers. |
| * Do not attempt to use it directly. @headername{chrono} |
| */ |
| |
| #ifndef _PARSE_NUMBERS_H |
| #define _PARSE_NUMBERS_H 1 |
| |
| #pragma GCC system_header |
| |
| // From n3642.pdf except I added binary literals and digit separator '\''. |
| |
| #if __cplusplus > 201103L |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| namespace __parse_int { |
| |
| template<unsigned _Base, char _Dig> |
| struct _Digit; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, '0'> |
| { |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, '1'> |
| { |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{1}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, '2'> |
| { |
| static_assert(_Base > 2, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{2}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, '3'> |
| { |
| static_assert(_Base > 3, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{3}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, '4'> |
| { |
| static_assert(_Base > 4, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{4}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, '5'> |
| { |
| static_assert(_Base > 5, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{5}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, '6'> |
| { |
| static_assert(_Base > 6, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{6}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, '7'> |
| { |
| static_assert(_Base > 7, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{7}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, '8'> |
| { |
| static_assert(_Base > 8, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{8}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, '9'> |
| { |
| static_assert(_Base > 9, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{9}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'a'> |
| { |
| static_assert(_Base > 0xa, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xa}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'A'> |
| { |
| static_assert(_Base > 0xa, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xa}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'b'> |
| { |
| static_assert(_Base > 0xb, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xb}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'B'> |
| { |
| static_assert(_Base > 0xb, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xb}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'c'> |
| { |
| static_assert(_Base > 0xc, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xc}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'C'> |
| { |
| static_assert(_Base > 0xc, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xc}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'd'> |
| { |
| static_assert(_Base > 0xd, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xd}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'D'> |
| { |
| static_assert(_Base > 0xd, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xd}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'e'> |
| { |
| static_assert(_Base > 0xe, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xe}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'E'> |
| { |
| static_assert(_Base > 0xe, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xe}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'f'> |
| { |
| static_assert(_Base > 0xf, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xf}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digit<_Base, 'F'> |
| { |
| static_assert(_Base > 0xf, "invalid digit"); |
| static constexpr bool valid{true}; |
| static constexpr unsigned value{0xf}; |
| }; |
| |
| // Digit separator |
| template<unsigned _Base> |
| struct _Digit<_Base, '\''> |
| { |
| static constexpr bool valid{false}; |
| static constexpr unsigned value{0}; |
| }; |
| |
| |
| //------------------------------------------------------------------------------ |
| |
| template<unsigned _Base, char _Dig, char... _Digs> |
| struct _Digits_help |
| { |
| static constexpr unsigned |
| value{_Digit<_Base, _Dig>::valid ? |
| 1U + _Digits_help<_Base, _Digs...>::value : |
| _Digits_help<_Base, _Digs...>::value}; |
| }; |
| |
| template<unsigned _Base, char _Dig> |
| struct _Digits_help<_Base, _Dig> |
| { |
| static constexpr unsigned value{_Digit<_Base, _Dig>::valid ? 1U : 0U}; |
| }; |
| |
| template<unsigned _Base, char... _Digs> |
| struct _Digits |
| { |
| static constexpr unsigned value{_Digits_help<_Base, _Digs...>::value}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Digits<_Base> |
| { |
| static constexpr unsigned value{0U}; |
| }; |
| |
| //------------------------------------------------------------------------------ |
| |
| template<unsigned _Base, char _Dig, char... _Digs> |
| struct _Power_help |
| { |
| static constexpr unsigned |
| value{_Digit<_Base, _Dig>::valid ? |
| _Base * _Power_help<_Base, _Digs...>::value : |
| _Power_help<_Base, _Digs...>::value}; |
| }; |
| |
| template<unsigned _Base, char _Dig> |
| struct _Power_help<_Base, _Dig> |
| { |
| static constexpr unsigned value{_Digit<_Base, _Dig>::valid ? 1U : 0U}; |
| }; |
| |
| template<unsigned _Base, char... _Digs> |
| struct _Power |
| { |
| static constexpr unsigned value{_Power_help<_Base, _Digs...>::value}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Power<_Base> |
| { |
| static constexpr unsigned value{0U}; |
| }; |
| |
| //------------------------------------------------------------------------------ |
| |
| template<unsigned _Base, unsigned _Pow, char _Dig, char... _Digs> |
| struct _Number_help |
| { |
| static constexpr unsigned |
| value{_Digit<_Base, _Dig>::valid ? |
| _Pow * _Digit<_Base, _Dig>::value |
| + _Number_help<_Base, _Pow / _Base, _Digs...>::value : |
| _Number_help<_Base, _Pow, _Digs...>::value}; |
| }; |
| |
| template<unsigned _Base, unsigned _Pow, char _Dig> |
| struct _Number_help<_Base, _Pow, _Dig> |
| { |
| //static_assert(_Pow == 1U, "power should be one"); |
| static constexpr unsigned |
| value{_Digit<_Base, _Dig>::valid ? _Digit<_Base, _Dig>::value : 0U}; |
| }; |
| |
| template<unsigned _Base, char... _Digs> |
| struct _Number |
| { |
| static constexpr unsigned |
| value{_Number_help<_Base, _Power<_Base, _Digs...>::value, |
| _Digs...>::value}; |
| }; |
| |
| template<unsigned _Base> |
| struct _Number<_Base> |
| { |
| static constexpr unsigned value{0U}; |
| }; |
| |
| //------------------------------------------------------------------------------ |
| // This _Parse_int is the same 'level' as the old _Base_dispatch. |
| |
| template<char... _Digs> |
| struct _Parse_int; |
| |
| template<char... _Digs> |
| struct _Parse_int<'0', 'b', _Digs...> |
| { |
| static constexpr unsigned long long |
| value{_Number<2U, _Digs...>::value}; |
| }; |
| |
| template<char... _Digs> |
| struct _Parse_int<'0', 'B', _Digs...> |
| { |
| static constexpr unsigned long long |
| value{_Number<2U, _Digs...>::value}; |
| }; |
| |
| template<char... _Digs> |
| struct _Parse_int<'0', 'x', _Digs...> |
| { |
| static constexpr unsigned long long |
| value{_Number<16U, _Digs...>::value}; |
| }; |
| |
| template<char... _Digs> |
| struct _Parse_int<'0', 'X', _Digs...> |
| { |
| static constexpr unsigned long long |
| value{_Number<16U, _Digs...>::value}; |
| }; |
| |
| template<char... _Digs> |
| struct _Parse_int<'0', _Digs...> |
| { |
| static constexpr unsigned long long |
| value{_Number<8U, _Digs...>::value}; |
| }; |
| |
| template<char... _Digs> |
| struct _Parse_int |
| { |
| static constexpr unsigned long long |
| value{_Number<10U, _Digs...>::value}; |
| }; |
| |
| } // namespace __parse_int |
| |
| |
| namespace __select_int { |
| |
| template<unsigned long long _Val, typename... _Ints> |
| struct _Select_int_base; |
| |
| template<unsigned long long _Val, typename _IntType, typename... _Ints> |
| struct _Select_int_base<_Val, _IntType, _Ints...> |
| : integral_constant |
| < |
| typename conditional |
| < |
| _Val <= static_cast<unsigned long long> |
| (std::numeric_limits<_IntType>::max()), |
| _IntType, |
| typename _Select_int_base<_Val, _Ints...>::value_type |
| >::type, |
| _Val |
| > |
| { }; |
| |
| template<unsigned long long _Val> |
| struct _Select_int_base<_Val> : integral_constant<unsigned long long, _Val> |
| { }; |
| |
| template<char... _Digs> |
| struct _Select_int |
| : _Select_int_base< |
| __parse_int::_Parse_int<_Digs...>::value, |
| unsigned char, |
| unsigned short, |
| unsigned int, |
| unsigned long, |
| unsigned long long |
| > |
| { }; |
| |
| } // namespace __select_int |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace std |
| |
| #endif // __cplusplus > 201103L |
| |
| #endif // _PARSE_NUMBERS_H |