| 1 |
// Components for compile-time parsing of numbers -*- C++ -*- |
| 2 |
|
| 3 |
// Copyright (C) 2013-2021 Free Software Foundation, Inc. |
| 4 |
// |
| 5 |
// This file is part of the GNU ISO C++ Library. This library is free |
| 6 |
// software; you can redistribute it and/or modify it under the |
| 7 |
// terms of the GNU General Public License as published by the |
| 8 |
// Free Software Foundation; either version 3, or (at your option) |
| 9 |
// any later version. |
| 10 |
|
| 11 |
// This library is distributed in the hope that it will be useful, |
| 12 |
// but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 |
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 |
// GNU General Public License for more details. |
| 15 |
|
| 16 |
// Under Section 7 of GPL version 3, you are granted additional |
| 17 |
// permissions described in the GCC Runtime Library Exception, version |
| 18 |
// 3.1, as published by the Free Software Foundation. |
| 19 |
|
| 20 |
// You should have received a copy of the GNU General Public License and |
| 21 |
// a copy of the GCC Runtime Library Exception along with this program; |
| 22 |
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| 23 |
// <http://www.gnu.org/licenses/>. |
| 24 |
|
| 25 |
/** @file bits/parse_numbers.h |
| 26 |
* This is an internal header file, included by other library headers. |
| 27 |
* Do not attempt to use it directly. @headername{chrono} |
| 28 |
*/ |
| 29 |
|
| 30 |
#ifndef _GLIBCXX_PARSE_NUMBERS_H |
| 31 |
#define _GLIBCXX_PARSE_NUMBERS_H 1 |
| 32 |
|
| 33 |
#pragma GCC system_header |
| 34 |
|
| 35 |
// From n3642.pdf except I added binary literals and digit separator '\''. |
| 36 |
|
| 37 |
#if __cplusplus >= 201402L |
| 38 |
|
| 39 |
#include <type_traits> |
| 40 |
#include <ext/numeric_traits.h> |
| 41 |
|
| 42 |
namespace std _GLIBCXX_VISIBILITY(default) |
| 43 |
{ |
| 44 |
_GLIBCXX_BEGIN_NAMESPACE_VERSION |
| 45 |
|
| 46 |
namespace __parse_int |
| 47 |
{ |
| 48 |
template<unsigned _Base, char _Dig> |
| 49 |
struct _Digit; |
| 50 |
|
| 51 |
template<unsigned _Base> |
| 52 |
struct _Digit<_Base, '0'> : integral_constant<unsigned, 0> |
| 53 |
{ |
| 54 |
using __valid = true_type; |
| 55 |
}; |
| 56 |
|
| 57 |
template<unsigned _Base> |
| 58 |
struct _Digit<_Base, '1'> : integral_constant<unsigned, 1> |
| 59 |
{ |
| 60 |
using __valid = true_type; |
| 61 |
}; |
| 62 |
|
| 63 |
template<unsigned _Base, unsigned _Val> |
| 64 |
struct _Digit_impl : integral_constant<unsigned, _Val> |
| 65 |
{ |
| 66 |
static_assert(_Base > _Val, "invalid digit"); |
| 67 |
using __valid = true_type; |
| 68 |
}; |
| 69 |
|
| 70 |
template<unsigned _Base> |
| 71 |
struct _Digit<_Base, '2'> : _Digit_impl<_Base, 2> |
| 72 |
{ }; |
| 73 |
|
| 74 |
template<unsigned _Base> |
| 75 |
struct _Digit<_Base, '3'> : _Digit_impl<_Base, 3> |
| 76 |
{ }; |
| 77 |
|
| 78 |
template<unsigned _Base> |
| 79 |
struct _Digit<_Base, '4'> : _Digit_impl<_Base, 4> |
| 80 |
{ }; |
| 81 |
|
| 82 |
template<unsigned _Base> |
| 83 |
struct _Digit<_Base, '5'> : _Digit_impl<_Base, 5> |
| 84 |
{ }; |
| 85 |
|
| 86 |
template<unsigned _Base> |
| 87 |
struct _Digit<_Base, '6'> : _Digit_impl<_Base, 6> |
| 88 |
{ }; |
| 89 |
|
| 90 |
template<unsigned _Base> |
| 91 |
struct _Digit<_Base, '7'> : _Digit_impl<_Base, 7> |
| 92 |
{ }; |
| 93 |
|
| 94 |
template<unsigned _Base> |
| 95 |
struct _Digit<_Base, '8'> : _Digit_impl<_Base, 8> |
| 96 |
{ }; |
| 97 |
|
| 98 |
template<unsigned _Base> |
| 99 |
struct _Digit<_Base, '9'> : _Digit_impl<_Base, 9> |
| 100 |
{ }; |
| 101 |
|
| 102 |
template<unsigned _Base> |
| 103 |
struct _Digit<_Base, 'a'> : _Digit_impl<_Base, 0xa> |
| 104 |
{ }; |
| 105 |
|
| 106 |
template<unsigned _Base> |
| 107 |
struct _Digit<_Base, 'A'> : _Digit_impl<_Base, 0xa> |
| 108 |
{ }; |
| 109 |
|
| 110 |
template<unsigned _Base> |
| 111 |
struct _Digit<_Base, 'b'> : _Digit_impl<_Base, 0xb> |
| 112 |
{ }; |
| 113 |
|
| 114 |
template<unsigned _Base> |
| 115 |
struct _Digit<_Base, 'B'> : _Digit_impl<_Base, 0xb> |
| 116 |
{ }; |
| 117 |
|
| 118 |
template<unsigned _Base> |
| 119 |
struct _Digit<_Base, 'c'> : _Digit_impl<_Base, 0xc> |
| 120 |
{ }; |
| 121 |
|
| 122 |
template<unsigned _Base> |
| 123 |
struct _Digit<_Base, 'C'> : _Digit_impl<_Base, 0xc> |
| 124 |
{ }; |
| 125 |
|
| 126 |
template<unsigned _Base> |
| 127 |
struct _Digit<_Base, 'd'> : _Digit_impl<_Base, 0xd> |
| 128 |
{ }; |
| 129 |
|
| 130 |
template<unsigned _Base> |
| 131 |
struct _Digit<_Base, 'D'> : _Digit_impl<_Base, 0xd> |
| 132 |
{ }; |
| 133 |
|
| 134 |
template<unsigned _Base> |
| 135 |
struct _Digit<_Base, 'e'> : _Digit_impl<_Base, 0xe> |
| 136 |
{ }; |
| 137 |
|
| 138 |
template<unsigned _Base> |
| 139 |
struct _Digit<_Base, 'E'> : _Digit_impl<_Base, 0xe> |
| 140 |
{ }; |
| 141 |
|
| 142 |
template<unsigned _Base> |
| 143 |
struct _Digit<_Base, 'f'> : _Digit_impl<_Base, 0xf> |
| 144 |
{ }; |
| 145 |
|
| 146 |
template<unsigned _Base> |
| 147 |
struct _Digit<_Base, 'F'> : _Digit_impl<_Base, 0xf> |
| 148 |
{ }; |
| 149 |
|
| 150 |
// Digit separator |
| 151 |
template<unsigned _Base> |
| 152 |
struct _Digit<_Base, '\''> : integral_constant<unsigned, 0> |
| 153 |
{ |
| 154 |
using __valid = false_type; |
| 155 |
}; |
| 156 |
|
| 157 |
//------------------------------------------------------------------------------ |
| 158 |
|
| 159 |
template<unsigned long long _Val> |
| 160 |
using __ull_constant = integral_constant<unsigned long long, _Val>; |
| 161 |
|
| 162 |
template<unsigned _Base, char _Dig, char... _Digs> |
| 163 |
struct _Power_help |
| 164 |
{ |
| 165 |
using __next = typename _Power_help<_Base, _Digs...>::type; |
| 166 |
using __valid_digit = typename _Digit<_Base, _Dig>::__valid; |
| 167 |
using type |
| 168 |
= __ull_constant<__next::value * (__valid_digit{} ? _Base : 1ULL)>; |
| 169 |
}; |
| 170 |
|
| 171 |
template<unsigned _Base, char _Dig> |
| 172 |
struct _Power_help<_Base, _Dig> |
| 173 |
{ |
| 174 |
using __valid_digit = typename _Digit<_Base, _Dig>::__valid; |
| 175 |
using type = __ull_constant<__valid_digit::value>; |
| 176 |
}; |
| 177 |
|
| 178 |
template<unsigned _Base, char... _Digs> |
| 179 |
struct _Power : _Power_help<_Base, _Digs...>::type |
| 180 |
{ }; |
| 181 |
|
| 182 |
template<unsigned _Base> |
| 183 |
struct _Power<_Base> : __ull_constant<0> |
| 184 |
{ }; |
| 185 |
|
| 186 |
//------------------------------------------------------------------------------ |
| 187 |
|
| 188 |
template<unsigned _Base, unsigned long long _Pow, char _Dig, char... _Digs> |
| 189 |
struct _Number_help |
| 190 |
{ |
| 191 |
using __digit = _Digit<_Base, _Dig>; |
| 192 |
using __valid_digit = typename __digit::__valid; |
| 193 |
using __next = _Number_help<_Base, |
| 194 |
__valid_digit::value ? _Pow / _Base : _Pow, |
| 195 |
_Digs...>; |
| 196 |
using type = __ull_constant<_Pow * __digit::value + __next::type::value>; |
| 197 |
static_assert((type::value / _Pow) == __digit::value, |
| 198 |
"integer literal does not fit in unsigned long long"); |
| 199 |
}; |
| 200 |
|
| 201 |
// Skip past digit separators: |
| 202 |
template<unsigned _Base, unsigned long long _Pow, char _Dig, char..._Digs> |
| 203 |
struct _Number_help<_Base, _Pow, '\'', _Dig, _Digs...> |
| 204 |
: _Number_help<_Base, _Pow, _Dig, _Digs...> |
| 205 |
{ }; |
| 206 |
|
| 207 |
// Terminating case for recursion: |
| 208 |
template<unsigned _Base, char _Dig> |
| 209 |
struct _Number_help<_Base, 1ULL, _Dig> |
| 210 |
{ |
| 211 |
using type = __ull_constant<_Digit<_Base, _Dig>::value>; |
| 212 |
}; |
| 213 |
|
| 214 |
template<unsigned _Base, char... _Digs> |
| 215 |
struct _Number |
| 216 |
: _Number_help<_Base, _Power<_Base, _Digs...>::value, _Digs...>::type |
| 217 |
{ }; |
| 218 |
|
| 219 |
template<unsigned _Base> |
| 220 |
struct _Number<_Base> |
| 221 |
: __ull_constant<0> |
| 222 |
{ }; |
| 223 |
|
| 224 |
//------------------------------------------------------------------------------ |
| 225 |
|
| 226 |
template<char... _Digs> |
| 227 |
struct _Parse_int; |
| 228 |
|
| 229 |
template<char... _Digs> |
| 230 |
struct _Parse_int<'0', 'b', _Digs...> |
| 231 |
: _Number<2U, _Digs...>::type |
| 232 |
{ }; |
| 233 |
|
| 234 |
template<char... _Digs> |
| 235 |
struct _Parse_int<'0', 'B', _Digs...> |
| 236 |
: _Number<2U, _Digs...>::type |
| 237 |
{ }; |
| 238 |
|
| 239 |
template<char... _Digs> |
| 240 |
struct _Parse_int<'0', 'x', _Digs...> |
| 241 |
: _Number<16U, _Digs...>::type |
| 242 |
{ }; |
| 243 |
|
| 244 |
template<char... _Digs> |
| 245 |
struct _Parse_int<'0', 'X', _Digs...> |
| 246 |
: _Number<16U, _Digs...>::type |
| 247 |
{ }; |
| 248 |
|
| 249 |
template<char... _Digs> |
| 250 |
struct _Parse_int<'0', _Digs...> |
| 251 |
: _Number<8U, _Digs...>::type |
| 252 |
{ }; |
| 253 |
|
| 254 |
template<char... _Digs> |
| 255 |
struct _Parse_int |
| 256 |
: _Number<10U, _Digs...>::type |
| 257 |
{ }; |
| 258 |
|
| 259 |
} // namespace __parse_int |
| 260 |
|
| 261 |
|
| 262 |
namespace __select_int |
| 263 |
{ |
| 264 |
template<unsigned long long _Val, typename... _Ints> |
| 265 |
struct _Select_int_base; |
| 266 |
|
| 267 |
template<unsigned long long _Val, typename _IntType, typename... _Ints> |
| 268 |
struct _Select_int_base<_Val, _IntType, _Ints...> |
| 269 |
: conditional_t<(_Val <= __gnu_cxx::__int_traits<_IntType>::__max), |
| 270 |
integral_constant<_IntType, (_IntType)_Val>, |
| 271 |
_Select_int_base<_Val, _Ints...>> |
| 272 |
{ }; |
| 273 |
|
| 274 |
template<unsigned long long _Val> |
| 275 |
struct _Select_int_base<_Val> |
| 276 |
{ }; |
| 277 |
|
| 278 |
template<char... _Digs> |
| 279 |
using _Select_int = typename _Select_int_base< |
| 280 |
__parse_int::_Parse_int<_Digs...>::value, |
| 281 |
unsigned char, |
| 282 |
unsigned short, |
| 283 |
unsigned int, |
| 284 |
unsigned long, |
| 285 |
unsigned long long |
| 286 |
>::type; |
| 287 |
|
| 288 |
} // namespace __select_int |
| 289 |
|
| 290 |
_GLIBCXX_END_NAMESPACE_VERSION |
| 291 |
} // namespace std |
| 292 |
|
| 293 |
#endif // C++14 |
| 294 |
|
| 295 |
#endif // _GLIBCXX_PARSE_NUMBERS_H |
