Where Online Learning is simpler!
The C and C++ Include Header Files
cat -n /usr/include/c++/15/tr2/bool_set
1 // TR2 <bool_set> -*- C++ -*- 2 3 // Copyright (C) 2009-2025 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 tr2/bool_set 26 * This is a TR2 C++ Library header. 27 */ 28 29 #ifndef _GLIBCXX_TR2_BOOL_SET 30 #define _GLIBCXX_TR2_BOOL_SET 1 31 32 #ifdef _GLIBCXX_SYSHDR 33 #pragma GCC system_header 34 #endif 35 36 #include <typeinfo> 37 #include <iostream> 38 39 namespace std _GLIBCXX_VISIBILITY(default) 40 { 41 _GLIBCXX_BEGIN_NAMESPACE_VERSION 42 43 namespace tr2 44 { 45 /** 46 * bool_set 47 * 48 * See N2136, Bool_set: multi-valued logic 49 * by Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion. 50 * 51 * The implicit conversion to bool is slippery! I may use the new 52 * explicit conversion. This has been specialized in the language 53 * so that in contexts requiring a bool the conversion happens 54 * implicitly. Thus most objections should be eliminated. 55 */ 56 class bool_set 57 { 58 public: 59 60 /// Default constructor. 61 constexpr bool_set() : _M_b(_S_false) { } 62 63 /// Constructor from bool. 64 constexpr bool_set(bool __t) : _M_b(_Bool_set_val(__t)) { } 65 66 // I'm not sure about this. 67 bool contains(bool_set __b) const 68 { return this->is_singleton() && this->equals(__b); } 69 70 /// Return true if states are equal. 71 bool equals(bool_set __b) const 72 { return __b._M_b == _M_b; } 73 74 /// Return true if this is empty. 75 bool is_emptyset() const 76 { return _M_b == _S_empty; } 77 78 /// Return true if this is indeterminate. 79 bool is_indeterminate() const 80 { return _M_b == _S_indet; } 81 82 /// Return true if this is false or true (normal boolean). 83 bool is_singleton() const 84 { return _M_b == _S_false || _M_b == _S_true_; } 85 86 /// Conversion to bool. 87 //explicit 88 operator bool() const 89 { 90 if (! is_singleton()) 91 throw std::bad_cast(); 92 return _M_b; 93 } 94 95 /// 96 static bool_set indeterminate() 97 { 98 bool_set __b; 99 __b._M_b = _S_indet; 100 return __b; 101 } 102 103 /// 104 static bool_set emptyset() 105 { 106 bool_set __b; 107 __b._M_b = _S_empty; 108 return __b; 109 } 110 111 friend bool_set 112 operator!(bool_set __b) 113 { return __b._M_not(); } 114 115 friend bool_set 116 operator^(bool_set __s, bool_set __t) 117 { return __s._M_xor(__t); } 118 119 friend bool_set 120 operator|(bool_set __s, bool_set __t) 121 { return __s._M_or(__t); } 122 123 friend bool_set 124 operator&(bool_set __s, bool_set __t) 125 { return __s._M_and(__t); } 126 127 friend bool_set 128 operator==(bool_set __s, bool_set __t) 129 { return __s._M_eq(__t); } 130 131 132 // These overloads replace the facet additions in the paper! 133 134 template<typename CharT, typename Traits> 135 friend std::basic_ostream<CharT, Traits>& 136 operator<<(std::basic_ostream<CharT, Traits>& __out, bool_set __b) 137 { 138 int __a = __b._M_b; 139 __out << __a; 140 } 141 142 template<typename CharT, typename Traits> 143 friend std::basic_istream<CharT, Traits>& 144 operator>>(std::basic_istream<CharT, Traits>& __in, bool_set& __b) 145 { 146 long __c; 147 __in >> __c; 148 if (__c >= _S_false && __c < _S_empty) 149 __b._M_b = static_cast<_Bool_set_val>(__c); 150 } 151 152 private: 153 154 /// 155 enum _Bool_set_val: unsigned char 156 { 157 _S_false = 0, 158 _S_true_ = 1, 159 _S_indet = 2, 160 _S_empty = 3 161 }; 162 163 /// Bool set state. 164 _Bool_set_val _M_b; 165 166 /// 167 bool_set(_Bool_set_val __c) : _M_b(__c) { } 168 169 /// 170 bool_set _M_not() const 171 { return _S_not[this->_M_b]; } 172 173 /// 174 bool_set _M_xor(bool_set __b) const 175 { return _S_xor[this->_M_b][__b._M_b]; } 176 177 /// 178 bool_set _M_or(bool_set __b) const 179 { return _S_or[this->_M_b][__b._M_b]; } 180 181 /// 182 bool_set _M_and(bool_set __b) const 183 { return _S_and[this->_M_b][__b._M_b]; } 184 185 /// 186 bool_set _M_eq(bool_set __b) const 187 { return _S_eq[this->_M_b][__b._M_b]; } 188 189 /// 190 static _Bool_set_val _S_not[4]; 191 192 /// 193 static _Bool_set_val _S_xor[4][4]; 194 195 /// 196 static _Bool_set_val _S_or[4][4]; 197 198 /// 199 static _Bool_set_val _S_and[4][4]; 200 201 /// 202 static _Bool_set_val _S_eq[4][4]; 203 }; 204 205 // 20.2.3.2 bool_set values 206 207 inline bool 208 contains(bool_set __s, bool_set __t) 209 { return __s.contains(__t); } 210 211 inline bool 212 equals(bool_set __s, bool_set __t) 213 { return __s.equals(__t); } 214 215 inline bool 216 is_emptyset(bool_set __b) 217 { return __b.is_emptyset(); } 218 219 inline bool 220 is_indeterminate(bool_set __b) 221 { return __b.is_indeterminate(); } 222 223 inline bool 224 is_singleton(bool_set __b) 225 { return __b.is_singleton(); } 226 227 inline bool 228 certainly(bool_set __b) 229 { return ! __b.contains(false); } 230 231 inline bool 232 possibly(bool_set __b) 233 { return __b.contains(true); } 234 235 236 // 20.2.3.3 bool_set set operations 237 238 inline bool_set 239 set_union(bool __s, bool_set __t) 240 { return bool_set(__s) | __t; } 241 242 inline bool_set 243 set_union(bool_set __s, bool __t) 244 { return __s | bool_set(__t); } 245 246 inline bool_set 247 set_union(bool_set __s, bool_set __t) 248 { return __s | __t; } 249 250 inline bool_set 251 set_intersection(bool __s, bool_set __t) 252 { return bool_set(__s) & __t; } 253 254 inline bool_set 255 set_intersection(bool_set __s, bool __t) 256 { return __s & bool_set(__t); } 257 258 inline bool_set 259 set_intersection(bool_set __s, bool_set __t) 260 { return __s & __t; } 261 262 inline bool_set 263 set_complement(bool_set __b) 264 { return ! __b; } 265 266 267 // 20.2.3.4 bool_set logical operators 268 269 inline bool_set 270 operator^(bool __s, bool_set __t) 271 { return bool_set(__s) ^ __t; } 272 273 inline bool_set 274 operator^(bool_set __s, bool __t) 275 { return __s ^ bool_set(__t); } 276 277 inline bool_set 278 operator|(bool __s, bool_set __t) 279 { return bool_set(__s) | __t; } 280 281 inline bool_set 282 operator|(bool_set __s, bool __t) 283 { return __s | bool_set(__t); } 284 285 inline bool_set 286 operator&(bool __s, bool_set __t) 287 { return bool_set(__s) & __t; } 288 289 inline bool_set 290 operator&(bool_set __s, bool __t) 291 { return __s & bool_set(__t); } 292 293 294 // 20.2.3.5 bool_set relational operators 295 296 inline bool_set 297 operator==(bool __s, bool_set __t) 298 { return bool_set(__s) == __t; } 299 300 inline bool_set 301 operator==(bool_set __s, bool __t) 302 { return __s == bool_set(__t); } 303 304 inline bool_set 305 operator!=(bool __s, bool_set __t) 306 { return ! (__s == __t); } 307 308 inline bool_set 309 operator!=(bool_set __s, bool __t) 310 { return ! (__s == __t); } 311 312 inline bool_set 313 operator!=(bool_set __s, bool_set __t) 314 { return ! (__s == __t); } 315 } 316 317 _GLIBCXX_END_NAMESPACE_VERSION 318 } 319 320 #include <tr2/bool_set.tcc> 321 322 #endif // _GLIBCXX_TR2_BOOL_SET
