1 // TR2 <bool_set> -*- C++ -*- 2 3 // Copyright (C) 2009-2013 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 #pragma GCC system_header 33 34 #include <typeinfo> 35 #include <iostream> 36 37 namespace std _GLIBCXX_VISIBILITY(default) 38 { 39 namespace tr2 40 { 41 _GLIBCXX_BEGIN_NAMESPACE_VERSION 42 43 /** 44 * bool_set 45 * 46 * See N2136, Bool_set: multi-valued logic 47 * by Herv Brnnimann, Guillaume Melquiond, Sylvain Pion. 48 * 49 * The implicit conversion to bool is slippery! I may use the new 50 * explicit conversion. This has been specialized in the language 51 * so that in contexts requiring a bool the conversion happens 52 * implicitly. Thus most objections should be eliminated. 53 */ 54 class bool_set 55 { 56 public: 57 58 /// Default constructor. 59 constexpr bool_set() : _M_b(_S_false) { } 60 61 /// Constructor from bool. 62 constexpr bool_set(bool __t) : _M_b(_Bool_set_val(__t)) { } 63 64 // I'm not sure about this. 65 bool contains(bool_set __b) const 66 { return this->is_singleton() && this->equals(__b); } 67 68 /// Return true if states are equal. 69 bool equals(bool_set __b) const 70 { return __b._M_b == _M_b; } 71 72 /// Return true if this is empty. 73 bool is_emptyset() const 74 { return _M_b == _S_empty; } 75 76 /// Return true if this is indeterminate. 77 bool is_indeterminate() const 78 { return _M_b == _S_indet; } 79 80 /// Return true if this is false or true (normal boolean). 81 bool is_singleton() const 82 { return _M_b == _S_false || _M_b == _S_true_; } 83 84 /// Conversion to bool. 85 //explicit 86 operator bool() const 87 { 88 if (! is_singleton()) 89 throw std::bad_cast(); 90 return _M_b; 91 } 92 93 /// 94 static bool_set indeterminate() 95 { 96 bool_set __b; 97 __b._M_b = _S_indet; 98 return __b; 99 } 100 101 /// 102 static bool_set emptyset() 103 { 104 bool_set __b; 105 __b._M_b = _S_empty; 106 return __b; 107 } 108 109 friend bool_set 110 operator!(bool_set __b) 111 { return __b._M_not(); } 112 113 friend bool_set 114 operator^(bool_set __s, bool_set __t) 115 { return __s._M_xor(__t); } 116 117 friend bool_set 118 operator|(bool_set __s, bool_set __t) 119 { return __s._M_or(__t); } 120 121 friend bool_set 122 operator&(bool_set __s, bool_set __t) 123 { return __s._M_and(__t); } 124 125 friend bool_set 126 operator==(bool_set __s, bool_set __t) 127 { return __s._M_eq(__t); } 128 129 130 // These overloads replace the facet additions in the paper! 131 132 template<typename CharT, typename Traits> 133 friend std::basic_ostream<CharT, Traits>& 134 operator<<(std::basic_ostream<CharT, Traits>& __out, bool_set __b) 135 { 136 int __a = __b._M_b; 137 __out << __a; 138 } 139 140 template<typename CharT, typename Traits> 141 friend std::basic_istream<CharT, Traits>& 142 operator>>(std::basic_istream<CharT, Traits>& __in, bool_set& __b) 143 { 144 long __c; 145 __in >> __c; 146 if (__c >= _S_false && __c < _S_empty) 147 __b._M_b = static_cast<_Bool_set_val>(__c); 148 } 149 150 private: 151 152 /// 153 enum _Bool_set_val: unsigned char 154 { 155 _S_false = 0, 156 _S_true_ = 1, 157 _S_indet = 2, 158 _S_empty = 3 159 }; 160 161 /// Bool set state. 162 _Bool_set_val _M_b; 163 164 /// 165 bool_set(_Bool_set_val __c) : _M_b(__c) { } 166 167 /// 168 bool_set _M_not() const 169 { return _S_not[this->_M_b]; } 170 171 /// 172 bool_set _M_xor(bool_set __b) const 173 { return _S_xor[this->_M_b][__b._M_b]; } 174 175 /// 176 bool_set _M_or(bool_set __b) const 177 { return _S_or[this->_M_b][__b._M_b]; } 178 179 /// 180 bool_set _M_and(bool_set __b) const 181 { return _S_and[this->_M_b][__b._M_b]; } 182 183 /// 184 bool_set _M_eq(bool_set __b) const 185 { return _S_eq[this->_M_b][__b._M_b]; } 186 187 /// 188 static _Bool_set_val _S_not[4]; 189 190 /// 191 static _Bool_set_val _S_xor[4][4]; 192 193 /// 194 static _Bool_set_val _S_or[4][4]; 195 196 /// 197 static _Bool_set_val _S_and[4][4]; 198 199 /// 200 static _Bool_set_val _S_eq[4][4]; 201 }; 202 203 // 20.2.3.2 bool_set values 204 205 inline bool 206 contains(bool_set __s, bool_set __t) 207 { return __s.contains(__t); } 208 209 inline bool 210 equals(bool_set __s, bool_set __t) 211 { return __s.equals(__t); } 212 213 inline bool 214 is_emptyset(bool_set __b) 215 { return __b.is_emptyset(); } 216 217 inline bool 218 is_indeterminate(bool_set __b) 219 { return __b.is_indeterminate(); } 220 221 inline bool 222 is_singleton(bool_set __b) 223 { return __b.is_singleton(); } 224 225 inline bool 226 certainly(bool_set __b) 227 { return ! __b.contains(false); } 228 229 inline bool 230 possibly(bool_set __b) 231 { return __b.contains(true); } 232 233 234 // 20.2.3.3 bool_set set operations 235 236 inline bool_set 237 set_union(bool __s, bool_set __t) 238 { return bool_set(__s) | __t; } 239 240 inline bool_set 241 set_union(bool_set __s, bool __t) 242 { return __s | bool_set(__t); } 243 244 inline bool_set 245 set_union(bool_set __s, bool_set __t) 246 { return __s | __t; } 247 248 inline bool_set 249 set_intersection(bool __s, bool_set __t) 250 { return bool_set(__s) & __t; } 251 252 inline bool_set 253 set_intersection(bool_set __s, bool __t) 254 { return __s & bool_set(__t); } 255 256 inline bool_set 257 set_intersection(bool_set __s, bool_set __t) 258 { return __s & __t; } 259 260 inline bool_set 261 set_complement(bool_set __b) 262 { return ! __b; } 263 264 265 // 20.2.3.4 bool_set logical operators 266 267 inline bool_set 268 operator^(bool __s, bool_set __t) 269 { return bool_set(__s) ^ __t; } 270 271 inline bool_set 272 operator^(bool_set __s, bool __t) 273 { return __s ^ bool_set(__t); } 274 275 inline bool_set 276 operator|(bool __s, bool_set __t) 277 { return bool_set(__s) | __t; } 278 279 inline bool_set 280 operator|(bool_set __s, bool __t) 281 { return __s | bool_set(__t); } 282 283 inline bool_set 284 operator&(bool __s, bool_set __t) 285 { return bool_set(__s) & __t; } 286 287 inline bool_set 288 operator&(bool_set __s, bool __t) 289 { return __s & bool_set(__t); } 290 291 292 // 20.2.3.5 bool_set relational operators 293 294 inline bool_set 295 operator==(bool __s, bool_set __t) 296 { return bool_set(__s) == __t; } 297 298 inline bool_set 299 operator==(bool_set __s, bool __t) 300 { return __s == bool_set(__t); } 301 302 inline bool_set 303 operator!=(bool __s, bool_set __t) 304 { return ! (__s == __t); } 305 306 inline bool_set 307 operator!=(bool_set __s, bool __t) 308 { return ! (__s == __t); } 309 310 inline bool_set 311 operator!=(bool_set __s, bool_set __t) 312 { return ! (__s == __t); } 313 314 _GLIBCXX_END_NAMESPACE_VERSION 315 } 316 } 317 318 #include <tr2/bool_set.tcc> 319 320 #endif // _GLIBCXX_TR2_BOOL_SET 321
