locale_classes.h revision 132720
1// Locale support -*- C++ -*- 2 3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 4// Free Software Foundation, Inc. 5// 6// This file is part of the GNU ISO C++ Library. This library is free 7// software; you can redistribute it and/or modify it under the 8// terms of the GNU General Public License as published by the 9// Free Software Foundation; either version 2, or (at your option) 10// any later version. 11 12// This library is distributed in the hope that it will be useful, 13// but WITHOUT ANY WARRANTY; without even the implied warranty of 14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15// GNU General Public License for more details. 16 17// You should have received a copy of the GNU General Public License along 18// with this library; see the file COPYING. If not, write to the Free 19// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 20// USA. 21 22// As a special exception, you may use this file as part of a free software 23// library without restriction. Specifically, if other files instantiate 24// templates or use macros or inline functions from this file, or you compile 25// this file and link it with other files to produce an executable, this 26// file does not by itself cause the resulting executable to be covered by 27// the GNU General Public License. This exception does not however 28// invalidate any other reasons why the executable file might be covered by 29// the GNU General Public License. 30 31// 32// ISO C++ 14882: 22.1 Locales 33// 34 35/** @file localefwd.h 36 * This is an internal header file, included by other library headers. 37 * You should not attempt to use it directly. 38 */ 39 40#ifndef _LOCALE_CLASSES_H 41#define _LOCALE_CLASSES_H 1 42 43#pragma GCC system_header 44 45#include <bits/localefwd.h> 46#include <cstring> // For strcmp. 47#include <string> 48#include <bits/atomicity.h> 49#include <bits/gthr.h> 50 51namespace std 52{ 53 // 22.1.1 Class locale 54 /** 55 * @brief Container class for localization functionality. 56 * 57 * The locale class is first a class wrapper for C library locales. It is 58 * also an extensible container for user-defined localization. A locale is 59 * a collection of facets that implement various localization features such 60 * as money, time, and number printing. 61 * 62 * Constructing C++ locales does not change the C library locale. 63 * 64 * This library supports efficient construction and copying of locales 65 * through a reference counting implementation of the locale class. 66 */ 67 class locale 68 { 69 public: 70 // Types: 71 /// Definition of locale::category. 72 typedef int category; 73 74 // Forward decls and friends: 75 class facet; 76 class id; 77 class _Impl; 78 79 friend class facet; 80 friend class _Impl; 81 82 template<typename _Facet> 83 friend bool 84 has_facet(const locale&) throw(); 85 86 template<typename _Facet> 87 friend const _Facet& 88 use_facet(const locale&); 89 90 template<typename _Cache> 91 friend struct __use_cache; 92 93 //@{ 94 /** 95 * @brief Category values. 96 * 97 * The standard category values are none, ctype, numeric, collate, time, 98 * monetary, and messages. They form a bitmask that supports union and 99 * intersection. The category all is the union of these values. 100 * 101 * @if maint 102 * NB: Order must match _S_facet_categories definition in locale.cc 103 * @endif 104 */ 105 static const category none = 0; 106 static const category ctype = 1L << 0; 107 static const category numeric = 1L << 1; 108 static const category collate = 1L << 2; 109 static const category time = 1L << 3; 110 static const category monetary = 1L << 4; 111 static const category messages = 1L << 5; 112 static const category all = (ctype | numeric | collate | 113 time | monetary | messages); 114 //@} 115 116 // Construct/copy/destroy: 117 118 /** 119 * @brief Default constructor. 120 * 121 * Constructs a copy of the global locale. If no locale has been 122 * explicitly set, this is the "C" locale. 123 */ 124 locale() throw(); 125 126 /** 127 * @brief Copy constructor. 128 * 129 * Constructs a copy of @a other. 130 * 131 * @param other The locale to copy. 132 */ 133 locale(const locale& __other) throw(); 134 135 /** 136 * @brief Named locale constructor. 137 * 138 * Constructs a copy of the named C library locale. 139 * 140 * @param s Name of the locale to construct. 141 * @throw std::runtime_error if s is null or an undefined locale. 142 */ 143 explicit 144 locale(const char* __s); 145 146 /** 147 * @brief Construct locale with facets from another locale. 148 * 149 * Constructs a copy of the locale @a base. The facets specified by @a 150 * cat are replaced with those from the locale named by @a s. If base is 151 * named, this locale instance will also be named. 152 * 153 * @param base The locale to copy. 154 * @param s Name of the locale to use facets from. 155 * @param cat Set of categories defining the facets to use from s. 156 * @throw std::runtime_error if s is null or an undefined locale. 157 */ 158 locale(const locale& __base, const char* __s, category __cat); 159 160 /** 161 * @brief Construct locale with facets from another locale. 162 * 163 * Constructs a copy of the locale @a base. The facets specified by @a 164 * cat are replaced with those from the locale @a add. If @a base and @a 165 * add are named, this locale instance will also be named. 166 * 167 * @param base The locale to copy. 168 * @param add The locale to use facets from. 169 * @param cat Set of categories defining the facets to use from add. 170 */ 171 locale(const locale& __base, const locale& __add, category __cat); 172 173 /** 174 * @brief Construct locale with another facet. 175 * 176 * Constructs a copy of the locale @a other. The facet @f is added to 177 * @other, replacing an existing facet of type Facet if there is one. If 178 * @f is null, this locale is a copy of @a other. 179 * 180 * @param other The locale to copy. 181 * @param f The facet to add in. 182 */ 183 template<typename _Facet> 184 locale(const locale& __other, _Facet* __f); 185 186 /// Locale destructor. 187 ~locale() throw(); 188 189 /** 190 * @brief Assignment operator. 191 * 192 * Set this locale to be a copy of @a other. 193 * 194 * @param other The locale to copy. 195 * @return A reference to this locale. 196 */ 197 const locale& 198 operator=(const locale& __other) throw(); 199 200 /** 201 * @brief Construct locale with another facet. 202 * 203 * Constructs and returns a new copy of this locale. Adds or replaces an 204 * existing facet of type Facet from the locale @a other into the new 205 * locale. 206 * 207 * @param Facet The facet type to copy from other 208 * @param other The locale to copy from. 209 * @return Newly constructed locale. 210 * @throw std::runtime_error if other has no facet of type Facet. 211 */ 212 template<typename _Facet> 213 locale 214 combine(const locale& __other) const; 215 216 // Locale operations: 217 /** 218 * @brief Return locale name. 219 * @return Locale name or "*" if unnamed. 220 */ 221 string 222 name() const; 223 224 /** 225 * @brief Locale equality. 226 * 227 * @param other The locale to compare against. 228 * @return True if other and this refer to the same locale instance, are 229 * copies, or have the same name. False otherwise. 230 */ 231 bool 232 operator==(const locale& __other) const throw (); 233 234 /** 235 * @brief Locale inequality. 236 * 237 * @param other The locale to compare against. 238 * @return ! (*this == other) 239 */ 240 inline bool 241 operator!=(const locale& __other) const throw () 242 { return !(this->operator==(__other)); } 243 244 /** 245 * @brief Compare two strings according to collate. 246 * 247 * Template operator to compare two strings using the compare function of 248 * the collate facet in this locale. One use is to provide the locale to 249 * the sort function. For example, a vector v of strings could be sorted 250 * according to locale loc by doing: 251 * @code 252 * std::sort(v.begin(), v.end(), loc); 253 * @endcode 254 * 255 * @param s1 First string to compare. 256 * @param s2 Second string to compare. 257 * @return True if collate<Char> facet compares s1 < s2, else false. 258 */ 259 template<typename _Char, typename _Traits, typename _Alloc> 260 bool 261 operator()(const basic_string<_Char, _Traits, _Alloc>& __s1, 262 const basic_string<_Char, _Traits, _Alloc>& __s2) const; 263 264 // Global locale objects: 265 /** 266 * @brief Set global locale 267 * 268 * This function sets the global locale to the argument and returns a 269 * copy of the previous global locale. If the argument has a name, it 270 * will also call std::setlocale(LC_ALL, loc.name()). 271 * 272 * @param locale The new locale to make global. 273 * @return Copy of the old global locale. 274 */ 275 static locale 276 global(const locale&); 277 278 /** 279 * @brief Return reference to the "C" locale. 280 */ 281 static const locale& 282 classic(); 283 284 private: 285 // The (shared) implementation 286 _Impl* _M_impl; 287 288 // The "C" reference locale 289 static _Impl* _S_classic; 290 291 // Current global locale 292 static _Impl* _S_global; 293 294 // Names of underlying locale categories. 295 // NB: locale::global() has to know how to modify all the 296 // underlying categories, not just the ones required by the C++ 297 // standard. 298 static const char* const* const _S_categories; 299 300 // Number of standard categories. For C++, these categories are 301 // collate, ctype, monetary, numeric, time, and messages. These 302 // directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE, 303 // LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE 304 // 1003.1-2001) specifies LC_MESSAGES. 305 // In addition to the standard categories, the underlying 306 // operating system is allowed to define extra LC_* 307 // macros. For GNU systems, the following are also valid: 308 // LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT, 309 // and LC_IDENTIFICATION. 310 static const size_t _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES; 311 312#ifdef __GTHREADS 313 static __gthread_once_t _S_once; 314#endif 315 316 explicit 317 locale(_Impl*) throw(); 318 319 static void 320 _S_initialize(); 321 322 static void 323 _S_initialize_once(); 324 325 static category 326 _S_normalize_category(category); 327 328 void 329 _M_coalesce(const locale& __base, const locale& __add, category __cat); 330 }; 331 332 333 // 22.1.1.1.2 Class locale::facet 334 /** 335 * @brief Localization functionality base class. 336 * 337 * The facet class is the base class for a localization feature, such as 338 * money, time, and number printing. It provides common support for facets 339 * and reference management. 340 * 341 * Facets may not be copied or assigned. 342 */ 343 class locale::facet 344 { 345 private: 346 friend class locale; 347 friend class locale::_Impl; 348 349 mutable _Atomic_word _M_refcount; 350 351 // Contains data from the underlying "C" library for the classic locale. 352 static __c_locale _S_c_locale; 353 354 // String literal for the name of the classic locale. 355 static const char _S_c_name[2]; 356 357#ifdef __GTHREADS 358 static __gthread_once_t _S_once; 359#endif 360 361 static void 362 _S_initialize_once(); 363 364 protected: 365 /** 366 * @brief Facet constructor. 367 * 368 * This is the constructor provided by the standard. If refs is 0, the 369 * facet is destroyed when the last referencing locale is destroyed. 370 * Otherwise the facet will never be destroyed. 371 * 372 * @param refs The initial value for reference count. 373 */ 374 explicit 375 facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0) 376 { } 377 378 /// Facet destructor. 379 virtual 380 ~facet(); 381 382 static void 383 _S_create_c_locale(__c_locale& __cloc, const char* __s, 384 __c_locale __old = 0); 385 386 static __c_locale 387 _S_clone_c_locale(__c_locale& __cloc); 388 389 static void 390 _S_destroy_c_locale(__c_locale& __cloc); 391 392 // Returns data from the underlying "C" library data for the 393 // classic locale. 394 static __c_locale 395 _S_get_c_locale(); 396 397 static const char* 398 _S_get_c_name(); 399 400 private: 401 inline void 402 _M_add_reference() const throw() 403 { __gnu_cxx::__atomic_add(&_M_refcount, 1); } 404 405 inline void 406 _M_remove_reference() const throw() 407 { 408 if (__gnu_cxx::__exchange_and_add(&_M_refcount, -1) == 1) 409 { 410 try 411 { delete this; } 412 catch (...) 413 { } 414 } 415 } 416 417 facet(const facet&); // Not defined. 418 419 facet& 420 operator=(const facet&); // Not defined. 421 }; 422 423 424 // 22.1.1.1.3 Class locale::id 425 /** 426 * @brief Facet ID class. 427 * 428 * The ID class provides facets with an index used to identify them. 429 * Every facet class must define a public static member locale::id, or be 430 * derived from a facet that provides this member, otherwise the facet 431 * cannot be used in a locale. The locale::id ensures that each class 432 * type gets a unique identifier. 433 */ 434 class locale::id 435 { 436 private: 437 friend class locale; 438 friend class locale::_Impl; 439 440 template<typename _Facet> 441 friend const _Facet& 442 use_facet(const locale&); 443 444 template<typename _Facet> 445 friend bool 446 has_facet(const locale&) throw (); 447 448 // NB: There is no accessor for _M_index because it may be used 449 // before the constructor is run; the effect of calling a member 450 // function (even an inline) would be undefined. 451 mutable size_t _M_index; 452 453 // Last id number assigned. 454 static _Atomic_word _S_refcount; 455 456 void 457 operator=(const id&); // Not defined. 458 459 id(const id&); // Not defined. 460 461 public: 462 // NB: This class is always a static data member, and thus can be 463 // counted on to be zero-initialized. 464 /// Constructor. 465 id() { } 466 467 size_t 468 _M_id() const; 469 }; 470 471 472 // Implementation object for locale. 473 class locale::_Impl 474 { 475 public: 476 // Friends. 477 friend class locale; 478 friend class locale::facet; 479 480 template<typename _Facet> 481 friend bool 482 has_facet(const locale&) throw(); 483 484 template<typename _Facet> 485 friend const _Facet& 486 use_facet(const locale&); 487 488 template<typename _Cache> 489 friend struct __use_cache; 490 491 private: 492 // Data Members. 493 _Atomic_word _M_refcount; 494 const facet** _M_facets; 495 size_t _M_facets_size; 496 const facet** _M_caches; 497 char** _M_names; 498 static const locale::id* const _S_id_ctype[]; 499 static const locale::id* const _S_id_numeric[]; 500 static const locale::id* const _S_id_collate[]; 501 static const locale::id* const _S_id_time[]; 502 static const locale::id* const _S_id_monetary[]; 503 static const locale::id* const _S_id_messages[]; 504 static const locale::id* const* const _S_facet_categories[]; 505 506 inline void 507 _M_add_reference() throw() 508 { __gnu_cxx::__atomic_add(&_M_refcount, 1); } 509 510 inline void 511 _M_remove_reference() throw() 512 { 513 if (__gnu_cxx::__exchange_and_add(&_M_refcount, -1) == 1) 514 { 515 try 516 { delete this; } 517 catch(...) 518 { } 519 } 520 } 521 522 _Impl(const _Impl&, size_t); 523 _Impl(const char*, size_t); 524 _Impl(size_t) throw(); 525 526 ~_Impl() throw(); 527 528 _Impl(const _Impl&); // Not defined. 529 530 void 531 operator=(const _Impl&); // Not defined. 532 533 inline bool 534 _M_check_same_name() 535 { 536 bool __ret = true; 537 for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i) 538 __ret = std::strcmp(_M_names[__i], _M_names[__i + 1]) == 0; 539 return __ret; 540 } 541 542 void 543 _M_replace_categories(const _Impl*, category); 544 545 void 546 _M_replace_category(const _Impl*, const locale::id* const*); 547 548 void 549 _M_replace_facet(const _Impl*, const locale::id*); 550 551 void 552 _M_install_facet(const locale::id*, const facet*); 553 554 template<typename _Facet> 555 inline void 556 _M_init_facet(_Facet* __facet) 557 { _M_install_facet(&_Facet::id, __facet); } 558 559 void 560 _M_install_cache(const facet* __cache, size_t __index) throw() 561 { 562 __cache->_M_add_reference(); 563 _M_caches[__index] = __cache; 564 } 565 }; 566 567 template<typename _Facet> 568 locale::locale(const locale& __other, _Facet* __f) 569 { 570 _M_impl = new _Impl(*__other._M_impl, 1); 571 572 char* _M_tmp_names[_S_categories_size]; 573 size_t __i = 0; 574 try 575 { 576 for (; __i < _S_categories_size; ++__i) 577 { 578 _M_tmp_names[__i] = new char[2]; 579 std::strcpy(_M_tmp_names[__i], "*"); 580 } 581 _M_impl->_M_install_facet(&_Facet::id, __f); 582 } 583 catch(...) 584 { 585 _M_impl->_M_remove_reference(); 586 for (size_t __j = 0; __j < __i; ++__j) 587 delete [] _M_tmp_names[__j]; 588 __throw_exception_again; 589 } 590 591 for (size_t __k = 0; __k < _S_categories_size; ++__k) 592 { 593 delete [] _M_impl->_M_names[__k]; 594 _M_impl->_M_names[__k] = _M_tmp_names[__k]; 595 } 596 } 597} // namespace std 598 599#endif 600