1// File based streams -*- C++ -*- 2 3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 4// 2006, 2007, 2008, 2009, 2010 5// Free Software Foundation, Inc. 6// 7// This file is part of the GNU ISO C++ Library. This library is free 8// software; you can redistribute it and/or modify it under the 9// terms of the GNU General Public License as published by the 10// Free Software Foundation; either version 3, or (at your option) 11// any later version. 12 13// This library is distributed in the hope that it will be useful, 14// but WITHOUT ANY WARRANTY; without even the implied warranty of 15// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16// GNU General Public License for more details. 17 18// Under Section 7 of GPL version 3, you are granted additional 19// permissions described in the GCC Runtime Library Exception, version 20// 3.1, as published by the Free Software Foundation. 21 22// You should have received a copy of the GNU General Public License and 23// a copy of the GCC Runtime Library Exception along with this program; 24// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 25// <http://www.gnu.org/licenses/>. 26 27/** @file fstream 28 * This is a Standard C++ Library header. 29 */ 30 31// 32// ISO C++ 14882: 27.8 File-based streams 33// 34 35#ifndef _GLIBCXX_FSTREAM 36#define _GLIBCXX_FSTREAM 1 37 38#pragma GCC system_header 39 40#include <istream> 41#include <ostream> 42#include <bits/codecvt.h> 43#include <cstdio> // For BUFSIZ 44#include <bits/basic_file.h> // For __basic_file, __c_lock 45#ifdef __GXX_EXPERIMENTAL_CXX0X__ 46#include <string> // For std::string overloads. 47#endif 48 49_GLIBCXX_BEGIN_NAMESPACE(std) 50 51 // [27.8.1.1] template class basic_filebuf 52 /** 53 * @brief The actual work of input and output (for files). 54 * @ingroup io 55 * 56 * This class associates both its input and output sequence with an 57 * external disk file, and maintains a joint file position for both 58 * sequences. Many of its semantics are described in terms of similar 59 * behavior in the Standard C Library's @c FILE streams. 60 */ 61 // Requirements on traits_type, specific to this class: 62 // traits_type::pos_type must be fpos<traits_type::state_type> 63 // traits_type::off_type must be streamoff 64 // traits_type::state_type must be Assignable and DefaultConstructible, 65 // and traits_type::state_type() must be the initial state for codecvt. 66 template<typename _CharT, typename _Traits> 67 class basic_filebuf : public basic_streambuf<_CharT, _Traits> 68 { 69 public: 70 // Types: 71 typedef _CharT char_type; 72 typedef _Traits traits_type; 73 typedef typename traits_type::int_type int_type; 74 typedef typename traits_type::pos_type pos_type; 75 typedef typename traits_type::off_type off_type; 76 77 typedef basic_streambuf<char_type, traits_type> __streambuf_type; 78 typedef basic_filebuf<char_type, traits_type> __filebuf_type; 79 typedef __basic_file<char> __file_type; 80 typedef typename traits_type::state_type __state_type; 81 typedef codecvt<char_type, char, __state_type> __codecvt_type; 82 83 friend class ios_base; // For sync_with_stdio. 84 85 protected: 86 // Data Members: 87 // MT lock inherited from libio or other low-level io library. 88 __c_lock _M_lock; 89 90 // External buffer. 91 __file_type _M_file; 92 93 /// Place to stash in || out || in | out settings for current filebuf. 94 ios_base::openmode _M_mode; 95 96 // Beginning state type for codecvt. 97 __state_type _M_state_beg; 98 99 // During output, the state that corresponds to pptr(), 100 // during input, the state that corresponds to egptr() and 101 // _M_ext_next. 102 __state_type _M_state_cur; 103 104 // Not used for output. During input, the state that corresponds 105 // to eback() and _M_ext_buf. 106 __state_type _M_state_last; 107 108 /// Pointer to the beginning of internal buffer. 109 char_type* _M_buf; 110 111 /** 112 * Actual size of internal buffer. This number is equal to the size 113 * of the put area + 1 position, reserved for the overflow char of 114 * a full area. 115 */ 116 size_t _M_buf_size; 117 118 // Set iff _M_buf is allocated memory from _M_allocate_internal_buffer. 119 bool _M_buf_allocated; 120 121 /** 122 * _M_reading == false && _M_writing == false for @b uncommitted mode; 123 * _M_reading == true for @b read mode; 124 * _M_writing == true for @b write mode; 125 * 126 * NB: _M_reading == true && _M_writing == true is unused. 127 */ 128 bool _M_reading; 129 bool _M_writing; 130 131 //@{ 132 /** 133 * Necessary bits for putback buffer management. 134 * 135 * @note pbacks of over one character are not currently supported. 136 */ 137 char_type _M_pback; 138 char_type* _M_pback_cur_save; 139 char_type* _M_pback_end_save; 140 bool _M_pback_init; 141 //@} 142 143 // Cached codecvt facet. 144 const __codecvt_type* _M_codecvt; 145 146 /** 147 * Buffer for external characters. Used for input when 148 * codecvt::always_noconv() == false. When valid, this corresponds 149 * to eback(). 150 */ 151 char* _M_ext_buf; 152 153 /** 154 * Size of buffer held by _M_ext_buf. 155 */ 156 streamsize _M_ext_buf_size; 157 158 /** 159 * Pointers into the buffer held by _M_ext_buf that delimit a 160 * subsequence of bytes that have been read but not yet converted. 161 * When valid, _M_ext_next corresponds to egptr(). 162 */ 163 const char* _M_ext_next; 164 char* _M_ext_end; 165 166 /** 167 * Initializes pback buffers, and moves normal buffers to safety. 168 * Assumptions: 169 * _M_in_cur has already been moved back 170 */ 171 void 172 _M_create_pback() 173 { 174 if (!_M_pback_init) 175 { 176 _M_pback_cur_save = this->gptr(); 177 _M_pback_end_save = this->egptr(); 178 this->setg(&_M_pback, &_M_pback, &_M_pback + 1); 179 _M_pback_init = true; 180 } 181 } 182 183 /** 184 * Deactivates pback buffer contents, and restores normal buffer. 185 * Assumptions: 186 * The pback buffer has only moved forward. 187 */ 188 void 189 _M_destroy_pback() throw() 190 { 191 if (_M_pback_init) 192 { 193 // Length _M_in_cur moved in the pback buffer. 194 _M_pback_cur_save += this->gptr() != this->eback(); 195 this->setg(_M_buf, _M_pback_cur_save, _M_pback_end_save); 196 _M_pback_init = false; 197 } 198 } 199 200 public: 201 // Constructors/destructor: 202 /** 203 * @brief Does not open any files. 204 * 205 * The default constructor initializes the parent class using its 206 * own default ctor. 207 */ 208 basic_filebuf(); 209 210 /** 211 * @brief The destructor closes the file first. 212 */ 213 virtual 214 ~basic_filebuf() 215 { this->close(); } 216 217 // Members: 218 /** 219 * @brief Returns true if the external file is open. 220 */ 221 bool 222 is_open() const throw() 223 { return _M_file.is_open(); } 224 225 /** 226 * @brief Opens an external file. 227 * @param s The name of the file. 228 * @param mode The open mode flags. 229 * @return @c this on success, NULL on failure 230 * 231 * If a file is already open, this function immediately fails. 232 * Otherwise it tries to open the file named @a s using the flags 233 * given in @a mode. 234 * 235 * Table 92, adapted here, gives the relation between openmode 236 * combinations and the equivalent fopen() flags. 237 * (NB: lines app, in|out|app, in|app, binary|app, binary|in|out|app, 238 * and binary|in|app per DR 596) 239 * +---------------------------------------------------------+ 240 * | ios_base Flag combination stdio equivalent | 241 * |binary in out trunc app | 242 * +---------------------------------------------------------+ 243 * | + w | 244 * | + + a | 245 * | + a | 246 * | + + w | 247 * | + r | 248 * | + + r+ | 249 * | + + + w+ | 250 * | + + + a+ | 251 * | + + a+ | 252 * +---------------------------------------------------------+ 253 * | + + wb | 254 * | + + + ab | 255 * | + + ab | 256 * | + + + wb | 257 * | + + rb | 258 * | + + + r+b | 259 * | + + + + w+b | 260 * | + + + + a+b | 261 * | + + + a+b | 262 * +---------------------------------------------------------+ 263 */ 264 __filebuf_type* 265 open(const char* __s, ios_base::openmode __mode); 266 267#ifdef __GXX_EXPERIMENTAL_CXX0X__ 268 /** 269 * @brief Opens an external file. 270 * @param s The name of the file. 271 * @param mode The open mode flags. 272 * @return @c this on success, NULL on failure 273 */ 274 __filebuf_type* 275 open(const std::string& __s, ios_base::openmode __mode) 276 { return open(__s.c_str(), __mode); } 277#endif 278 279 /** 280 * @brief Closes the currently associated file. 281 * @return @c this on success, NULL on failure 282 * 283 * If no file is currently open, this function immediately fails. 284 * 285 * If a <em>put buffer area</em> exists, @c overflow(eof) is 286 * called to flush all the characters. The file is then 287 * closed. 288 * 289 * If any operations fail, this function also fails. 290 */ 291 __filebuf_type* 292 close(); 293 294 protected: 295 void 296 _M_allocate_internal_buffer(); 297 298 void 299 _M_destroy_internal_buffer() throw(); 300 301 // [27.8.1.4] overridden virtual functions 302 virtual streamsize 303 showmanyc(); 304 305 // Stroustrup, 1998, p. 628 306 // underflow() and uflow() functions are called to get the next 307 // character from the real input source when the buffer is empty. 308 // Buffered input uses underflow() 309 310 virtual int_type 311 underflow(); 312 313 virtual int_type 314 pbackfail(int_type __c = _Traits::eof()); 315 316 // Stroustrup, 1998, p 648 317 // The overflow() function is called to transfer characters to the 318 // real output destination when the buffer is full. A call to 319 // overflow(c) outputs the contents of the buffer plus the 320 // character c. 321 // 27.5.2.4.5 322 // Consume some sequence of the characters in the pending sequence. 323 virtual int_type 324 overflow(int_type __c = _Traits::eof()); 325 326 // Convert internal byte sequence to external, char-based 327 // sequence via codecvt. 328 bool 329 _M_convert_to_external(char_type*, streamsize); 330 331 /** 332 * @brief Manipulates the buffer. 333 * @param s Pointer to a buffer area. 334 * @param n Size of @a s. 335 * @return @c this 336 * 337 * If no file has been opened, and both @a s and @a n are zero, then 338 * the stream becomes unbuffered. Otherwise, @c s is used as a 339 * buffer; see 340 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html 341 * for more. 342 */ 343 virtual __streambuf_type* 344 setbuf(char_type* __s, streamsize __n); 345 346 virtual pos_type 347 seekoff(off_type __off, ios_base::seekdir __way, 348 ios_base::openmode __mode = ios_base::in | ios_base::out); 349 350 virtual pos_type 351 seekpos(pos_type __pos, 352 ios_base::openmode __mode = ios_base::in | ios_base::out); 353 354 // Common code for seekoff and seekpos 355 pos_type 356 _M_seek(off_type __off, ios_base::seekdir __way, __state_type __state); 357 358 virtual int 359 sync(); 360 361 virtual void 362 imbue(const locale& __loc); 363 364 virtual streamsize 365 xsgetn(char_type* __s, streamsize __n); 366 367 virtual streamsize 368 xsputn(const char_type* __s, streamsize __n); 369 370 // Flushes output buffer, then writes unshift sequence. 371 bool 372 _M_terminate_output(); 373 374 /** 375 * This function sets the pointers of the internal buffer, both get 376 * and put areas. Typically: 377 * 378 * __off == egptr() - eback() upon underflow/uflow (@b read mode); 379 * __off == 0 upon overflow (@b write mode); 380 * __off == -1 upon open, setbuf, seekoff/pos (@b uncommitted mode). 381 * 382 * NB: epptr() - pbase() == _M_buf_size - 1, since _M_buf_size 383 * reflects the actual allocated memory and the last cell is reserved 384 * for the overflow char of a full put area. 385 */ 386 void 387 _M_set_buffer(streamsize __off) 388 { 389 const bool __testin = _M_mode & ios_base::in; 390 const bool __testout = _M_mode & ios_base::out; 391 392 if (__testin && __off > 0) 393 this->setg(_M_buf, _M_buf, _M_buf + __off); 394 else 395 this->setg(_M_buf, _M_buf, _M_buf); 396 397 if (__testout && __off == 0 && _M_buf_size > 1 ) 398 this->setp(_M_buf, _M_buf + _M_buf_size - 1); 399 else 400 this->setp(NULL, NULL); 401 } 402 }; 403 404 // [27.8.1.5] Template class basic_ifstream 405 /** 406 * @brief Controlling input for files. 407 * @ingroup io 408 * 409 * This class supports reading from named files, using the inherited 410 * functions from std::basic_istream. To control the associated 411 * sequence, an instance of std::basic_filebuf is used, which this page 412 * refers to as @c sb. 413 */ 414 template<typename _CharT, typename _Traits> 415 class basic_ifstream : public basic_istream<_CharT, _Traits> 416 { 417 public: 418 // Types: 419 typedef _CharT char_type; 420 typedef _Traits traits_type; 421 typedef typename traits_type::int_type int_type; 422 typedef typename traits_type::pos_type pos_type; 423 typedef typename traits_type::off_type off_type; 424 425 // Non-standard types: 426 typedef basic_filebuf<char_type, traits_type> __filebuf_type; 427 typedef basic_istream<char_type, traits_type> __istream_type; 428 429 private: 430 __filebuf_type _M_filebuf; 431 432 public: 433 // Constructors/Destructors: 434 /** 435 * @brief Default constructor. 436 * 437 * Initializes @c sb using its default constructor, and passes 438 * @c &sb to the base class initializer. Does not open any files 439 * (you haven't given it a filename to open). 440 */ 441 basic_ifstream() : __istream_type(), _M_filebuf() 442 { this->init(&_M_filebuf); } 443 444 /** 445 * @brief Create an input file stream. 446 * @param s Null terminated string specifying the filename. 447 * @param mode Open file in specified mode (see std::ios_base). 448 * 449 * @c ios_base::in is automatically included in @a mode. 450 * 451 * Tip: When using std::string to hold the filename, you must use 452 * .c_str() before passing it to this constructor. 453 */ 454 explicit 455 basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in) 456 : __istream_type(), _M_filebuf() 457 { 458 this->init(&_M_filebuf); 459 this->open(__s, __mode); 460 } 461 462#ifdef __GXX_EXPERIMENTAL_CXX0X__ 463 /** 464 * @brief Create an input file stream. 465 * @param s std::string specifying the filename. 466 * @param mode Open file in specified mode (see std::ios_base). 467 * 468 * @c ios_base::in is automatically included in @a mode. 469 */ 470 explicit 471 basic_ifstream(const std::string& __s, 472 ios_base::openmode __mode = ios_base::in) 473 : __istream_type(), _M_filebuf() 474 { 475 this->init(&_M_filebuf); 476 this->open(__s, __mode); 477 } 478#endif 479 480 /** 481 * @brief The destructor does nothing. 482 * 483 * The file is closed by the filebuf object, not the formatting 484 * stream. 485 */ 486 ~basic_ifstream() 487 { } 488 489 // Members: 490 /** 491 * @brief Accessing the underlying buffer. 492 * @return The current basic_filebuf buffer. 493 * 494 * This hides both signatures of std::basic_ios::rdbuf(). 495 */ 496 __filebuf_type* 497 rdbuf() const 498 { return const_cast<__filebuf_type*>(&_M_filebuf); } 499 500 /** 501 * @brief Wrapper to test for an open file. 502 * @return @c rdbuf()->is_open() 503 */ 504 bool 505 is_open() 506 { return _M_filebuf.is_open(); } 507 508 // _GLIBCXX_RESOLVE_LIB_DEFECTS 509 // 365. Lack of const-qualification in clause 27 510 bool 511 is_open() const 512 { return _M_filebuf.is_open(); } 513 514 /** 515 * @brief Opens an external file. 516 * @param s The name of the file. 517 * @param mode The open mode flags. 518 * 519 * Calls @c std::basic_filebuf::open(s,mode|in). If that function 520 * fails, @c failbit is set in the stream's error state. 521 * 522 * Tip: When using std::string to hold the filename, you must use 523 * .c_str() before passing it to this constructor. 524 */ 525 void 526 open(const char* __s, ios_base::openmode __mode = ios_base::in) 527 { 528 if (!_M_filebuf.open(__s, __mode | ios_base::in)) 529 this->setstate(ios_base::failbit); 530 else 531 // _GLIBCXX_RESOLVE_LIB_DEFECTS 532 // 409. Closing an fstream should clear error state 533 this->clear(); 534 } 535 536#ifdef __GXX_EXPERIMENTAL_CXX0X__ 537 /** 538 * @brief Opens an external file. 539 * @param s The name of the file. 540 * @param mode The open mode flags. 541 * 542 * Calls @c std::basic_filebuf::open(s,mode|in). If that function 543 * fails, @c failbit is set in the stream's error state. 544 */ 545 void 546 open(const std::string& __s, ios_base::openmode __mode = ios_base::in) 547 { 548 if (!_M_filebuf.open(__s, __mode | ios_base::in)) 549 this->setstate(ios_base::failbit); 550 else 551 // _GLIBCXX_RESOLVE_LIB_DEFECTS 552 // 409. Closing an fstream should clear error state 553 this->clear(); 554 } 555#endif 556 557 /** 558 * @brief Close the file. 559 * 560 * Calls @c std::basic_filebuf::close(). If that function 561 * fails, @c failbit is set in the stream's error state. 562 */ 563 void 564 close() 565 { 566 if (!_M_filebuf.close()) 567 this->setstate(ios_base::failbit); 568 } 569 }; 570 571 572 // [27.8.1.8] Template class basic_ofstream 573 /** 574 * @brief Controlling output for files. 575 * @ingroup io 576 * 577 * This class supports reading from named files, using the inherited 578 * functions from std::basic_ostream. To control the associated 579 * sequence, an instance of std::basic_filebuf is used, which this page 580 * refers to as @c sb. 581 */ 582 template<typename _CharT, typename _Traits> 583 class basic_ofstream : public basic_ostream<_CharT,_Traits> 584 { 585 public: 586 // Types: 587 typedef _CharT char_type; 588 typedef _Traits traits_type; 589 typedef typename traits_type::int_type int_type; 590 typedef typename traits_type::pos_type pos_type; 591 typedef typename traits_type::off_type off_type; 592 593 // Non-standard types: 594 typedef basic_filebuf<char_type, traits_type> __filebuf_type; 595 typedef basic_ostream<char_type, traits_type> __ostream_type; 596 597 private: 598 __filebuf_type _M_filebuf; 599 600 public: 601 // Constructors: 602 /** 603 * @brief Default constructor. 604 * 605 * Initializes @c sb using its default constructor, and passes 606 * @c &sb to the base class initializer. Does not open any files 607 * (you haven't given it a filename to open). 608 */ 609 basic_ofstream(): __ostream_type(), _M_filebuf() 610 { this->init(&_M_filebuf); } 611 612 /** 613 * @brief Create an output file stream. 614 * @param s Null terminated string specifying the filename. 615 * @param mode Open file in specified mode (see std::ios_base). 616 * 617 * @c ios_base::out|ios_base::trunc is automatically included in 618 * @a mode. 619 * 620 * Tip: When using std::string to hold the filename, you must use 621 * .c_str() before passing it to this constructor. 622 */ 623 explicit 624 basic_ofstream(const char* __s, 625 ios_base::openmode __mode = ios_base::out|ios_base::trunc) 626 : __ostream_type(), _M_filebuf() 627 { 628 this->init(&_M_filebuf); 629 this->open(__s, __mode); 630 } 631 632#ifdef __GXX_EXPERIMENTAL_CXX0X__ 633 /** 634 * @brief Create an output file stream. 635 * @param s std::string specifying the filename. 636 * @param mode Open file in specified mode (see std::ios_base). 637 * 638 * @c ios_base::out|ios_base::trunc is automatically included in 639 * @a mode. 640 */ 641 explicit 642 basic_ofstream(const std::string& __s, 643 ios_base::openmode __mode = ios_base::out|ios_base::trunc) 644 : __ostream_type(), _M_filebuf() 645 { 646 this->init(&_M_filebuf); 647 this->open(__s, __mode); 648 } 649#endif 650 651 /** 652 * @brief The destructor does nothing. 653 * 654 * The file is closed by the filebuf object, not the formatting 655 * stream. 656 */ 657 ~basic_ofstream() 658 { } 659 660 // Members: 661 /** 662 * @brief Accessing the underlying buffer. 663 * @return The current basic_filebuf buffer. 664 * 665 * This hides both signatures of std::basic_ios::rdbuf(). 666 */ 667 __filebuf_type* 668 rdbuf() const 669 { return const_cast<__filebuf_type*>(&_M_filebuf); } 670 671 /** 672 * @brief Wrapper to test for an open file. 673 * @return @c rdbuf()->is_open() 674 */ 675 bool 676 is_open() 677 { return _M_filebuf.is_open(); } 678 679 // _GLIBCXX_RESOLVE_LIB_DEFECTS 680 // 365. Lack of const-qualification in clause 27 681 bool 682 is_open() const 683 { return _M_filebuf.is_open(); } 684 685 /** 686 * @brief Opens an external file. 687 * @param s The name of the file. 688 * @param mode The open mode flags. 689 * 690 * Calls @c std::basic_filebuf::open(s,mode|out|trunc). If that 691 * function fails, @c failbit is set in the stream's error state. 692 * 693 * Tip: When using std::string to hold the filename, you must use 694 * .c_str() before passing it to this constructor. 695 */ 696 void 697 open(const char* __s, 698 ios_base::openmode __mode = ios_base::out | ios_base::trunc) 699 { 700 if (!_M_filebuf.open(__s, __mode | ios_base::out)) 701 this->setstate(ios_base::failbit); 702 else 703 // _GLIBCXX_RESOLVE_LIB_DEFECTS 704 // 409. Closing an fstream should clear error state 705 this->clear(); 706 } 707 708#ifdef __GXX_EXPERIMENTAL_CXX0X__ 709 /** 710 * @brief Opens an external file. 711 * @param s The name of the file. 712 * @param mode The open mode flags. 713 * 714 * Calls @c std::basic_filebuf::open(s,mode|out|trunc). If that 715 * function fails, @c failbit is set in the stream's error state. 716 */ 717 void 718 open(const std::string& __s, 719 ios_base::openmode __mode = ios_base::out | ios_base::trunc) 720 { 721 if (!_M_filebuf.open(__s, __mode | ios_base::out)) 722 this->setstate(ios_base::failbit); 723 else 724 // _GLIBCXX_RESOLVE_LIB_DEFECTS 725 // 409. Closing an fstream should clear error state 726 this->clear(); 727 } 728#endif 729 730 /** 731 * @brief Close the file. 732 * 733 * Calls @c std::basic_filebuf::close(). If that function 734 * fails, @c failbit is set in the stream's error state. 735 */ 736 void 737 close() 738 { 739 if (!_M_filebuf.close()) 740 this->setstate(ios_base::failbit); 741 } 742 }; 743 744 745 // [27.8.1.11] Template class basic_fstream 746 /** 747 * @brief Controlling input and output for files. 748 * @ingroup io 749 * 750 * This class supports reading from and writing to named files, using 751 * the inherited functions from std::basic_iostream. To control the 752 * associated sequence, an instance of std::basic_filebuf is used, which 753 * this page refers to as @c sb. 754 */ 755 template<typename _CharT, typename _Traits> 756 class basic_fstream : public basic_iostream<_CharT, _Traits> 757 { 758 public: 759 // Types: 760 typedef _CharT char_type; 761 typedef _Traits traits_type; 762 typedef typename traits_type::int_type int_type; 763 typedef typename traits_type::pos_type pos_type; 764 typedef typename traits_type::off_type off_type; 765 766 // Non-standard types: 767 typedef basic_filebuf<char_type, traits_type> __filebuf_type; 768 typedef basic_ios<char_type, traits_type> __ios_type; 769 typedef basic_iostream<char_type, traits_type> __iostream_type; 770 771 private: 772 __filebuf_type _M_filebuf; 773 774 public: 775 // Constructors/destructor: 776 /** 777 * @brief Default constructor. 778 * 779 * Initializes @c sb using its default constructor, and passes 780 * @c &sb to the base class initializer. Does not open any files 781 * (you haven't given it a filename to open). 782 */ 783 basic_fstream() 784 : __iostream_type(), _M_filebuf() 785 { this->init(&_M_filebuf); } 786 787 /** 788 * @brief Create an input/output file stream. 789 * @param s Null terminated string specifying the filename. 790 * @param mode Open file in specified mode (see std::ios_base). 791 * 792 * Tip: When using std::string to hold the filename, you must use 793 * .c_str() before passing it to this constructor. 794 */ 795 explicit 796 basic_fstream(const char* __s, 797 ios_base::openmode __mode = ios_base::in | ios_base::out) 798 : __iostream_type(NULL), _M_filebuf() 799 { 800 this->init(&_M_filebuf); 801 this->open(__s, __mode); 802 } 803 804#ifdef __GXX_EXPERIMENTAL_CXX0X__ 805 /** 806 * @brief Create an input/output file stream. 807 * @param s Null terminated string specifying the filename. 808 * @param mode Open file in specified mode (see std::ios_base). 809 */ 810 explicit 811 basic_fstream(const std::string& __s, 812 ios_base::openmode __mode = ios_base::in | ios_base::out) 813 : __iostream_type(NULL), _M_filebuf() 814 { 815 this->init(&_M_filebuf); 816 this->open(__s, __mode); 817 } 818#endif 819 820 /** 821 * @brief The destructor does nothing. 822 * 823 * The file is closed by the filebuf object, not the formatting 824 * stream. 825 */ 826 ~basic_fstream() 827 { } 828 829 // Members: 830 /** 831 * @brief Accessing the underlying buffer. 832 * @return The current basic_filebuf buffer. 833 * 834 * This hides both signatures of std::basic_ios::rdbuf(). 835 */ 836 __filebuf_type* 837 rdbuf() const 838 { return const_cast<__filebuf_type*>(&_M_filebuf); } 839 840 /** 841 * @brief Wrapper to test for an open file. 842 * @return @c rdbuf()->is_open() 843 */ 844 bool 845 is_open() 846 { return _M_filebuf.is_open(); } 847 848 // _GLIBCXX_RESOLVE_LIB_DEFECTS 849 // 365. Lack of const-qualification in clause 27 850 bool 851 is_open() const 852 { return _M_filebuf.is_open(); } 853 854 /** 855 * @brief Opens an external file. 856 * @param s The name of the file. 857 * @param mode The open mode flags. 858 * 859 * Calls @c std::basic_filebuf::open(s,mode). If that 860 * function fails, @c failbit is set in the stream's error state. 861 * 862 * Tip: When using std::string to hold the filename, you must use 863 * .c_str() before passing it to this constructor. 864 */ 865 void 866 open(const char* __s, 867 ios_base::openmode __mode = ios_base::in | ios_base::out) 868 { 869 if (!_M_filebuf.open(__s, __mode)) 870 this->setstate(ios_base::failbit); 871 else 872 // _GLIBCXX_RESOLVE_LIB_DEFECTS 873 // 409. Closing an fstream should clear error state 874 this->clear(); 875 } 876 877#ifdef __GXX_EXPERIMENTAL_CXX0X__ 878 /** 879 * @brief Opens an external file. 880 * @param s The name of the file. 881 * @param mode The open mode flags. 882 * 883 * Calls @c std::basic_filebuf::open(s,mode). If that 884 * function fails, @c failbit is set in the stream's error state. 885 */ 886 void 887 open(const std::string& __s, 888 ios_base::openmode __mode = ios_base::in | ios_base::out) 889 { 890 if (!_M_filebuf.open(__s, __mode)) 891 this->setstate(ios_base::failbit); 892 else 893 // _GLIBCXX_RESOLVE_LIB_DEFECTS 894 // 409. Closing an fstream should clear error state 895 this->clear(); 896 } 897#endif 898 899 /** 900 * @brief Close the file. 901 * 902 * Calls @c std::basic_filebuf::close(). If that function 903 * fails, @c failbit is set in the stream's error state. 904 */ 905 void 906 close() 907 { 908 if (!_M_filebuf.close()) 909 this->setstate(ios_base::failbit); 910 } 911 }; 912 913_GLIBCXX_END_NAMESPACE 914 915#ifndef _GLIBCXX_EXPORT_TEMPLATE 916# include <bits/fstream.tcc> 917#endif 918 919#endif /* _GLIBCXX_FSTREAM */ 920