1// File based streams -*- C++ -*-
2
3// Copyright (C) 1997-2022 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 include/fstream
26 * This is a Standard C++ Library header.
27 */
28
29//
30// ISO C++ 14882: 27.8 File-based streams
31//
32
33#ifndef _GLIBCXX_FSTREAM
34#define _GLIBCXX_FSTREAM 1
35
36#pragma GCC system_header
37
38#include <istream>
39#include <ostream>
40#include <bits/codecvt.h>
41#include <cstdio> // For BUFSIZ
42#include <bits/basic_file.h> // For __basic_file, __c_lock
43#if __cplusplus >= 201103L
44#include <string> // For std::string overloads.
45#endif
46
47// This can be overridden by the target's os_defines.h
48#ifndef _GLIBCXX_BUFSIZ
49# define _GLIBCXX_BUFSIZ BUFSIZ
50#endif
51
52namespace std _GLIBCXX_VISIBILITY(default)
53{
54_GLIBCXX_BEGIN_NAMESPACE_VERSION
55
56#if __cplusplus >= 201703L
57 // Enable if _Path is a filesystem::path or experimental::filesystem::path
58 template<typename _Path, typename _Result = _Path, typename _Path2
59 = decltype(std::declval<_Path&>().make_preferred().filename())>
60 using _If_fs_path = enable_if_t<is_same_v<_Path, _Path2>, _Result>;
61#endif // C++17
62
63
64 // [27.8.1.1] template class basic_filebuf
65 /**
66 * @brief The actual work of input and output (for files).
67 * @ingroup io
68 *
69 * @tparam _CharT Type of character stream.
70 * @tparam _Traits Traits for character type, defaults to
71 * char_traits<_CharT>.
72 *
73 * This class associates both its input and output sequence with an
74 * external disk file, and maintains a joint file position for both
75 * sequences. Many of its semantics are described in terms of similar
76 * behavior in the Standard C Library's @c FILE streams.
77 *
78 * Requirements on traits_type, specific to this class:
79 * - traits_type::pos_type must be fpos<traits_type::state_type>
80 * - traits_type::off_type must be streamoff
81 * - traits_type::state_type must be Assignable and DefaultConstructible,
82 * - traits_type::state_type() must be the initial state for codecvt.
83 */
84 template<typename _CharT, typename _Traits>
85 class basic_filebuf : public basic_streambuf<_CharT, _Traits>
86 {
87#if __cplusplus >= 201103L
88 template<typename _Tp>
89 using __chk_state = __and_<is_copy_assignable<_Tp>,
90 is_copy_constructible<_Tp>,
91 is_default_constructible<_Tp>>;
92
93 static_assert(__chk_state<typename _Traits::state_type>::value,
94 "state_type must be CopyAssignable, CopyConstructible"
95 " and DefaultConstructible");
96
97 static_assert(is_same<typename _Traits::pos_type,
98 fpos<typename _Traits::state_type>>::value,
99 "pos_type must be fpos<state_type>");
100#endif
101 public:
102 // Types:
103 typedef _CharT char_type;
104 typedef _Traits traits_type;
105 typedef typename traits_type::int_type int_type;
106 typedef typename traits_type::pos_type pos_type;
107 typedef typename traits_type::off_type off_type;
108
109 typedef basic_streambuf<char_type, traits_type> __streambuf_type;
110 typedef basic_filebuf<char_type, traits_type> __filebuf_type;
111 typedef __basic_file<char> __file_type;
112 typedef typename traits_type::state_type __state_type;
113 typedef codecvt<char_type, char, __state_type> __codecvt_type;
114
115 friend class ios_base; // For sync_with_stdio.
116
117 protected:
118 // Data Members:
119 // MT lock inherited from libio or other low-level io library.
120 __c_lock _M_lock;
121
122 // External buffer.
123 __file_type _M_file;
124
125 /// Place to stash in || out || in | out settings for current filebuf.
126 ios_base::openmode _M_mode;
127
128 // Beginning state type for codecvt.
129 __state_type _M_state_beg;
130
131 // During output, the state that corresponds to pptr(),
132 // during input, the state that corresponds to egptr() and
133 // _M_ext_next.
134 __state_type _M_state_cur;
135
136 // Not used for output. During input, the state that corresponds
137 // to eback() and _M_ext_buf.
138 __state_type _M_state_last;
139
140 /// Pointer to the beginning of internal buffer.
141 char_type* _M_buf;
142
143 /**
144 * Actual size of internal buffer. This number is equal to the size
145 * of the put area + 1 position, reserved for the overflow char of
146 * a full area.
147 */
148 size_t _M_buf_size;
149
150 // Set iff _M_buf is allocated memory from _M_allocate_internal_buffer.
151 bool _M_buf_allocated;
152
153 /**
154 * _M_reading == false && _M_writing == false for @b uncommitted mode;
155 * _M_reading == true for @b read mode;
156 * _M_writing == true for @b write mode;
157 *
158 * NB: _M_reading == true && _M_writing == true is unused.
159 */
160 bool _M_reading;
161 bool _M_writing;
162
163 ///@{
164 /**
165 * Necessary bits for putback buffer management.
166 *
167 * @note pbacks of over one character are not currently supported.
168 */
169 char_type _M_pback;
170 char_type* _M_pback_cur_save;
171 char_type* _M_pback_end_save;
172 bool _M_pback_init;
173 ///@}
174
175 // Cached codecvt facet.
176 const __codecvt_type* _M_codecvt;
177
178 /**
179 * Buffer for external characters. Used for input when
180 * codecvt::always_noconv() == false. When valid, this corresponds
181 * to eback().
182 */
183 char* _M_ext_buf;
184
185 /**
186 * Size of buffer held by _M_ext_buf.
187 */
188 streamsize _M_ext_buf_size;
189
190 /**
191 * Pointers into the buffer held by _M_ext_buf that delimit a
192 * subsequence of bytes that have been read but not yet converted.
193 * When valid, _M_ext_next corresponds to egptr().
194 */
195 const char* _M_ext_next;
196 char* _M_ext_end;
197
198 /**
199 * Initializes pback buffers, and moves normal buffers to safety.
200 * Assumptions:
201 * _M_in_cur has already been moved back
202 */
203 void
204 _M_create_pback()
205 {
206 if (!_M_pback_init)
207 {
208 _M_pback_cur_save = this->gptr();
209 _M_pback_end_save = this->egptr();
210 this->setg(&_M_pback, &_M_pback, &_M_pback + 1);
211 _M_pback_init = true;
212 }
213 }
214
215 /**
216 * Deactivates pback buffer contents, and restores normal buffer.
217 * Assumptions:
218 * The pback buffer has only moved forward.
219 */
220 void
221 _M_destroy_pback() throw()
222 {
223 if (_M_pback_init)
224 {
225 // Length _M_in_cur moved in the pback buffer.
226 _M_pback_cur_save += this->gptr() != this->eback();
227 this->setg(_M_buf, _M_pback_cur_save, _M_pback_end_save);
228 _M_pback_init = false;
229 }
230 }
231
232 public:
233 // Constructors/destructor:
234 /**
235 * @brief Does not open any files.
236 *
237 * The default constructor initializes the parent class using its
238 * own default ctor.
239 */
240 basic_filebuf();
241
242#if __cplusplus >= 201103L
243 basic_filebuf(const basic_filebuf&) = delete;
244 basic_filebuf(basic_filebuf&&);
245#endif
246
247 /**
248 * @brief The destructor closes the file first.
249 */
250 virtual
251 ~basic_filebuf()
252 {
253 __try
254 { this->close(); }
255 __catch(...)
256 { }
257 }
258
259#if __cplusplus >= 201103L
260 basic_filebuf& operator=(const basic_filebuf&) = delete;
261 basic_filebuf& operator=(basic_filebuf&&);
262 void swap(basic_filebuf&);
263#endif
264
265 // Members:
266 /**
267 * @brief Returns true if the external file is open.
268 */
269 bool
270 is_open() const throw()
271 { return _M_file.is_open(); }
272
273 /**
274 * @brief Opens an external file.
275 * @param __s The name of the file.
276 * @param __mode The open mode flags.
277 * @return @c this on success, NULL on failure
278 *
279 * If a file is already open, this function immediately fails.
280 * Otherwise it tries to open the file named @a __s using the flags
281 * given in @a __mode.
282 *
283 * Table 92, adapted here, gives the relation between openmode
284 * combinations and the equivalent @c fopen() flags.
285 * (NB: lines app, in|out|app, in|app, binary|app, binary|in|out|app,
286 * and binary|in|app per DR 596)
287 * <pre>
288 * +---------------------------------------------------------+
289 * | ios_base Flag combination stdio equivalent |
290 * |binary in out trunc app |
291 * +---------------------------------------------------------+
292 * | + w |
293 * | + + a |
294 * | + a |
295 * | + + w |
296 * | + r |
297 * | + + r+ |
298 * | + + + w+ |
299 * | + + + a+ |
300 * | + + a+ |
301 * +---------------------------------------------------------+
302 * | + + wb |
303 * | + + + ab |
304 * | + + ab |
305 * | + + + wb |
306 * | + + rb |
307 * | + + + r+b |
308 * | + + + + w+b |
309 * | + + + + a+b |
310 * | + + + a+b |
311 * +---------------------------------------------------------+
312 * </pre>
313 */
314 __filebuf_type*
315 open(const char* __s, ios_base::openmode __mode);
316
317#if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T
318 /**
319 * @brief Opens an external file.
320 * @param __s The name of the file, as a wide character string.
321 * @param __mode The open mode flags.
322 * @return @c this on success, NULL on failure
323 */
324 __filebuf_type*
325 open(const wchar_t* __s, ios_base::openmode __mode);
326#endif
327
328#if __cplusplus >= 201103L
329 /**
330 * @brief Opens an external file.
331 * @param __s The name of the file.
332 * @param __mode The open mode flags.
333 * @return @c this on success, NULL on failure
334 */
335 __filebuf_type*
336 open(const std::string& __s, ios_base::openmode __mode)
337 { return open(__s.c_str(), __mode); }
338
339#if __cplusplus >= 201703L
340 /**
341 * @brief Opens an external file.
342 * @param __s The name of the file, as a filesystem::path.
343 * @param __mode The open mode flags.
344 * @return @c this on success, NULL on failure
345 */
346 template<typename _Path>
347 _If_fs_path<_Path, __filebuf_type*>
348 open(const _Path& __s, ios_base::openmode __mode)
349 { return open(__s.c_str(), __mode); }
350#endif // C++17
351#endif // C++11
352
353 /**
354 * @brief Closes the currently associated file.
355 * @return @c this on success, NULL on failure
356 *
357 * If no file is currently open, this function immediately fails.
358 *
359 * If a <em>put buffer area</em> exists, @c overflow(eof) is
360 * called to flush all the characters. The file is then
361 * closed.
362 *
363 * If any operations fail, this function also fails.
364 */
365 __filebuf_type*
366 close();
367
368 protected:
369 void
370 _M_allocate_internal_buffer();
371
372 void
373 _M_destroy_internal_buffer() throw();
374
375 // [27.8.1.4] overridden virtual functions
376 virtual streamsize
377 showmanyc();
378
379 // Stroustrup, 1998, p. 628
380 // underflow() and uflow() functions are called to get the next
381 // character from the real input source when the buffer is empty.
382 // Buffered input uses underflow()
383
384 virtual int_type
385 underflow();
386
387 virtual int_type
388 pbackfail(int_type __c = _Traits::eof());
389
390 // Stroustrup, 1998, p 648
391 // The overflow() function is called to transfer characters to the
392 // real output destination when the buffer is full. A call to
393 // overflow(c) outputs the contents of the buffer plus the
394 // character c.
395 // 27.5.2.4.5
396 // Consume some sequence of the characters in the pending sequence.
397 virtual int_type
398 overflow(int_type __c = _Traits::eof());
399
400 // Convert internal byte sequence to external, char-based
401 // sequence via codecvt.
402 bool
403 _M_convert_to_external(char_type*, streamsize);
404
405 /**
406 * @brief Manipulates the buffer.
407 * @param __s Pointer to a buffer area.
408 * @param __n Size of @a __s.
409 * @return @c this
410 *
411 * If no file has been opened, and both @a __s and @a __n are zero, then
412 * the stream becomes unbuffered. Otherwise, @c __s is used as a
413 * buffer; see
414 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering
415 * for more.
416 */
417 virtual __streambuf_type*
418 setbuf(char_type* __s, streamsize __n);
419
420 virtual pos_type
421 seekoff(off_type __off, ios_base::seekdir __way,
422 ios_base::openmode __mode = ios_base::in | ios_base::out);
423
424 virtual pos_type
425 seekpos(pos_type __pos,
426 ios_base::openmode __mode = ios_base::in | ios_base::out);
427
428 // Common code for seekoff, seekpos, and overflow
429 pos_type
430 _M_seek(off_type __off, ios_base::seekdir __way, __state_type __state);
431
432 int
433 _M_get_ext_pos(__state_type &__state);
434
435 virtual int
436 sync();
437
438 virtual void
439 imbue(const locale& __loc);
440
441 virtual streamsize
442 xsgetn(char_type* __s, streamsize __n);
443
444 virtual streamsize
445 xsputn(const char_type* __s, streamsize __n);
446
447 // Flushes output buffer, then writes unshift sequence.
448 bool
449 _M_terminate_output();
450
451 /**
452 * This function sets the pointers of the internal buffer, both get
453 * and put areas. Typically:
454 *
455 * __off == egptr() - eback() upon underflow/uflow (@b read mode);
456 * __off == 0 upon overflow (@b write mode);
457 * __off == -1 upon open, setbuf, seekoff/pos (@b uncommitted mode).
458 *
459 * NB: epptr() - pbase() == _M_buf_size - 1, since _M_buf_size
460 * reflects the actual allocated memory and the last cell is reserved
461 * for the overflow char of a full put area.
462 */
463 void
464 _M_set_buffer(streamsize __off)
465 {
466 const bool __testin = _M_mode & ios_base::in;
467 const bool __testout = (_M_mode & ios_base::out
468 || _M_mode & ios_base::app);
469
470 if (__testin && __off > 0)
471 this->setg(_M_buf, _M_buf, _M_buf + __off);
472 else
473 this->setg(_M_buf, _M_buf, _M_buf);
474
475 if (__testout && __off == 0 && _M_buf_size > 1 )
476 this->setp(_M_buf, _M_buf + _M_buf_size - 1);
477 else
478 this->setp(0, 0);
479 }
480 };
481
482 // [27.8.1.5] Template class basic_ifstream
483 /**
484 * @brief Controlling input for files.
485 * @ingroup io
486 *
487 * @tparam _CharT Type of character stream.
488 * @tparam _Traits Traits for character type, defaults to
489 * char_traits<_CharT>.
490 *
491 * This class supports reading from named files, using the inherited
492 * functions from std::basic_istream. To control the associated
493 * sequence, an instance of std::basic_filebuf is used, which this page
494 * refers to as @c sb.
495 */
496 template<typename _CharT, typename _Traits>
497 class basic_ifstream : public basic_istream<_CharT, _Traits>
498 {
499 public:
500 // Types:
501 typedef _CharT char_type;
502 typedef _Traits traits_type;
503 typedef typename traits_type::int_type int_type;
504 typedef typename traits_type::pos_type pos_type;
505 typedef typename traits_type::off_type off_type;
506
507 // Non-standard types:
508 typedef basic_filebuf<char_type, traits_type> __filebuf_type;
509 typedef basic_istream<char_type, traits_type> __istream_type;
510
511 private:
512 __filebuf_type _M_filebuf;
513
514 public:
515 // Constructors/Destructors:
516 /**
517 * @brief Default constructor.
518 *
519 * Initializes @c sb using its default constructor, and passes
520 * @c &sb to the base class initializer. Does not open any files
521 * (you haven't given it a filename to open).
522 */
523 basic_ifstream() : __istream_type(), _M_filebuf()
524 { this->init(&_M_filebuf); }
525
526 /**
527 * @brief Create an input file stream.
528 * @param __s Null terminated string specifying the filename.
529 * @param __mode Open file in specified mode (see std::ios_base).
530 *
531 * @c ios_base::in is automatically included in @a __mode.
532 */
533 explicit
534 basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in)
535 : __istream_type(), _M_filebuf()
536 {
537 this->init(&_M_filebuf);
538 this->open(__s, __mode);
539 }
540
541#if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T
542 /**
543 * @param Create an input file stream.
544 * @param __s Wide string specifying the filename.
545 * @param __mode Open file in specified mode (see std::ios_base).
546 *
547 * @c ios_base::in is automatically included in @a __mode.
548 */
549 basic_ifstream(const wchar_t* __s,
550 ios_base::openmode __mode = ios_base::in)
551 : __istream_type(), _M_filebuf()
552 {
553 this->init(&_M_filebuf);
554 this->open(__s, __mode);
555 }
556#endif
557
558#if __cplusplus >= 201103L
559 /**
560 * @brief Create an input file stream.
561 * @param __s std::string specifying the filename.
562 * @param __mode Open file in specified mode (see std::ios_base).
563 *
564 * @c ios_base::in is automatically included in @a __mode.
565 */
566 explicit
567 basic_ifstream(const std::string& __s,
568 ios_base::openmode __mode = ios_base::in)
569 : __istream_type(), _M_filebuf()
570 {
571 this->init(&_M_filebuf);
572 this->open(__s, __mode);
573 }
574
575#if __cplusplus >= 201703L
576 /**
577 * @brief Create an input file stream.
578 * @param __s filesystem::path specifying the filename.
579 * @param __mode Open file in specified mode (see std::ios_base).
580 *
581 * @c ios_base::in is automatically included in @a __mode.
582 */
583 template<typename _Path, typename _Require = _If_fs_path<_Path>>
584 basic_ifstream(const _Path& __s,
585 ios_base::openmode __mode = ios_base::in)
586 : basic_ifstream(__s.c_str(), __mode)
587 { }
588#endif // C++17
589
590 basic_ifstream(const basic_ifstream&) = delete;
591
592 basic_ifstream(basic_ifstream&& __rhs)
593 : __istream_type(std::move(__rhs)),
594 _M_filebuf(std::move(__rhs._M_filebuf))
595 { __istream_type::set_rdbuf(&_M_filebuf); }
596#endif // C++11
597
598 /**
599 * @brief The destructor does nothing.
600 *
601 * The file is closed by the filebuf object, not the formatting
602 * stream.
603 */
604 ~basic_ifstream()
605 { }
606
607#if __cplusplus >= 201103L
608 // 27.8.3.2 Assign and swap:
609
610 basic_ifstream&
611 operator=(const basic_ifstream&) = delete;
612
613 basic_ifstream&
614 operator=(basic_ifstream&& __rhs)
615 {
616 __istream_type::operator=(std::move(__rhs));
617 _M_filebuf = std::move(__rhs._M_filebuf);
618 return *this;
619 }
620
621 void
622 swap(basic_ifstream& __rhs)
623 {
624 __istream_type::swap(__rhs);
625 _M_filebuf.swap(__rhs._M_filebuf);
626 }
627#endif
628
629 // Members:
630 /**
631 * @brief Accessing the underlying buffer.
632 * @return The current basic_filebuf buffer.
633 *
634 * This hides both signatures of std::basic_ios::rdbuf().
635 */
636 __filebuf_type*
637 rdbuf() const
638 { return const_cast<__filebuf_type*>(&_M_filebuf); }
639
640 /**
641 * @brief Wrapper to test for an open file.
642 * @return @c rdbuf()->is_open()
643 */
644 bool
645 is_open()
646 { return _M_filebuf.is_open(); }
647
648 // _GLIBCXX_RESOLVE_LIB_DEFECTS
649 // 365. Lack of const-qualification in clause 27
650 bool
651 is_open() const
652 { return _M_filebuf.is_open(); }
653
654 /**
655 * @brief Opens an external file.
656 * @param __s The name of the file.
657 * @param __mode The open mode flags.
658 *
659 * Calls @c std::basic_filebuf::open(s,__mode|in). If that function
660 * fails, @c failbit is set in the stream's error state.
661 */
662 void
663 open(const char* __s, ios_base::openmode __mode = ios_base::in)
664 {
665 if (!_M_filebuf.open(__s, __mode | ios_base::in))
666 this->setstate(ios_base::failbit);
667 else
668 // _GLIBCXX_RESOLVE_LIB_DEFECTS
669 // 409. Closing an fstream should clear error state
670 this->clear();
671 }
672
673#if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T
674 /**
675 * @brief Opens an external file.
676 * @param __s The name of the file, as a wide character string.
677 * @param __mode The open mode flags.
678 *
679 * Calls @c std::basic_filebuf::open(__s,__mode|in). If that function
680 * fails, @c failbit is set in the stream's error state.
681 */
682 void
683 open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in)
684 {
685 if (!_M_filebuf.open(__s, __mode | ios_base::in))
686 this->setstate(ios_base::failbit);
687 else
688 this->clear();
689 }
690#endif
691
692#if __cplusplus >= 201103L
693 /**
694 * @brief Opens an external file.
695 * @param __s The name of the file.
696 * @param __mode The open mode flags.
697 *
698 * Calls @c std::basic_filebuf::open(__s,__mode|in). If that function
699 * fails, @c failbit is set in the stream's error state.
700 */
701 void
702 open(const std::string& __s, ios_base::openmode __mode = ios_base::in)
703 {
704 if (!_M_filebuf.open(__s, __mode | ios_base::in))
705 this->setstate(ios_base::failbit);
706 else
707 // _GLIBCXX_RESOLVE_LIB_DEFECTS
708 // 409. Closing an fstream should clear error state
709 this->clear();
710 }
711
712#if __cplusplus >= 201703L
713 /**
714 * @brief Opens an external file.
715 * @param __s The name of the file, as a filesystem::path.
716 * @param __mode The open mode flags.
717 *
718 * Calls @c std::basic_filebuf::open(__s,__mode|in). If that function
719 * fails, @c failbit is set in the stream's error state.
720 */
721 template<typename _Path>
722 _If_fs_path<_Path, void>
723 open(const _Path& __s, ios_base::openmode __mode = ios_base::in)
724 { open(__s.c_str(), __mode); }
725#endif // C++17
726#endif // C++11
727
728 /**
729 * @brief Close the file.
730 *
731 * Calls @c std::basic_filebuf::close(). If that function
732 * fails, @c failbit is set in the stream's error state.
733 */
734 void
735 close()
736 {
737 if (!_M_filebuf.close())
738 this->setstate(ios_base::failbit);
739 }
740 };
741
742
743 // [27.8.1.8] Template class basic_ofstream
744 /**
745 * @brief Controlling output for files.
746 * @ingroup io
747 *
748 * @tparam _CharT Type of character stream.
749 * @tparam _Traits Traits for character type, defaults to
750 * char_traits<_CharT>.
751 *
752 * This class supports reading from named files, using the inherited
753 * functions from std::basic_ostream. To control the associated
754 * sequence, an instance of std::basic_filebuf is used, which this page
755 * refers to as @c sb.
756 */
757 template<typename _CharT, typename _Traits>
758 class basic_ofstream : public basic_ostream<_CharT,_Traits>
759 {
760 public:
761 // Types:
762 typedef _CharT char_type;
763 typedef _Traits traits_type;
764 typedef typename traits_type::int_type int_type;
765 typedef typename traits_type::pos_type pos_type;
766 typedef typename traits_type::off_type off_type;
767
768 // Non-standard types:
769 typedef basic_filebuf<char_type, traits_type> __filebuf_type;
770 typedef basic_ostream<char_type, traits_type> __ostream_type;
771
772 private:
773 __filebuf_type _M_filebuf;
774
775 public:
776 // Constructors:
777 /**
778 * @brief Default constructor.
779 *
780 * Initializes @c sb using its default constructor, and passes
781 * @c &sb to the base class initializer. Does not open any files
782 * (you haven't given it a filename to open).
783 */
784 basic_ofstream(): __ostream_type(), _M_filebuf()
785 { this->init(&_M_filebuf); }
786
787 /**
788 * @brief Create an 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 * @c ios_base::out is automatically included in @a __mode.
793 */
794 explicit
795 basic_ofstream(const char* __s,
796 ios_base::openmode __mode = ios_base::out)
797 : __ostream_type(), _M_filebuf()
798 {
799 this->init(&_M_filebuf);
800 this->open(__s, __mode);
801 }
802
803#if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T
804 /**
805 * @param Create an output file stream.
806 * @param __s Wide string specifying the filename.
807 * @param __mode Open file in specified mode (see std::ios_base).
808 *
809 * @c ios_base::out | @c ios_base::trunc is automatically included in
810 * @a __mode.
811 */
812 basic_ofstream(const wchar_t* __s,
813 ios_base::openmode __mode = ios_base::out|ios_base::trunc)
814 : __ostream_type(), _M_filebuf()
815 {
816 this->init(&_M_filebuf);
817 this->open(__s, __mode);
818 }
819#endif
820
821#if __cplusplus >= 201103L
822 /**
823 * @brief Create an output file stream.
824 * @param __s std::string specifying the filename.
825 * @param __mode Open file in specified mode (see std::ios_base).
826 *
827 * @c ios_base::out is automatically included in @a __mode.
828 */
829 explicit
830 basic_ofstream(const std::string& __s,
831 ios_base::openmode __mode = ios_base::out)
832 : __ostream_type(), _M_filebuf()
833 {
834 this->init(&_M_filebuf);
835 this->open(__s, __mode);
836 }
837
838#if __cplusplus >= 201703L
839 /**
840 * @brief Create an output file stream.
841 * @param __s filesystem::path specifying the filename.
842 * @param __mode Open file in specified mode (see std::ios_base).
843 *
844 * @c ios_base::out is automatically included in @a __mode.
845 */
846 template<typename _Path, typename _Require = _If_fs_path<_Path>>
847 basic_ofstream(const _Path& __s,
848 ios_base::openmode __mode = ios_base::out)
849 : basic_ofstream(__s.c_str(), __mode)
850 { }
851#endif // C++17
852
853 basic_ofstream(const basic_ofstream&) = delete;
854
855 basic_ofstream(basic_ofstream&& __rhs)
856 : __ostream_type(std::move(__rhs)),
857 _M_filebuf(std::move(__rhs._M_filebuf))
858 { __ostream_type::set_rdbuf(&_M_filebuf); }
859#endif
860
861 /**
862 * @brief The destructor does nothing.
863 *
864 * The file is closed by the filebuf object, not the formatting
865 * stream.
866 */
867 ~basic_ofstream()
868 { }
869
870#if __cplusplus >= 201103L
871 // 27.8.3.2 Assign and swap:
872
873 basic_ofstream&
874 operator=(const basic_ofstream&) = delete;
875
876 basic_ofstream&
877 operator=(basic_ofstream&& __rhs)
878 {
879 __ostream_type::operator=(std::move(__rhs));
880 _M_filebuf = std::move(__rhs._M_filebuf);
881 return *this;
882 }
883
884 void
885 swap(basic_ofstream& __rhs)
886 {
887 __ostream_type::swap(__rhs);
888 _M_filebuf.swap(__rhs._M_filebuf);
889 }
890#endif
891
892 // Members:
893 /**
894 * @brief Accessing the underlying buffer.
895 * @return The current basic_filebuf buffer.
896 *
897 * This hides both signatures of std::basic_ios::rdbuf().
898 */
899 __filebuf_type*
900 rdbuf() const
901 { return const_cast<__filebuf_type*>(&_M_filebuf); }
902
903 /**
904 * @brief Wrapper to test for an open file.
905 * @return @c rdbuf()->is_open()
906 */
907 bool
908 is_open()
909 { return _M_filebuf.is_open(); }
910
911 // _GLIBCXX_RESOLVE_LIB_DEFECTS
912 // 365. Lack of const-qualification in clause 27
913 bool
914 is_open() const
915 { return _M_filebuf.is_open(); }
916
917 /**
918 * @brief Opens an external file.
919 * @param __s The name of the file.
920 * @param __mode The open mode flags.
921 *
922 * Calls @c std::basic_filebuf::open(__s,__mode|out). If that
923 * function fails, @c failbit is set in the stream's error state.
924 */
925 void
926 open(const char* __s, ios_base::openmode __mode = ios_base::out)
927 {
928 if (!_M_filebuf.open(__s, __mode | ios_base::out))
929 this->setstate(ios_base::failbit);
930 else
931 // _GLIBCXX_RESOLVE_LIB_DEFECTS
932 // 409. Closing an fstream should clear error state
933 this->clear();
934 }
935
936#if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T
937 /**
938 * @brief Opens an external file.
939 * @param __s The name of the file.
940 * @param __mode The open mode flags.
941 *
942 * Calls @c std::basic_filebuf::open(__s,__mode|out). If that
943 * function fails, @c failbit is set in the stream's error state.
944 */
945 void
946 open(const wchar_t* __s, ios_base::openmode __mode = ios_base::out)
947 {
948 if (!_M_filebuf.open(__s, __mode | ios_base::out))
949 this->setstate(ios_base::failbit);
950 else
951 this->clear();
952 }
953#endif
954
955#if __cplusplus >= 201103L
956 /**
957 * @brief Opens an external file.
958 * @param __s The name of the file.
959 * @param __mode The open mode flags.
960 *
961 * Calls @c std::basic_filebuf::open(s,mode|out). If that
962 * function fails, @c failbit is set in the stream's error state.
963 */
964 void
965 open(const std::string& __s, ios_base::openmode __mode = ios_base::out)
966 {
967 if (!_M_filebuf.open(__s, __mode | ios_base::out))
968 this->setstate(ios_base::failbit);
969 else
970 // _GLIBCXX_RESOLVE_LIB_DEFECTS
971 // 409. Closing an fstream should clear error state
972 this->clear();
973 }
974
975#if __cplusplus >= 201703L
976 /**
977 * @brief Opens an external file.
978 * @param __s The name of the file, as a filesystem::path.
979 * @param __mode The open mode flags.
980 *
981 * Calls @c std::basic_filebuf::open(__s,__mode|out). If that
982 * function fails, @c failbit is set in the stream's error state.
983 */
984 template<typename _Path>
985 _If_fs_path<_Path, void>
986 open(const _Path& __s, ios_base::openmode __mode = ios_base::out)
987 { open(__s.c_str(), __mode); }
988#endif // C++17
989#endif // C++11
990
991 /**
992 * @brief Close the file.
993 *
994 * Calls @c std::basic_filebuf::close(). If that function
995 * fails, @c failbit is set in the stream's error state.
996 */
997 void
998 close()
999 {
1000 if (!_M_filebuf.close())
1001 this->setstate(ios_base::failbit);
1002 }
1003 };
1004
1005
1006 // [27.8.1.11] Template class basic_fstream
1007 /**
1008 * @brief Controlling input and output for files.
1009 * @ingroup io
1010 *
1011 * @tparam _CharT Type of character stream.
1012 * @tparam _Traits Traits for character type, defaults to
1013 * char_traits<_CharT>.
1014 *
1015 * This class supports reading from and writing to named files, using
1016 * the inherited functions from std::basic_iostream. To control the
1017 * associated sequence, an instance of std::basic_filebuf is used, which
1018 * this page refers to as @c sb.
1019 */
1020 template<typename _CharT, typename _Traits>
1021 class basic_fstream : public basic_iostream<_CharT, _Traits>
1022 {
1023 public:
1024 // Types:
1025 typedef _CharT char_type;
1026 typedef _Traits traits_type;
1027 typedef typename traits_type::int_type int_type;
1028 typedef typename traits_type::pos_type pos_type;
1029 typedef typename traits_type::off_type off_type;
1030
1031 // Non-standard types:
1032 typedef basic_filebuf<char_type, traits_type> __filebuf_type;
1033 typedef basic_ios<char_type, traits_type> __ios_type;
1034 typedef basic_iostream<char_type, traits_type> __iostream_type;
1035
1036 private:
1037 __filebuf_type _M_filebuf;
1038
1039 public:
1040 // Constructors/destructor:
1041 /**
1042 * @brief Default constructor.
1043 *
1044 * Initializes @c sb using its default constructor, and passes
1045 * @c &sb to the base class initializer. Does not open any files
1046 * (you haven't given it a filename to open).
1047 */
1048 basic_fstream()
1049 : __iostream_type(), _M_filebuf()
1050 { this->init(&_M_filebuf); }
1051
1052 /**
1053 * @brief Create an input/output file stream.
1054 * @param __s Null terminated string specifying the filename.
1055 * @param __mode Open file in specified mode (see std::ios_base).
1056 */
1057 explicit
1058 basic_fstream(const char* __s,
1059 ios_base::openmode __mode = ios_base::in | ios_base::out)
1060 : __iostream_type(0), _M_filebuf()
1061 {
1062 this->init(&_M_filebuf);
1063 this->open(__s, __mode);
1064 }
1065
1066#if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T
1067 /**
1068 * @param Create an input/output file stream.
1069 * @param __s Wide string specifying the filename.
1070 * @param __mode Open file in specified mode (see std::ios_base).
1071 */
1072 basic_fstream(const wchar_t* __s,
1073 ios_base::openmode __mode = ios_base::in | ios_base::out)
1074 : __iostream_type(0), _M_filebuf()
1075 {
1076 this->init(&_M_filebuf);
1077 this->open(__s, __mode);
1078 }
1079#endif
1080
1081#if __cplusplus >= 201103L
1082 /**
1083 * @brief Create an input/output file stream.
1084 * @param __s Null terminated string specifying the filename.
1085 * @param __mode Open file in specified mode (see std::ios_base).
1086 */
1087 explicit
1088 basic_fstream(const std::string& __s,
1089 ios_base::openmode __mode = ios_base::in | ios_base::out)
1090 : __iostream_type(0), _M_filebuf()
1091 {
1092 this->init(&_M_filebuf);
1093 this->open(__s, __mode);
1094 }
1095
1096#if __cplusplus >= 201703L
1097 /**
1098 * @brief Create an input/output file stream.
1099 * @param __s filesystem::path specifying the filename.
1100 * @param __mode Open file in specified mode (see std::ios_base).
1101 */
1102 template<typename _Path, typename _Require = _If_fs_path<_Path>>
1103 basic_fstream(const _Path& __s,
1104 ios_base::openmode __mode = ios_base::in | ios_base::out)
1105 : basic_fstream(__s.c_str(), __mode)
1106 { }
1107#endif // C++17
1108
1109 basic_fstream(const basic_fstream&) = delete;
1110
1111 basic_fstream(basic_fstream&& __rhs)
1112 : __iostream_type(std::move(__rhs)),
1113 _M_filebuf(std::move(__rhs._M_filebuf))
1114 { __iostream_type::set_rdbuf(&_M_filebuf); }
1115#endif
1116
1117 /**
1118 * @brief The destructor does nothing.
1119 *
1120 * The file is closed by the filebuf object, not the formatting
1121 * stream.
1122 */
1123 ~basic_fstream()
1124 { }
1125
1126#if __cplusplus >= 201103L
1127 // 27.8.3.2 Assign and swap:
1128
1129 basic_fstream&
1130 operator=(const basic_fstream&) = delete;
1131
1132 basic_fstream&
1133 operator=(basic_fstream&& __rhs)
1134 {
1135 __iostream_type::operator=(std::move(__rhs));
1136 _M_filebuf = std::move(__rhs._M_filebuf);
1137 return *this;
1138 }
1139
1140 void
1141 swap(basic_fstream& __rhs)
1142 {
1143 __iostream_type::swap(__rhs);
1144 _M_filebuf.swap(__rhs._M_filebuf);
1145 }
1146#endif
1147
1148 // Members:
1149 /**
1150 * @brief Accessing the underlying buffer.
1151 * @return The current basic_filebuf buffer.
1152 *
1153 * This hides both signatures of std::basic_ios::rdbuf().
1154 */
1155 __filebuf_type*
1156 rdbuf() const
1157 { return const_cast<__filebuf_type*>(&_M_filebuf); }
1158
1159 /**
1160 * @brief Wrapper to test for an open file.
1161 * @return @c rdbuf()->is_open()
1162 */
1163 bool
1164 is_open()
1165 { return _M_filebuf.is_open(); }
1166
1167 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1168 // 365. Lack of const-qualification in clause 27
1169 bool
1170 is_open() const
1171 { return _M_filebuf.is_open(); }
1172
1173 /**
1174 * @brief Opens an external file.
1175 * @param __s The name of the file.
1176 * @param __mode The open mode flags.
1177 *
1178 * Calls @c std::basic_filebuf::open(__s,__mode). If that
1179 * function fails, @c failbit is set in the stream's error state.
1180 */
1181 void
1182 open(const char* __s,
1183 ios_base::openmode __mode = ios_base::in | ios_base::out)
1184 {
1185 if (!_M_filebuf.open(__s, __mode))
1186 this->setstate(ios_base::failbit);
1187 else
1188 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1189 // 409. Closing an fstream should clear error state
1190 this->clear();
1191 }
1192
1193#if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T
1194 /**
1195 * @brief Opens an external file.
1196 * @param __s The name of the file.
1197 * @param __mode The open mode flags.
1198 *
1199 * Calls @c std::basic_filebuf::open(__s,__mode). If that
1200 * function fails, @c failbit is set in the stream's error state.
1201 */
1202 void
1203 open(const wchar_t* __s,
1204 ios_base::openmode __mode = ios_base::in | ios_base::out)
1205 {
1206 if (!_M_filebuf.open(__s, __mode))
1207 this->setstate(ios_base::failbit);
1208 else
1209 this->clear();
1210 }
1211#endif
1212
1213#if __cplusplus >= 201103L
1214 /**
1215 * @brief Opens an external file.
1216 * @param __s The name of the file.
1217 * @param __mode The open mode flags.
1218 *
1219 * Calls @c std::basic_filebuf::open(__s,__mode). If that
1220 * function fails, @c failbit is set in the stream's error state.
1221 */
1222 void
1223 open(const std::string& __s,
1224 ios_base::openmode __mode = ios_base::in | ios_base::out)
1225 {
1226 if (!_M_filebuf.open(__s, __mode))
1227 this->setstate(ios_base::failbit);
1228 else
1229 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1230 // 409. Closing an fstream should clear error state
1231 this->clear();
1232 }
1233
1234#if __cplusplus >= 201703L
1235 /**
1236 * @brief Opens an external file.
1237 * @param __s The name of the file, as a filesystem::path.
1238 * @param __mode The open mode flags.
1239 *
1240 * Calls @c std::basic_filebuf::open(__s,__mode). If that
1241 * function fails, @c failbit is set in the stream's error state.
1242 */
1243 template<typename _Path>
1244 _If_fs_path<_Path, void>
1245 open(const _Path& __s,
1246 ios_base::openmode __mode = ios_base::in | ios_base::out)
1247 { open(__s.c_str(), __mode); }
1248#endif // C++17
1249#endif // C++11
1250
1251 /**
1252 * @brief Close the file.
1253 *
1254 * Calls @c std::basic_filebuf::close(). If that function
1255 * fails, @c failbit is set in the stream's error state.
1256 */
1257 void
1258 close()
1259 {
1260 if (!_M_filebuf.close())
1261 this->setstate(ios_base::failbit);
1262 }
1263 };
1264
1265#if __cplusplus >= 201103L
1266 /// Swap specialization for filebufs.
1267 template <class _CharT, class _Traits>
1268 inline void
1269 swap(basic_filebuf<_CharT, _Traits>& __x,
1270 basic_filebuf<_CharT, _Traits>& __y)
1271 { __x.swap(__y); }
1272
1273 /// Swap specialization for ifstreams.
1274 template <class _CharT, class _Traits>
1275 inline void
1276 swap(basic_ifstream<_CharT, _Traits>& __x,
1277 basic_ifstream<_CharT, _Traits>& __y)
1278 { __x.swap(__y); }
1279
1280 /// Swap specialization for ofstreams.
1281 template <class _CharT, class _Traits>
1282 inline void
1283 swap(basic_ofstream<_CharT, _Traits>& __x,
1284 basic_ofstream<_CharT, _Traits>& __y)
1285 { __x.swap(__y); }
1286
1287 /// Swap specialization for fstreams.
1288 template <class _CharT, class _Traits>
1289 inline void
1290 swap(basic_fstream<_CharT, _Traits>& __x,
1291 basic_fstream<_CharT, _Traits>& __y)
1292 { __x.swap(__y); }
1293#endif
1294
1295_GLIBCXX_END_NAMESPACE_VERSION
1296} // namespace
1297
1298#include <bits/fstream.tcc>
1299
1300#endif /* _GLIBCXX_FSTREAM */
1301