1 // File based streams -*- C++ -*-
3 // Copyright (C) 1997-2017 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file include/fstream
26 * This is a Standard C++ Library header.
30 // ISO C++ 14882: 27.8 File-based streams
33 #ifndef _GLIBCXX_FSTREAM
34 #define _GLIBCXX_FSTREAM 1
36 #pragma GCC system_header
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.
47 namespace std _GLIBCXX_VISIBILITY(default)
49 _GLIBCXX_BEGIN_NAMESPACE_VERSION
51 // [27.8.1.1] template class basic_filebuf
53 * @brief The actual work of input and output (for files).
56 * @tparam _CharT Type of character stream.
57 * @tparam _Traits Traits for character type, defaults to
58 * char_traits<_CharT>.
60 * This class associates both its input and output sequence with an
61 * external disk file, and maintains a joint file position for both
62 * sequences. Many of its semantics are described in terms of similar
63 * behavior in the Standard C Library's @c FILE streams.
65 * Requirements on traits_type, specific to this class:
66 * - traits_type::pos_type must be fpos<traits_type::state_type>
67 * - traits_type::off_type must be streamoff
68 * - traits_type::state_type must be Assignable and DefaultConstructible,
69 * - traits_type::state_type() must be the initial state for codecvt.
71 template<typename _CharT, typename _Traits>
72 class basic_filebuf : public basic_streambuf<_CharT, _Traits>
74 #if __cplusplus >= 201103L
75 template<typename _Tp>
76 using __chk_state = __and_<is_copy_assignable<_Tp>,
77 is_copy_constructible<_Tp>,
78 is_default_constructible<_Tp>>;
80 static_assert(__chk_state<typename _Traits::state_type>::value,
81 "state_type must be CopyAssignable, CopyConstructible"
82 " and DefaultConstructible");
84 static_assert(is_same<typename _Traits::pos_type,
85 fpos<typename _Traits::state_type>>::value,
86 "pos_type must be fpos<state_type>");
90 typedef _CharT char_type;
91 typedef _Traits traits_type;
92 typedef typename traits_type::int_type int_type;
93 typedef typename traits_type::pos_type pos_type;
94 typedef typename traits_type::off_type off_type;
96 typedef basic_streambuf<char_type, traits_type> __streambuf_type;
97 typedef basic_filebuf<char_type, traits_type> __filebuf_type;
98 typedef __basic_file<char> __file_type;
99 typedef typename traits_type::state_type __state_type;
100 typedef codecvt<char_type, char, __state_type> __codecvt_type;
102 friend class ios_base; // For sync_with_stdio.
106 // MT lock inherited from libio or other low-level io library.
112 /// Place to stash in || out || in | out settings for current filebuf.
113 ios_base::openmode _M_mode;
115 // Beginning state type for codecvt.
116 __state_type _M_state_beg;
118 // During output, the state that corresponds to pptr(),
119 // during input, the state that corresponds to egptr() and
121 __state_type _M_state_cur;
123 // Not used for output. During input, the state that corresponds
124 // to eback() and _M_ext_buf.
125 __state_type _M_state_last;
127 /// Pointer to the beginning of internal buffer.
131 * Actual size of internal buffer. This number is equal to the size
132 * of the put area + 1 position, reserved for the overflow char of
137 // Set iff _M_buf is allocated memory from _M_allocate_internal_buffer.
138 bool _M_buf_allocated;
141 * _M_reading == false && _M_writing == false for @b uncommitted mode;
142 * _M_reading == true for @b read mode;
143 * _M_writing == true for @b write mode;
145 * NB: _M_reading == true && _M_writing == true is unused.
152 * Necessary bits for putback buffer management.
154 * @note pbacks of over one character are not currently supported.
157 char_type* _M_pback_cur_save;
158 char_type* _M_pback_end_save;
162 // Cached codecvt facet.
163 const __codecvt_type* _M_codecvt;
166 * Buffer for external characters. Used for input when
167 * codecvt::always_noconv() == false. When valid, this corresponds
173 * Size of buffer held by _M_ext_buf.
175 streamsize _M_ext_buf_size;
178 * Pointers into the buffer held by _M_ext_buf that delimit a
179 * subsequence of bytes that have been read but not yet converted.
180 * When valid, _M_ext_next corresponds to egptr().
182 const char* _M_ext_next;
186 * Initializes pback buffers, and moves normal buffers to safety.
188 * _M_in_cur has already been moved back
195 _M_pback_cur_save = this->gptr();
196 _M_pback_end_save = this->egptr();
197 this->setg(&_M_pback, &_M_pback, &_M_pback + 1);
198 _M_pback_init = true;
203 * Deactivates pback buffer contents, and restores normal buffer.
205 * The pback buffer has only moved forward.
208 _M_destroy_pback() throw()
212 // Length _M_in_cur moved in the pback buffer.
213 _M_pback_cur_save += this->gptr() != this->eback();
214 this->setg(_M_buf, _M_pback_cur_save, _M_pback_end_save);
215 _M_pback_init = false;
219 #if __cplusplus >= 201703L
220 template<typename _Path, typename _Result = _Path, typename _Path2
221 = decltype(std::declval<_Path&>().make_preferred().native())>
222 using _If_path = enable_if_t<is_same_v<_Path, _Path2>, _Result>;
226 // Constructors/destructor:
228 * @brief Does not open any files.
230 * The default constructor initializes the parent class using its
235 #if __cplusplus >= 201103L
236 basic_filebuf(const basic_filebuf&) = delete;
237 basic_filebuf(basic_filebuf&&);
241 * @brief The destructor closes the file first.
247 #if __cplusplus >= 201103L
248 basic_filebuf& operator=(const basic_filebuf&) = delete;
249 basic_filebuf& operator=(basic_filebuf&&);
250 void swap(basic_filebuf&);
255 * @brief Returns true if the external file is open.
258 is_open() const throw()
259 { return _M_file.is_open(); }
262 * @brief Opens an external file.
263 * @param __s The name of the file.
264 * @param __mode The open mode flags.
265 * @return @c this on success, NULL on failure
267 * If a file is already open, this function immediately fails.
268 * Otherwise it tries to open the file named @a __s using the flags
269 * given in @a __mode.
271 * Table 92, adapted here, gives the relation between openmode
272 * combinations and the equivalent @c fopen() flags.
273 * (NB: lines app, in|out|app, in|app, binary|app, binary|in|out|app,
274 * and binary|in|app per DR 596)
276 * +---------------------------------------------------------+
277 * | ios_base Flag combination stdio equivalent |
278 * |binary in out trunc app |
279 * +---------------------------------------------------------+
289 * +---------------------------------------------------------+
299 * +---------------------------------------------------------+
303 open(const char* __s, ios_base::openmode __mode);
305 #if __cplusplus >= 201103L
307 * @brief Opens an external file.
308 * @param __s The name of the file.
309 * @param __mode The open mode flags.
310 * @return @c this on success, NULL on failure
313 open(const std::string& __s, ios_base::openmode __mode)
314 { return open(__s.c_str(), __mode); }
316 #if __cplusplus >= 201703L
318 * @brief Opens an external file.
319 * @param __s The name of the file, as a filesystem::path.
320 * @param __mode The open mode flags.
321 * @return @c this on success, NULL on failure
323 template<typename _Path>
324 _If_path<_Path, __filebuf_type*>
325 open(const _Path& __s, ios_base::openmode __mode)
326 { return open(__s.c_str(), __mode); }
331 * @brief Closes the currently associated file.
332 * @return @c this on success, NULL on failure
334 * If no file is currently open, this function immediately fails.
336 * If a <em>put buffer area</em> exists, @c overflow(eof) is
337 * called to flush all the characters. The file is then
340 * If any operations fail, this function also fails.
347 _M_allocate_internal_buffer();
350 _M_destroy_internal_buffer() throw();
352 // [27.8.1.4] overridden virtual functions
356 // Stroustrup, 1998, p. 628
357 // underflow() and uflow() functions are called to get the next
358 // character from the real input source when the buffer is empty.
359 // Buffered input uses underflow()
365 pbackfail(int_type __c = _Traits::eof());
367 // Stroustrup, 1998, p 648
368 // The overflow() function is called to transfer characters to the
369 // real output destination when the buffer is full. A call to
370 // overflow(c) outputs the contents of the buffer plus the
373 // Consume some sequence of the characters in the pending sequence.
375 overflow(int_type __c = _Traits::eof());
377 // Convert internal byte sequence to external, char-based
378 // sequence via codecvt.
380 _M_convert_to_external(char_type*, streamsize);
383 * @brief Manipulates the buffer.
384 * @param __s Pointer to a buffer area.
385 * @param __n Size of @a __s.
388 * If no file has been opened, and both @a __s and @a __n are zero, then
389 * the stream becomes unbuffered. Otherwise, @c __s is used as a
391 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering
394 virtual __streambuf_type*
395 setbuf(char_type* __s, streamsize __n);
398 seekoff(off_type __off, ios_base::seekdir __way,
399 ios_base::openmode __mode = ios_base::in | ios_base::out);
402 seekpos(pos_type __pos,
403 ios_base::openmode __mode = ios_base::in | ios_base::out);
405 // Common code for seekoff, seekpos, and overflow
407 _M_seek(off_type __off, ios_base::seekdir __way, __state_type __state);
410 _M_get_ext_pos(__state_type &__state);
416 imbue(const locale& __loc);
419 xsgetn(char_type* __s, streamsize __n);
422 xsputn(const char_type* __s, streamsize __n);
424 // Flushes output buffer, then writes unshift sequence.
426 _M_terminate_output();
429 * This function sets the pointers of the internal buffer, both get
430 * and put areas. Typically:
432 * __off == egptr() - eback() upon underflow/uflow (@b read mode);
433 * __off == 0 upon overflow (@b write mode);
434 * __off == -1 upon open, setbuf, seekoff/pos (@b uncommitted mode).
436 * NB: epptr() - pbase() == _M_buf_size - 1, since _M_buf_size
437 * reflects the actual allocated memory and the last cell is reserved
438 * for the overflow char of a full put area.
441 _M_set_buffer(streamsize __off)
443 const bool __testin = _M_mode & ios_base::in;
444 const bool __testout = (_M_mode & ios_base::out
445 || _M_mode & ios_base::app);
447 if (__testin && __off > 0)
448 this->setg(_M_buf, _M_buf, _M_buf + __off);
450 this->setg(_M_buf, _M_buf, _M_buf);
452 if (__testout && __off == 0 && _M_buf_size > 1 )
453 this->setp(_M_buf, _M_buf + _M_buf_size - 1);
459 // [27.8.1.5] Template class basic_ifstream
461 * @brief Controlling input for files.
464 * @tparam _CharT Type of character stream.
465 * @tparam _Traits Traits for character type, defaults to
466 * char_traits<_CharT>.
468 * This class supports reading from named files, using the inherited
469 * functions from std::basic_istream. To control the associated
470 * sequence, an instance of std::basic_filebuf is used, which this page
471 * refers to as @c sb.
473 template<typename _CharT, typename _Traits>
474 class basic_ifstream : public basic_istream<_CharT, _Traits>
478 typedef _CharT char_type;
479 typedef _Traits traits_type;
480 typedef typename traits_type::int_type int_type;
481 typedef typename traits_type::pos_type pos_type;
482 typedef typename traits_type::off_type off_type;
484 // Non-standard types:
485 typedef basic_filebuf<char_type, traits_type> __filebuf_type;
486 typedef basic_istream<char_type, traits_type> __istream_type;
489 __filebuf_type _M_filebuf;
492 // Constructors/Destructors:
494 * @brief Default constructor.
496 * Initializes @c sb using its default constructor, and passes
497 * @c &sb to the base class initializer. Does not open any files
498 * (you haven't given it a filename to open).
500 basic_ifstream() : __istream_type(), _M_filebuf()
501 { this->init(&_M_filebuf); }
504 * @brief Create an input file stream.
505 * @param __s Null terminated string specifying the filename.
506 * @param __mode Open file in specified mode (see std::ios_base).
508 * @c ios_base::in is automatically included in @a __mode.
511 basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in)
512 : __istream_type(), _M_filebuf()
514 this->init(&_M_filebuf);
515 this->open(__s, __mode);
518 #if __cplusplus >= 201103L
520 * @brief Create an input file stream.
521 * @param __s std::string specifying the filename.
522 * @param __mode Open file in specified mode (see std::ios_base).
524 * @c ios_base::in is automatically included in @a __mode.
527 basic_ifstream(const std::string& __s,
528 ios_base::openmode __mode = ios_base::in)
529 : __istream_type(), _M_filebuf()
531 this->init(&_M_filebuf);
532 this->open(__s, __mode);
535 #if __cplusplus >= 201703L
537 * @param Create an input file stream.
538 * @param __s filesystem::path specifying the filename.
539 * @param __mode Open file in specified mode (see std::ios_base).
541 * @c ios_base::in is automatically included in @a __mode.
543 template<typename _Path, typename = _Require<
544 is_constructible<__filebuf_type, const _Path&, ios_base::openmode>>>
545 basic_ifstream(const _Path& __s,
546 ios_base::openmode __mode = ios_base::in)
547 : basic_ifstream(__s.c_str(), __mode)
551 basic_ifstream(const basic_ifstream&) = delete;
553 basic_ifstream(basic_ifstream&& __rhs)
554 : __istream_type(std::move(__rhs)),
555 _M_filebuf(std::move(__rhs._M_filebuf))
556 { __istream_type::set_rdbuf(&_M_filebuf); }
560 * @brief The destructor does nothing.
562 * The file is closed by the filebuf object, not the formatting
568 #if __cplusplus >= 201103L
569 // 27.8.3.2 Assign and swap:
572 operator=(const basic_ifstream&) = delete;
575 operator=(basic_ifstream&& __rhs)
577 __istream_type::operator=(std::move(__rhs));
578 _M_filebuf = std::move(__rhs._M_filebuf);
583 swap(basic_ifstream& __rhs)
585 __istream_type::swap(__rhs);
586 _M_filebuf.swap(__rhs._M_filebuf);
592 * @brief Accessing the underlying buffer.
593 * @return The current basic_filebuf buffer.
595 * This hides both signatures of std::basic_ios::rdbuf().
599 { return const_cast<__filebuf_type*>(&_M_filebuf); }
602 * @brief Wrapper to test for an open file.
603 * @return @c rdbuf()->is_open()
607 { return _M_filebuf.is_open(); }
609 // _GLIBCXX_RESOLVE_LIB_DEFECTS
610 // 365. Lack of const-qualification in clause 27
613 { return _M_filebuf.is_open(); }
616 * @brief Opens an external file.
617 * @param __s The name of the file.
618 * @param __mode The open mode flags.
620 * Calls @c std::basic_filebuf::open(s,__mode|in). If that function
621 * fails, @c failbit is set in the stream's error state.
624 open(const char* __s, ios_base::openmode __mode = ios_base::in)
626 if (!_M_filebuf.open(__s, __mode | ios_base::in))
627 this->setstate(ios_base::failbit);
629 // _GLIBCXX_RESOLVE_LIB_DEFECTS
630 // 409. Closing an fstream should clear error state
634 #if __cplusplus >= 201103L
636 * @brief Opens an external file.
637 * @param __s The name of the file.
638 * @param __mode The open mode flags.
640 * Calls @c std::basic_filebuf::open(__s,__mode|in). If that function
641 * fails, @c failbit is set in the stream's error state.
644 open(const std::string& __s, ios_base::openmode __mode = ios_base::in)
646 if (!_M_filebuf.open(__s, __mode | ios_base::in))
647 this->setstate(ios_base::failbit);
649 // _GLIBCXX_RESOLVE_LIB_DEFECTS
650 // 409. Closing an fstream should clear error state
654 #if __cplusplus >= 201703L
656 * @brief Opens an external file.
657 * @param __s The name of the file, as a filesystem::path.
658 * @param __mode The open mode flags.
660 * Calls @c std::basic_filebuf::open(__s,__mode|in). If that function
661 * fails, @c failbit is set in the stream's error state.
663 template<typename _Path>
665 open(const _Path& __s, ios_base::openmode __mode = ios_base::in)
666 -> decltype((void)_M_filebuf.open(__s, __mode))
667 { open(__s.c_str(), __mode); }
672 * @brief Close the file.
674 * Calls @c std::basic_filebuf::close(). If that function
675 * fails, @c failbit is set in the stream's error state.
680 if (!_M_filebuf.close())
681 this->setstate(ios_base::failbit);
686 // [27.8.1.8] Template class basic_ofstream
688 * @brief Controlling output for files.
691 * @tparam _CharT Type of character stream.
692 * @tparam _Traits Traits for character type, defaults to
693 * char_traits<_CharT>.
695 * This class supports reading from named files, using the inherited
696 * functions from std::basic_ostream. To control the associated
697 * sequence, an instance of std::basic_filebuf is used, which this page
698 * refers to as @c sb.
700 template<typename _CharT, typename _Traits>
701 class basic_ofstream : public basic_ostream<_CharT,_Traits>
705 typedef _CharT char_type;
706 typedef _Traits traits_type;
707 typedef typename traits_type::int_type int_type;
708 typedef typename traits_type::pos_type pos_type;
709 typedef typename traits_type::off_type off_type;
711 // Non-standard types:
712 typedef basic_filebuf<char_type, traits_type> __filebuf_type;
713 typedef basic_ostream<char_type, traits_type> __ostream_type;
716 __filebuf_type _M_filebuf;
721 * @brief Default constructor.
723 * Initializes @c sb using its default constructor, and passes
724 * @c &sb to the base class initializer. Does not open any files
725 * (you haven't given it a filename to open).
727 basic_ofstream(): __ostream_type(), _M_filebuf()
728 { this->init(&_M_filebuf); }
731 * @brief Create an output file stream.
732 * @param __s Null terminated string specifying the filename.
733 * @param __mode Open file in specified mode (see std::ios_base).
735 * @c ios_base::out is automatically included in @a __mode.
738 basic_ofstream(const char* __s,
739 ios_base::openmode __mode = ios_base::out)
740 : __ostream_type(), _M_filebuf()
742 this->init(&_M_filebuf);
743 this->open(__s, __mode);
746 #if __cplusplus >= 201103L
748 * @brief Create an output file stream.
749 * @param __s std::string specifying the filename.
750 * @param __mode Open file in specified mode (see std::ios_base).
752 * @c ios_base::out is automatically included in @a __mode.
755 basic_ofstream(const std::string& __s,
756 ios_base::openmode __mode = ios_base::out)
757 : __ostream_type(), _M_filebuf()
759 this->init(&_M_filebuf);
760 this->open(__s, __mode);
763 #if __cplusplus >= 201703L
765 * @param Create an output file stream.
766 * @param __s filesystem::path specifying the filename.
767 * @param __mode Open file in specified mode (see std::ios_base).
769 * @c ios_base::out is automatically included in @a __mode.
771 template<typename _Path, typename = _Require<
772 is_constructible<__filebuf_type, const _Path&, ios_base::openmode>>>
773 basic_ofstream(const _Path& __s,
774 ios_base::openmode __mode = ios_base::out)
775 : basic_ofstream(__s.c_str(), __mode)
779 basic_ofstream(const basic_ofstream&) = delete;
781 basic_ofstream(basic_ofstream&& __rhs)
782 : __ostream_type(std::move(__rhs)),
783 _M_filebuf(std::move(__rhs._M_filebuf))
784 { __ostream_type::set_rdbuf(&_M_filebuf); }
788 * @brief The destructor does nothing.
790 * The file is closed by the filebuf object, not the formatting
796 #if __cplusplus >= 201103L
797 // 27.8.3.2 Assign and swap:
800 operator=(const basic_ofstream&) = delete;
803 operator=(basic_ofstream&& __rhs)
805 __ostream_type::operator=(std::move(__rhs));
806 _M_filebuf = std::move(__rhs._M_filebuf);
811 swap(basic_ofstream& __rhs)
813 __ostream_type::swap(__rhs);
814 _M_filebuf.swap(__rhs._M_filebuf);
820 * @brief Accessing the underlying buffer.
821 * @return The current basic_filebuf buffer.
823 * This hides both signatures of std::basic_ios::rdbuf().
827 { return const_cast<__filebuf_type*>(&_M_filebuf); }
830 * @brief Wrapper to test for an open file.
831 * @return @c rdbuf()->is_open()
835 { return _M_filebuf.is_open(); }
837 // _GLIBCXX_RESOLVE_LIB_DEFECTS
838 // 365. Lack of const-qualification in clause 27
841 { return _M_filebuf.is_open(); }
844 * @brief Opens an external file.
845 * @param __s The name of the file.
846 * @param __mode The open mode flags.
848 * Calls @c std::basic_filebuf::open(__s,__mode|out). If that
849 * function fails, @c failbit is set in the stream's error state.
852 open(const char* __s, ios_base::openmode __mode = ios_base::out)
854 if (!_M_filebuf.open(__s, __mode | ios_base::out))
855 this->setstate(ios_base::failbit);
857 // _GLIBCXX_RESOLVE_LIB_DEFECTS
858 // 409. Closing an fstream should clear error state
862 #if __cplusplus >= 201103L
864 * @brief Opens an external file.
865 * @param __s The name of the file.
866 * @param __mode The open mode flags.
868 * Calls @c std::basic_filebuf::open(s,mode|out). If that
869 * function fails, @c failbit is set in the stream's error state.
872 open(const std::string& __s, ios_base::openmode __mode = ios_base::out)
874 if (!_M_filebuf.open(__s, __mode | ios_base::out))
875 this->setstate(ios_base::failbit);
877 // _GLIBCXX_RESOLVE_LIB_DEFECTS
878 // 409. Closing an fstream should clear error state
882 #if __cplusplus >= 201703L
884 * @brief Opens an external file.
885 * @param __s The name of the file, as a filesystem::path.
886 * @param __mode The open mode flags.
888 * Calls @c std::basic_filebuf::open(__s,__mode|out). If that
889 * function fails, @c failbit is set in the stream's error state.
891 template<typename _Path>
893 open(const _Path& __s, ios_base::openmode __mode = ios_base::out)
894 -> decltype((void)_M_filebuf.open(__s, __mode))
895 { open(__s.c_str(), __mode); }
900 * @brief Close the file.
902 * Calls @c std::basic_filebuf::close(). If that function
903 * fails, @c failbit is set in the stream's error state.
908 if (!_M_filebuf.close())
909 this->setstate(ios_base::failbit);
914 // [27.8.1.11] Template class basic_fstream
916 * @brief Controlling input and output for files.
919 * @tparam _CharT Type of character stream.
920 * @tparam _Traits Traits for character type, defaults to
921 * char_traits<_CharT>.
923 * This class supports reading from and writing to named files, using
924 * the inherited functions from std::basic_iostream. To control the
925 * associated sequence, an instance of std::basic_filebuf is used, which
926 * this page refers to as @c sb.
928 template<typename _CharT, typename _Traits>
929 class basic_fstream : public basic_iostream<_CharT, _Traits>
933 typedef _CharT char_type;
934 typedef _Traits traits_type;
935 typedef typename traits_type::int_type int_type;
936 typedef typename traits_type::pos_type pos_type;
937 typedef typename traits_type::off_type off_type;
939 // Non-standard types:
940 typedef basic_filebuf<char_type, traits_type> __filebuf_type;
941 typedef basic_ios<char_type, traits_type> __ios_type;
942 typedef basic_iostream<char_type, traits_type> __iostream_type;
945 __filebuf_type _M_filebuf;
948 // Constructors/destructor:
950 * @brief Default constructor.
952 * Initializes @c sb using its default constructor, and passes
953 * @c &sb to the base class initializer. Does not open any files
954 * (you haven't given it a filename to open).
957 : __iostream_type(), _M_filebuf()
958 { this->init(&_M_filebuf); }
961 * @brief Create an input/output file stream.
962 * @param __s Null terminated string specifying the filename.
963 * @param __mode Open file in specified mode (see std::ios_base).
966 basic_fstream(const char* __s,
967 ios_base::openmode __mode = ios_base::in | ios_base::out)
968 : __iostream_type(0), _M_filebuf()
970 this->init(&_M_filebuf);
971 this->open(__s, __mode);
974 #if __cplusplus >= 201103L
976 * @brief Create an input/output file stream.
977 * @param __s Null terminated string specifying the filename.
978 * @param __mode Open file in specified mode (see std::ios_base).
981 basic_fstream(const std::string& __s,
982 ios_base::openmode __mode = ios_base::in | ios_base::out)
983 : __iostream_type(0), _M_filebuf()
985 this->init(&_M_filebuf);
986 this->open(__s, __mode);
989 #if __cplusplus >= 201703L
991 * @param Create an input/output file stream.
992 * @param __s filesystem::path specifying the filename.
993 * @param __mode Open file in specified mode (see std::ios_base).
995 template<typename _Path, typename = _Require<
996 is_constructible<__filebuf_type, const _Path&, ios_base::openmode>>>
997 basic_fstream(const _Path& __s,
998 ios_base::openmode __mode = ios_base::in | ios_base::out)
999 : basic_fstream(__s.c_str(), __mode)
1003 basic_fstream(const basic_fstream&) = delete;
1005 basic_fstream(basic_fstream&& __rhs)
1006 : __iostream_type(std::move(__rhs)),
1007 _M_filebuf(std::move(__rhs._M_filebuf))
1008 { __iostream_type::set_rdbuf(&_M_filebuf); }
1012 * @brief The destructor does nothing.
1014 * The file is closed by the filebuf object, not the formatting
1020 #if __cplusplus >= 201103L
1021 // 27.8.3.2 Assign and swap:
1024 operator=(const basic_fstream&) = delete;
1027 operator=(basic_fstream&& __rhs)
1029 __iostream_type::operator=(std::move(__rhs));
1030 _M_filebuf = std::move(__rhs._M_filebuf);
1035 swap(basic_fstream& __rhs)
1037 __iostream_type::swap(__rhs);
1038 _M_filebuf.swap(__rhs._M_filebuf);
1044 * @brief Accessing the underlying buffer.
1045 * @return The current basic_filebuf buffer.
1047 * This hides both signatures of std::basic_ios::rdbuf().
1051 { return const_cast<__filebuf_type*>(&_M_filebuf); }
1054 * @brief Wrapper to test for an open file.
1055 * @return @c rdbuf()->is_open()
1059 { return _M_filebuf.is_open(); }
1061 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1062 // 365. Lack of const-qualification in clause 27
1065 { return _M_filebuf.is_open(); }
1068 * @brief Opens an external file.
1069 * @param __s The name of the file.
1070 * @param __mode The open mode flags.
1072 * Calls @c std::basic_filebuf::open(__s,__mode). If that
1073 * function fails, @c failbit is set in the stream's error state.
1076 open(const char* __s,
1077 ios_base::openmode __mode = ios_base::in | ios_base::out)
1079 if (!_M_filebuf.open(__s, __mode))
1080 this->setstate(ios_base::failbit);
1082 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1083 // 409. Closing an fstream should clear error state
1087 #if __cplusplus >= 201103L
1089 * @brief Opens an external file.
1090 * @param __s The name of the file.
1091 * @param __mode The open mode flags.
1093 * Calls @c std::basic_filebuf::open(__s,__mode). If that
1094 * function fails, @c failbit is set in the stream's error state.
1097 open(const std::string& __s,
1098 ios_base::openmode __mode = ios_base::in | ios_base::out)
1100 if (!_M_filebuf.open(__s, __mode))
1101 this->setstate(ios_base::failbit);
1103 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1104 // 409. Closing an fstream should clear error state
1108 #if __cplusplus >= 201703L
1110 * @brief Opens an external file.
1111 * @param __s The name of the file, as a filesystem::path.
1112 * @param __mode The open mode flags.
1114 * Calls @c std::basic_filebuf::open(__s,__mode). If that
1115 * function fails, @c failbit is set in the stream's error state.
1117 template<typename _Path>
1119 open(const _Path& __s,
1120 ios_base::openmode __mode = ios_base::in | ios_base::out)
1121 -> decltype((void)_M_filebuf.open(__s, __mode))
1122 { open(__s.c_str(), __mode); }
1127 * @brief Close the file.
1129 * Calls @c std::basic_filebuf::close(). If that function
1130 * fails, @c failbit is set in the stream's error state.
1135 if (!_M_filebuf.close())
1136 this->setstate(ios_base::failbit);
1140 #if __cplusplus >= 201103L
1141 /// Swap specialization for filebufs.
1142 template <class _CharT, class _Traits>
1144 swap(basic_filebuf<_CharT, _Traits>& __x,
1145 basic_filebuf<_CharT, _Traits>& __y)
1148 /// Swap specialization for ifstreams.
1149 template <class _CharT, class _Traits>
1151 swap(basic_ifstream<_CharT, _Traits>& __x,
1152 basic_ifstream<_CharT, _Traits>& __y)
1155 /// Swap specialization for ofstreams.
1156 template <class _CharT, class _Traits>
1158 swap(basic_ofstream<_CharT, _Traits>& __x,
1159 basic_ofstream<_CharT, _Traits>& __y)
1162 /// Swap specialization for fstreams.
1163 template <class _CharT, class _Traits>
1165 swap(basic_fstream<_CharT, _Traits>& __x,
1166 basic_fstream<_CharT, _Traits>& __y)
1170 _GLIBCXX_END_NAMESPACE_VERSION
1173 #include <bits/fstream.tcc>
1175 #endif /* _GLIBCXX_FSTREAM */