Public Types
-
typedef codecvt< char_type,
char, __state_type > __codecvt_type - typedef __basic_file< char > __file_type
-
typedef basic_filebuf
< char_type, traits_type > __filebuf_type - typedef traits_type::state_type __state_type
- typedef basic_streambuf
< char_type, traits_type > __streambuf_type - typedef _CharT char_type
- typedef traits_type::int_type int_type
- typedef traits_type::off_type off_type
- typedef traits_type::pos_type pos_type
- typedef _Traits traits_type
Public Member Functions
- basic_filebuf ()
- virtual ~basic_filebuf ()
- __filebuf_type * close ()
- streamsize in_avail ()
- bool is_open () const throw ()
- __filebuf_type * open (const char *__s, ios_base::openmode __mode)
- __filebuf_type * open (const std::string &__s, ios_base::openmode __mode)
- int_type sbumpc ()
- int_type sgetc ()
- streamsize sgetn (char_type *__s, streamsize __n)
- int_type snextc ()
- int_type sputbackc (char_type __c)
- int_type sputc (char_type __c)
- streamsize sputn (const char_type *__s, streamsize __n)
- int_type sungetc ()
Protected Member Functions
- void __safe_gbump (streamsize __n)
- void __safe_pbump (streamsize __n)
- void _M_allocate_internal_buffer ()
- bool _M_convert_to_external (char_type *, streamsize)
- void _M_create_pback ()
- void _M_destroy_internal_buffer () throw ()
- void _M_destroy_pback () throw ()
- int _M_get_ext_pos (__state_type &__state)
- pos_type _M_seek (off_type __off, ios_base::seekdir __way, __state_type __state)
- void _M_set_buffer (streamsize __off)
- bool _M_terminate_output ()
- void gbump (int __n)
- virtual void imbue (const locale &__loc)
- virtual int_type overflow (int_type __c=_Traits::eof())
- virtual int_type pbackfail (int_type __c=_Traits::eof())
- void pbump (int __n)
- virtual pos_type seekoff (off_type __off, ios_base::seekdir __way, ios_base::openmode __mode=ios_base::in|ios_base::out)
- virtual pos_type seekpos (pos_type __pos, ios_base::openmode __mode=ios_base::in|ios_base::out)
- virtual __streambuf_type * setbuf (char_type *__s, streamsize __n)
- void setg (char_type *__gbeg, char_type *__gnext, char_type *__gend)
- void setp (char_type *__pbeg, char_type *__pend)
- virtual streamsize showmanyc ()
- virtual int sync ()
- virtual int_type uflow ()
- virtual int_type underflow ()
- virtual streamsize xsgetn (char_type *__s, streamsize __n)
- virtual streamsize xsputn (const char_type *__s, streamsize __n)
Protected Attributes
- char_type * _M_buf
- bool _M_buf_allocated
- size_t _M_buf_size
- const __codecvt_type * _M_codecvt
- char * _M_ext_buf
- streamsize _M_ext_buf_size
- char * _M_ext_end
- const char * _M_ext_next
- __file_type _M_file
- __c_lock _M_lock
- ios_base::openmode _M_mode
- bool _M_reading
- __state_type _M_state_beg
- __state_type _M_state_cur
- __state_type _M_state_last
- bool _M_writing
Friends
-
template<bool _IsMove, typename _CharT2 > __gnu_cxx::__enable_if
< __is_char< _CharT2 >
::__value, _CharT2 * >::__type __copy_move_a2 (istreambuf_iterator< _CharT2 >, istreambuf_iterator< _CharT2 >, _CharT2 *) - streamsize __copy_streambufs_eof (__streambuf_type *, __streambuf_type *, bool &)
- class basic_ios< char_type, traits_type >
- class basic_istream< char_type, traits_type >
- class basic_ostream< char_type, traits_type >
-
template<typename _CharT2 > __gnu_cxx::__enable_if
< __is_char< _CharT2 >
::__value, istreambuf_iterator
< _CharT2 > >::__type find (istreambuf_iterator< _CharT2 >, istreambuf_iterator< _CharT2 >, const _CharT2 &) -
template<typename _CharT2 , typename _Traits2 , typename _Alloc > basic_istream< _CharT2,
_Traits2 > & getline (basic_istream< _CharT2, _Traits2 > &, basic_string< _CharT2, _Traits2, _Alloc > &, _CharT2) - class ios_base
- class istreambuf_iterator< char_type, traits_type >
-
template<typename _CharT2 , typename _Traits2 > basic_istream< _CharT2,
_Traits2 > & operator>> (basic_istream< _CharT2, _Traits2 > &, _CharT2 *) -
template<typename _CharT2 , typename _Traits2 , typename _Alloc > basic_istream< _CharT2,
_Traits2 > & operator>> (basic_istream< _CharT2, _Traits2 > &, basic_string< _CharT2, _Traits2, _Alloc > &) - class ostreambuf_iterator< char_type, traits_type >
- char_type * _M_in_beg
- char_type * _M_in_cur
- char_type * _M_in_end
- char_type * _M_out_beg
- char_type * _M_out_cur
- char_type * _M_out_end
- locale _M_buf_locale
- locale pubimbue (const locale &__loc)
- locale getloc () const
- __streambuf_type * pubsetbuf (char_type *__s, streamsize __n)
- pos_type pubseekoff (off_type __off, ios_base::seekdir __way, ios_base::openmode __mode=ios_base::in|ios_base::out)
- pos_type pubseekpos (pos_type __sp, ios_base::openmode __mode=ios_base::in|ios_base::out)
- int pubsync ()
Detailed Description
template<typename _CharT, typename _Traits>
class std::basic_filebuf< _CharT, _Traits >
The actual work of input and output (for files).
This class associates both its input and output sequence with an external disk file, and maintains a joint file position for both sequences. Many of its semantics are described in terms of similar behavior in the Standard C Library's FILE streams.
Member Typedef Documentation
| typedef basic_streambuf<char_type, traits_type> std::basic_filebuf< _CharT, _Traits >::__streambuf_type |
This is a non-standard type.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
| typedef _CharT std::basic_filebuf< _CharT, _Traits >::char_type |
These are standard types. They permit a standardized way of referring to names of (or names dependant on) the template parameters, which are specific to the implementation.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Reimplemented in __gnu_cxx::stdio_filebuf< _CharT, _Traits >.
| typedef traits_type::int_type std::basic_filebuf< _CharT, _Traits >::int_type |
These are standard types. They permit a standardized way of referring to names of (or names dependant on) the template parameters, which are specific to the implementation.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Reimplemented in __gnu_cxx::stdio_filebuf< _CharT, _Traits >.
| typedef traits_type::off_type std::basic_filebuf< _CharT, _Traits >::off_type |
These are standard types. They permit a standardized way of referring to names of (or names dependant on) the template parameters, which are specific to the implementation.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Reimplemented in __gnu_cxx::stdio_filebuf< _CharT, _Traits >.
| typedef traits_type::pos_type std::basic_filebuf< _CharT, _Traits >::pos_type |
These are standard types. They permit a standardized way of referring to names of (or names dependant on) the template parameters, which are specific to the implementation.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Reimplemented in __gnu_cxx::stdio_filebuf< _CharT, _Traits >, and __gnu_cxx::enc_filebuf< _CharT >.
| typedef _Traits std::basic_filebuf< _CharT, _Traits >::traits_type |
These are standard types. They permit a standardized way of referring to names of (or names dependant on) the template parameters, which are specific to the implementation.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Reimplemented in __gnu_cxx::stdio_filebuf< _CharT, _Traits >, and __gnu_cxx::enc_filebuf< _CharT >.
Constructor & Destructor Documentation
| std::basic_filebuf< _CharT, _Traits >::basic_filebuf | ( | ) |
Does not open any files.
The default constructor initializes the parent class using its own default ctor.
Definition at line 81 of file fstream.tcc.
References std::basic_streambuf< _CharT, _Traits >::_M_buf_locale.
| virtual std::basic_filebuf< _CharT, _Traits >::~basic_filebuf | ( | ) | [inline, virtual] |
Member Function Documentation
| void std::basic_filebuf< _CharT, _Traits >::_M_create_pback | ( | ) | [inline, protected] |
| void std::basic_filebuf< _CharT, _Traits >::_M_destroy_pback | ( | ) | throw () [inline, protected] |
| void std::basic_filebuf< _CharT, _Traits >::_M_set_buffer | ( | streamsize | __off | ) | [inline, protected] |
This function sets the pointers of the internal buffer, both get and put areas. Typically:
__off == egptr() - eback() upon underflow/uflow (read mode); __off == 0 upon overflow (write mode); __off == -1 upon open, setbuf, seekoff/pos (uncommitted mode).
NB: epptr() - pbase() == _M_buf_size - 1, since _M_buf_size reflects the actual allocated memory and the last cell is reserved for the overflow char of a full put area.
| basic_filebuf< _CharT, _Traits >::__filebuf_type * std::basic_filebuf< _CharT, _Traits >::close | ( | ) |
Closes the currently associated file.
- Returns:
thison success, NULL on failure
If no file is currently open, this function immediately fails.
If a put buffer area exists, overflow(eof) is called to flush all the characters. The file is then closed.
If any operations fail, this function also fails.
Definition at line 130 of file fstream.tcc.
Referenced by std::basic_ifstream< _CharT, _Traits >::close(), std::basic_ofstream< _CharT, _Traits >::close(), std::basic_fstream< _CharT, _Traits >::close(), and std::basic_filebuf< char_type, traits_type >::~basic_filebuf().
| char_type* std::basic_streambuf< _CharT, _Traits >::eback | ( | ) | const [inline, protected, inherited] |
Access to the get area.
These functions are only available to other protected functions, including derived classes.
- eback() returns the beginning pointer for the input sequence
Definition at line 480 of file streambuf.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_destroy_pback(), std::basic_streambuf< char_type, traits_type >::sputbackc(), and std::basic_streambuf< char_type, traits_type >::sungetc().
| char_type* std::basic_streambuf< _CharT, _Traits >::egptr | ( | ) | const [inline, protected, inherited] |
Access to the get area.
These functions are only available to other protected functions, including derived classes.
- eback() returns the beginning pointer for the input sequence
Definition at line 486 of file streambuf.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_create_pback(), std::basic_streambuf< char_type, traits_type >::in_avail(), std::basic_streambuf< char_type, traits_type >::sbumpc(), std::basic_streambuf< char_type, traits_type >::sgetc(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::showmanyc(), and std::basic_stringbuf< _CharT, _Traits, _Alloc >::str().
| char_type* std::basic_streambuf< _CharT, _Traits >::epptr | ( | ) | const [inline, protected, inherited] |
Access to the put area.
These functions are only available to other protected functions, including derived classes.
- pbase() returns the beginning pointer for the output sequence
Definition at line 533 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::sputc().
| void std::basic_streambuf< _CharT, _Traits >::gbump | ( | int | __n | ) | [inline, protected, inherited] |
Moving the read position.
- Parameters:
-
__n The delta by which to move.
This just advances the read position without returning any data.
Definition at line 496 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::sbumpc(), std::basic_streambuf< char_type, traits_type >::sputbackc(), std::basic_streambuf< char_type, traits_type >::sungetc(), and std::basic_streambuf< char_type, traits_type >::uflow().
| locale std::basic_streambuf< _CharT, _Traits >::getloc | ( | ) | const [inline, inherited] |
Locale access.
- Returns:
- The current locale in effect.
If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.
Definition at line 224 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::pubimbue().
| char_type* std::basic_streambuf< _CharT, _Traits >::gptr | ( | ) | const [inline, protected, inherited] |
Access to the get area.
These functions are only available to other protected functions, including derived classes.
- eback() returns the beginning pointer for the input sequence
Definition at line 483 of file streambuf.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_create_pback(), std::basic_filebuf< char_type, traits_type >::_M_destroy_pback(), std::basic_streambuf< char_type, traits_type >::in_avail(), std::basic_streambuf< char_type, traits_type >::sbumpc(), std::basic_streambuf< char_type, traits_type >::sgetc(), std::basic_stringbuf< _CharT, _Traits, _Alloc >::showmanyc(), std::basic_streambuf< char_type, traits_type >::sputbackc(), std::basic_streambuf< char_type, traits_type >::sungetc(), and std::basic_streambuf< char_type, traits_type >::uflow().
| void std::basic_filebuf< _CharT, _Traits >::imbue | ( | const locale & | __loc | ) | [protected, virtual] |
Changes translations.
- Parameters:
-
__loc A new locale.
Translations done during I/O which depend on the current locale are changed by this call. The standard adds, Between invocations of this function a class derived from streambuf can safely cache results of calls to locale functions and to members of facets so obtained.
- Note:
- Base class version does nothing.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 912 of file fstream.tcc.
References std::ios_base::cur.
| streamsize std::basic_streambuf< _CharT, _Traits >::in_avail | ( | ) | [inline, inherited] |
Looking ahead into the stream.
- Returns:
- The number of characters available.
If a read position is available, returns the number of characters available for reading before the buffer must be refilled. Otherwise returns the derived showmanyc().
| bool std::basic_filebuf< _CharT, _Traits >::is_open | ( | ) | const throw () [inline] |
Returns true if the external file is open.
Definition at line 224 of file fstream.
Referenced by std::basic_ifstream< _CharT, _Traits >::is_open(), std::basic_ofstream< _CharT, _Traits >::is_open(), and std::basic_fstream< _CharT, _Traits >::is_open().
| basic_filebuf< _CharT, _Traits >::__filebuf_type * std::basic_filebuf< _CharT, _Traits >::open | ( | const char * | __s, |
| ios_base::openmode | __mode | ||
| ) |
Opens an external file.
- Parameters:
-
__s The name of the file. __mode The open mode flags.
- Returns:
thison success, NULL on failure
If a file is already open, this function immediately fails. Otherwise it tries to open the file named __s using the flags given in mode.
Table 92, adapted here, gives the relation between openmode combinations and the equivalent fopen() flags. (NB: lines app, in|out|app, in|app, binary|app, binary|in|out|app, and binary|in|app per DR 596) +---------------------------------------------------------+ | ios_base Flag combination stdio equivalent | |binary in out trunc app | +---------------------------------------------------------+ | + w | | + + a | | + a | | + + w | | + r | | + + r+ | | + + + w+ | | + + + a+ | | + + a+ | +---------------------------------------------------------+ | + + wb | | + + + ab | | + + ab | | + + + wb | | + + rb | | + + + r+b | | + + + + w+b | | + + + + a+b | | + + + a+b | +---------------------------------------------------------+
Definition at line 96 of file fstream.tcc.
References std::ios_base::ate, std::ios_base::end, and std::basic_filebuf< _CharT, _Traits >::open().
Referenced by std::basic_filebuf< _CharT, _Traits >::open(), std::basic_ifstream< _CharT, _Traits >::open(), std::basic_ofstream< _CharT, _Traits >::open(), and std::basic_fstream< _CharT, _Traits >::open().
| __filebuf_type* std::basic_filebuf< _CharT, _Traits >::open | ( | const std::string & | __s, |
| ios_base::openmode | __mode | ||
| ) | [inline] |
Opens an external file.
- Parameters:
-
__s The name of the file. __mode The open mode flags.
- Returns:
thison success, NULL on failure
Definition at line 277 of file fstream.
Referenced by std::basic_filebuf< char_type, traits_type >::open().
| basic_filebuf< _CharT, _Traits >::int_type std::basic_filebuf< _CharT, _Traits >::overflow | ( | int_type | __c = _Traits::eof() | ) | [protected, virtual] |
Consumes data from the buffer; writes to the controlled sequence.
- Parameters:
-
__c An additional character to consume.
- Returns:
- eof() to indicate failure, something else (usually __c, or not_eof())
Informally, this function is called when the output buffer is full (or does not exist, as buffering need not actually be done). If a buffer exists, it is consumed, with some effect on the controlled sequence. (Typically, the buffer is written out to the sequence verbatim.) In either case, the character c is also written out, if __c is not eof().
For a formal definition of this function, see a good text such as Langer & Kreft, or [27.5.2.4.5]/3-7.
A functioning output streambuf can be created by overriding only this function (no buffer area will be used).
- Note:
- Base class version does nothing, returns eof().
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 424 of file fstream.tcc.
References std::ios_base::cur, and std::ios_base::out.
| basic_filebuf< _CharT, _Traits >::int_type std::basic_filebuf< _CharT, _Traits >::pbackfail | ( | int_type | __c = _Traits::eof() | ) | [protected, virtual] |
Tries to back up the input sequence.
- Parameters:
-
__c The character to be inserted back into the sequence.
- Returns:
- eof() on failure, some other value on success
- Postcondition:
- The constraints of
gptr(),eback(), andpptr()are the same as forunderflow().
- Note:
- Base class version does nothing, returns eof().
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 365 of file fstream.tcc.
References std::ios_base::cur, and std::ios_base::in.
| char_type* std::basic_streambuf< _CharT, _Traits >::pbase | ( | ) | const [inline, protected, inherited] |
Access to the put area.
These functions are only available to other protected functions, including derived classes.
- pbase() returns the beginning pointer for the output sequence
Definition at line 527 of file streambuf.
Referenced by std::basic_stringbuf< _CharT, _Traits, _Alloc >::str().
| void std::basic_streambuf< _CharT, _Traits >::pbump | ( | int | __n | ) | [inline, protected, inherited] |
Moving the write position.
- Parameters:
-
__n The delta by which to move.
This just advances the write position without returning any data.
Definition at line 543 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::sputc().
| char_type* std::basic_streambuf< _CharT, _Traits >::pptr | ( | ) | const [inline, protected, inherited] |
Access to the put area.
These functions are only available to other protected functions, including derived classes.
- pbase() returns the beginning pointer for the output sequence
Definition at line 530 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::sputc(), and std::basic_stringbuf< _CharT, _Traits, _Alloc >::str().
| locale std::basic_streambuf< _CharT, _Traits >::pubimbue | ( | const locale & | __loc | ) | [inline, inherited] |
| pos_type std::basic_streambuf< _CharT, _Traits >::pubseekoff | ( | off_type | __off, |
| ios_base::seekdir | __way, | ||
| ios_base::openmode | __mode = ios_base::in | ios_base::out |
||
| ) | [inline, inherited] |
Alters the stream position.
- Parameters:
-
__off Offset. __way Value for ios_base::seekdir. __mode Value for ios_base::openmode.
Calls virtual seekoff function.
| pos_type std::basic_streambuf< _CharT, _Traits >::pubseekpos | ( | pos_type | __sp, |
| ios_base::openmode | __mode = ios_base::in | ios_base::out |
||
| ) | [inline, inherited] |
Alters the stream position.
- Parameters:
-
__sp Position __mode Value for ios_base::openmode.
Calls virtual seekpos function.
| __streambuf_type* std::basic_streambuf< _CharT, _Traits >::pubsetbuf | ( | char_type * | __s, |
| streamsize | __n | ||
| ) | [inline, inherited] |
| int std::basic_streambuf< _CharT, _Traits >::pubsync | ( | ) | [inline, inherited] |
Calls virtual sync function.
Definition at line 269 of file streambuf.
Referenced by std::basic_istream< _CharT, _Traits >::sync().
| int_type std::basic_streambuf< _CharT, _Traits >::sbumpc | ( | ) | [inline, inherited] |
Getting the next character.
- Returns:
- The next character, or eof.
If the input read position is available, returns that character and increments the read pointer, otherwise calls and returns uflow().
Definition at line 314 of file streambuf.
Referenced by std::basic_istream< _CharT, _Traits >::getline(), std::basic_istream< _CharT, _Traits >::ignore(), std::istreambuf_iterator< _CharT, _Traits >::operator++(), and std::basic_streambuf< char_type, traits_type >::snextc().
| basic_filebuf< _CharT, _Traits >::pos_type std::basic_filebuf< _CharT, _Traits >::seekoff | ( | off_type | , |
| ios_base::seekdir | , | ||
| ios_base::openmode | = ios_base::in | ios_base::out |
||
| ) | [protected, virtual] |
Alters the stream positions.
Each derived class provides its own appropriate behavior.
- Note:
- Base class version does nothing, returns a
pos_typethat represents an invalid stream position.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 715 of file fstream.tcc.
References std::ios_base::cur.
| basic_filebuf< _CharT, _Traits >::pos_type std::basic_filebuf< _CharT, _Traits >::seekpos | ( | pos_type | , |
| ios_base::openmode | = ios_base::in | ios_base::out |
||
| ) | [protected, virtual] |
Alters the stream positions.
Each derived class provides its own appropriate behavior.
- Note:
- Base class version does nothing, returns a
pos_typethat represents an invalid stream position.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 775 of file fstream.tcc.
References std::ios_base::beg.
| basic_filebuf< _CharT, _Traits >::__streambuf_type * std::basic_filebuf< _CharT, _Traits >::setbuf | ( | char_type * | __s, |
| streamsize | __n | ||
| ) | [protected, virtual] |
Manipulates the buffer.
- Parameters:
-
__s Pointer to a buffer area. __n Size of __s.
- Returns:
this
If no file has been opened, and both __s and __n are zero, then the stream becomes unbuffered. Otherwise, __s is used as a buffer; see http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html for more.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 686 of file fstream.tcc.
| void std::basic_streambuf< _CharT, _Traits >::setg | ( | char_type * | __gbeg, |
| char_type * | __gnext, | ||
| char_type * | __gend | ||
| ) | [inline, protected, inherited] |
Setting the three read area pointers.
- Parameters:
-
__gbeg A pointer. __gnext A pointer. __gend A pointer.
Definition at line 507 of file streambuf.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_create_pback(), std::basic_filebuf< char_type, traits_type >::_M_destroy_pback(), and std::basic_filebuf< char_type, traits_type >::_M_set_buffer().
| void std::basic_streambuf< _CharT, _Traits >::setp | ( | char_type * | __pbeg, |
| char_type * | __pend | ||
| ) | [inline, protected, inherited] |
| int_type std::basic_streambuf< _CharT, _Traits >::sgetc | ( | ) | [inline, inherited] |
Getting the next character.
- Returns:
- The next character, or eof.
If the input read position is available, returns that character, otherwise calls and returns underflow(). Does not move the read position after fetching the character.
Definition at line 336 of file streambuf.
Referenced by std::basic_istream< _CharT, _Traits >::get(), std::basic_istream< _CharT, _Traits >::getline(), std::basic_istream< _CharT, _Traits >::ignore(), std::basic_istream< _CharT, _Traits >::sentry::sentry(), and std::basic_streambuf< char_type, traits_type >::snextc().
| streamsize std::basic_streambuf< _CharT, _Traits >::sgetn | ( | char_type * | __s, |
| streamsize | __n | ||
| ) | [inline, inherited] |
| streamsize std::basic_filebuf< _CharT, _Traits >::showmanyc | ( | ) | [protected, virtual] |
Investigating the data available.
- Returns:
- An estimate of the number of characters available in the input sequence, or -1.
If it returns a positive value, then successive calls to underflow() will not return traits::eof() until at least that number of characters have been supplied. If showmanyc() returns -1, then calls to underflow() or uflow() will fail. [27.5.2.4.3]/1
- Note:
- Base class version does nothing, returns zero.
-
The standard adds that the intention is not only that the calls [to underflow or uflow] will not return
eof()but that they will return immediately. -
The standard adds that the morphemes of
showmanycare es-how-many-see, not show-manic.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 180 of file fstream.tcc.
References std::ios_base::binary, and std::ios_base::in.
| int_type std::basic_streambuf< _CharT, _Traits >::snextc | ( | ) | [inline, inherited] |
Getting the next character.
- Returns:
- The next character, or eof.
Calls sbumpc(), and if that function returns traits::eof(), so does this function. Otherwise, sgetc().
Definition at line 296 of file streambuf.
Referenced by std::basic_istream< _CharT, _Traits >::get(), std::basic_istream< _CharT, _Traits >::getline(), std::basic_istream< _CharT, _Traits >::ignore(), and std::basic_istream< _CharT, _Traits >::sentry::sentry().
| int_type std::basic_streambuf< _CharT, _Traits >::sputbackc | ( | char_type | __c | ) | [inline, inherited] |
Pushing characters back into the input stream.
- Parameters:
-
__c The character to push back.
- Returns:
- The previous character, if possible.
Similar to sungetc(), but __c is pushed onto the stream instead of the previous character. If successful, the next character fetched from the input stream will be __c.
Definition at line 370 of file streambuf.
Referenced by std::basic_istream< _CharT, _Traits >::putback().
| int_type std::basic_streambuf< _CharT, _Traits >::sputc | ( | char_type | __c | ) | [inline, inherited] |
Entry point for all single-character output functions.
- Parameters:
-
__c A character to output.
- Returns:
- __c, if possible.
One of two public output functions.
If a write position is available for the output sequence (i.e., the buffer is not full), stores __c in that position, increments the position, and returns traits::to_int_type(__c). If a write position is not available, returns overflow(__c).
Definition at line 422 of file streambuf.
Referenced by std::basic_istream< _CharT, _Traits >::get(), and std::ostreambuf_iterator< _CharT, _Traits >::operator=().
| streamsize std::basic_streambuf< _CharT, _Traits >::sputn | ( | const char_type * | __s, |
| streamsize | __n | ||
| ) | [inline, inherited] |
| int_type std::basic_streambuf< _CharT, _Traits >::sungetc | ( | ) | [inline, inherited] |
Moving backwards in the input stream.
- Returns:
- The previous character, if possible.
If a putback position is available, this function decrements the input pointer and returns that character. Otherwise, calls and returns pbackfail(). The effect is to unget the last character gotten.
Definition at line 395 of file streambuf.
Referenced by std::basic_istream< _CharT, _Traits >::unget().
| int std::basic_filebuf< _CharT, _Traits >::sync | ( | ) | [protected, virtual] |
Synchronizes the buffer arrays with the controlled sequences.
- Returns:
- -1 on failure.
Each derived class provides its own appropriate behavior, including the definition of failure.
- Note:
- Base class version does nothing, returns zero.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 895 of file fstream.tcc.
| virtual int_type std::basic_streambuf< _CharT, _Traits >::uflow | ( | ) | [inline, protected, virtual, inherited] |
Fetches more data from the controlled sequence.
- Returns:
- The first character from the pending sequence.
Informally, this function does the same thing as underflow(), and in fact is required to call that function. It also returns the new character, like underflow() does. However, this function also moves the read position forward by one.
Reimplemented in __gnu_cxx::stdio_sync_filebuf< _CharT, _Traits >.
Definition at line 698 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::sbumpc().
| basic_filebuf< _CharT, _Traits >::int_type std::basic_filebuf< _CharT, _Traits >::underflow | ( | ) | [protected, virtual] |
Fetches more data from the controlled sequence.
- Returns:
- The first character from the pending sequence.
Informally, this function is called when the input buffer is exhausted (or does not exist, as buffering need not actually be done). If a buffer exists, it is refilled. In either case, the next available character is returned, or traits::eof() to indicate a null pending sequence.
For a formal definition of the pending sequence, see a good text such as Langer & Kreft, or [27.5.2.4.3]/7-14.
A functioning input streambuf can be created by overriding only this function (no buffer area will be used). For an example, see http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25.html
- Note:
- Base class version does nothing, returns eof().
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 206 of file fstream.tcc.
References std::ios_base::in, and std::min().
| streamsize std::basic_filebuf< _CharT, _Traits >::xsgetn | ( | char_type * | __s, |
| streamsize | __n | ||
| ) | [protected, virtual] |
Multiple character extraction.
- Parameters:
-
__s A buffer area. __n Maximum number of characters to assign.
- Returns:
- The number of characters assigned.
Fills __s[0] through __s[__n-1] with characters from the input sequence, as if by sbumpc(). Stops when either __n characters have been copied, or when traits::eof() would be copied.
It is expected that derived classes provide a more efficient implementation by overriding this definition.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 551 of file fstream.tcc.
References std::ios_base::in.
| streamsize std::basic_filebuf< _CharT, _Traits >::xsputn | ( | const char_type * | __s, |
| streamsize | __n | ||
| ) | [protected, virtual] |
Multiple character insertion.
- Parameters:
-
__s A buffer area. __n Maximum number of characters to write.
- Returns:
- The number of characters written.
Writes __s[0] through __s[__n-1] to the output sequence, as if by sputc(). Stops when either n characters have been copied, or when sputc() would return traits::eof().
It is expected that derived classes provide a more efficient implementation by overriding this definition.
Reimplemented from std::basic_streambuf< _CharT, _Traits >.
Definition at line 639 of file fstream.tcc.
References std::min(), and std::ios_base::out.
Member Data Documentation
char_type* std::basic_filebuf< _CharT, _Traits >::_M_buf [protected] |
Pointer to the beginning of internal buffer.
Definition at line 111 of file fstream.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_destroy_pback(), and std::basic_filebuf< char_type, traits_type >::_M_set_buffer().
locale std::basic_streambuf< _CharT, _Traits >::_M_buf_locale [protected, inherited] |
Current locale setting.
Definition at line 190 of file streambuf.
Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf(), std::basic_streambuf< char_type, traits_type >::getloc(), and std::basic_streambuf< char_type, traits_type >::pubimbue().
size_t std::basic_filebuf< _CharT, _Traits >::_M_buf_size [protected] |
Actual size of internal buffer. This number is equal to the size of the put area + 1 position, reserved for the overflow char of a full area.
Definition at line 118 of file fstream.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_set_buffer().
char* std::basic_filebuf< _CharT, _Traits >::_M_ext_buf [protected] |
streamsize std::basic_filebuf< _CharT, _Traits >::_M_ext_buf_size [protected] |
const char* std::basic_filebuf< _CharT, _Traits >::_M_ext_next [protected] |
char_type* std::basic_streambuf< _CharT, _Traits >::_M_in_beg [protected, inherited] |
This is based on _IO_FILE, just reordered to be more consistent, and is intended to be the most minimal abstraction for an internal buffer.
- get == input == read
- put == output == write
Definition at line 182 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::eback(), and std::basic_streambuf< char_type, traits_type >::setg().
char_type* std::basic_streambuf< _CharT, _Traits >::_M_in_cur [protected, inherited] |
Entry point for imbue().
- Parameters:
-
__loc The new locale.
- Returns:
- The previous locale.
Calls the derived imbue(__loc).
Definition at line 183 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::gbump(), std::basic_streambuf< char_type, traits_type >::gptr(), and std::basic_streambuf< char_type, traits_type >::setg().
char_type* std::basic_streambuf< _CharT, _Traits >::_M_in_end [protected, inherited] |
Entry point for imbue().
- Parameters:
-
__loc The new locale.
- Returns:
- The previous locale.
Calls the derived imbue(__loc).
Definition at line 184 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::egptr(), and std::basic_streambuf< char_type, traits_type >::setg().
ios_base::openmode std::basic_filebuf< _CharT, _Traits >::_M_mode [protected] |
Place to stash in || out || in | out settings for current filebuf.
Definition at line 96 of file fstream.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_set_buffer().
char_type* std::basic_streambuf< _CharT, _Traits >::_M_out_beg [protected, inherited] |
Entry point for imbue().
- Parameters:
-
__loc The new locale.
- Returns:
- The previous locale.
Calls the derived imbue(__loc).
Definition at line 185 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::pbase(), and std::basic_streambuf< char_type, traits_type >::setp().
char_type* std::basic_streambuf< _CharT, _Traits >::_M_out_cur [protected, inherited] |
Entry point for imbue().
- Parameters:
-
__loc The new locale.
- Returns:
- The previous locale.
Calls the derived imbue(__loc).
Definition at line 186 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::pbump(), std::basic_streambuf< char_type, traits_type >::pptr(), and std::basic_streambuf< char_type, traits_type >::setp().
char_type* std::basic_streambuf< _CharT, _Traits >::_M_out_end [protected, inherited] |
Entry point for imbue().
- Parameters:
-
__loc The new locale.
- Returns:
- The previous locale.
Calls the derived imbue(__loc).
Definition at line 187 of file streambuf.
Referenced by std::basic_streambuf< char_type, traits_type >::epptr(), and std::basic_streambuf< char_type, traits_type >::setp().
char_type std::basic_filebuf< _CharT, _Traits >::_M_pback [protected] |
Necessary bits for putback buffer management.
- Note:
- pbacks of over one character are not currently supported.
Definition at line 139 of file fstream.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_create_pback().
char_type* std::basic_filebuf< _CharT, _Traits >::_M_pback_cur_save [protected] |
Necessary bits for putback buffer management.
- Note:
- pbacks of over one character are not currently supported.
Definition at line 140 of file fstream.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_create_pback(), and std::basic_filebuf< char_type, traits_type >::_M_destroy_pback().
char_type* std::basic_filebuf< _CharT, _Traits >::_M_pback_end_save [protected] |
Necessary bits for putback buffer management.
- Note:
- pbacks of over one character are not currently supported.
Definition at line 141 of file fstream.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_create_pback(), and std::basic_filebuf< char_type, traits_type >::_M_destroy_pback().
bool std::basic_filebuf< _CharT, _Traits >::_M_pback_init [protected] |
Necessary bits for putback buffer management.
- Note:
- pbacks of over one character are not currently supported.
Definition at line 142 of file fstream.
Referenced by std::basic_filebuf< char_type, traits_type >::_M_create_pback(), and std::basic_filebuf< char_type, traits_type >::_M_destroy_pback().
bool std::basic_filebuf< _CharT, _Traits >::_M_reading [protected] |
The documentation for this class was generated from the following files:
