Inheritance diagram for std::basic_filebuf< _CharT, _Traits >:

[legend]

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 ()

	basic_filebuf (const basic_filebuf &)=delete

	basic_filebuf (basic_filebuf &&)

virtual	~basic_filebuf ()

__filebuf_type *	close ()

locale	getloc () const

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)

basic_filebuf &	operator= (const basic_filebuf &)=delete

basic_filebuf &	operator= (basic_filebuf &&)

locale	pubimbue (const locale &__loc)

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 ()

void	swap (basic_filebuf &)


basic_streambuf *	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 ()

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 ()

void	swap (basic_streambuf &__sb)

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)


char_type *	eback () const

char_type *	gptr () const

char_type *	egptr () const


char_type *	pbase () const

char_type *	pptr () const

char_type *	epptr () const

Protected Attributes
char_type *	_M_buf

bool	_M_buf_allocated

locale	_M_buf_locale

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

char_type *	_M_in_beg

char_type *	_M_in_cur

char_type *	_M_in_end

__c_lock	_M_lock

ios_base::openmode	_M_mode

char_type *	_M_out_beg

char_type *	_M_out_cur

char_type *	_M_out_end

bool	_M_reading

__state_type	_M_state_beg

__state_type	_M_state_cur

__state_type	_M_state_last

bool	_M_writing


char_type	_M_pback

char_type *	_M_pback_cur_save

char_type *	_M_pback_end_save

bool	_M_pback_init

Friends
class	ios_base

Detailed Description

template<typename _CharT, typename _Traits>
class std::basic_filebuf< _CharT, _Traits >

The actual work of input and output (for files).

Template Parameters

_CharT	Type of character stream.
_Traits	Traits for character type, defaults to char_traits<_CharT>.

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.

Requirements on traits_type, specific to this class:

traits_type::pos_type must be fpos<traits_type::state_type>
traits_type::off_type must be streamoff
traits_type::state_type must be Assignable and DefaultConstructible,
traits_type::state_type() must be the initial state for codecvt.

Definition at line 72 of file fstream.

Constructor & Destructor Documentation

template<typename _CharT , typename _Traits >

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 80 of file fstream.tcc.

template<typename _CharT, typename _Traits>

virtual std::basic_filebuf< _CharT, _Traits >::~basic_filebuf ( )

inlinevirtual

The destructor closes the file first.

Definition at line 238 of file fstream.

Member Function Documentation

template<typename _CharT, typename _Traits>

void std::basic_filebuf< _CharT, _Traits >::_M_create_pback ( )

inlineprotected

Initializes pback buffers, and moves normal buffers to safety. Assumptions: _M_in_cur has already been moved back

Definition at line 191 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::pbackfail().

template<typename _CharT, typename _Traits>

void std::basic_filebuf< _CharT, _Traits >::_M_destroy_pback	(	)
throw	(
	)

inlineprotected

Deactivates pback buffer contents, and restores normal buffer. Assumptions: The pback buffer has only moved forward.

Definition at line 208 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::overflow(), std::basic_filebuf< _CharT, _Traits >::seekoff(), std::basic_filebuf< _CharT, _Traits >::seekpos(), std::basic_filebuf< _CharT, _Traits >::underflow(), and std::basic_filebuf< _CharT, _Traits >::xsgetn().

template<typename _CharT, typename _Traits>

void std::basic_filebuf< _CharT, _Traits >::_M_set_buffer ( streamsize __off )

inlineprotected

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.

Definition at line 422 of file fstream.

template<typename _CharT , typename _Traits >

basic_filebuf< _CharT, _Traits >::__filebuf_type * std::basic_filebuf< _CharT, _Traits >::close ( )

Closes the currently associated file.

Returns: this on 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 213 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_mode, std::basic_filebuf< _CharT, _Traits >::_M_pback_init, std::basic_filebuf< _CharT, _Traits >::_M_reading, std::basic_filebuf< _CharT, _Traits >::_M_set_buffer(), std::basic_filebuf< _CharT, _Traits >::is_open(), and std::basic_filebuf< _CharT, _Traits >::showmanyc().

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf(), and std::basic_filebuf< _CharT, _Traits >::open().

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::eback ( ) const

inlineprotectedinherited

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
gptr() returns the next pointer for the input sequence
egptr() returns the end pointer for the input sequence

Definition at line 482 of file streambuf.

Referenced by std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::pbackfail(), std::basic_filebuf< _CharT, _Traits >::seekpos(), std::basic_filebuf< _CharT, _Traits >::underflow(), and std::basic_filebuf< _CharT, _Traits >::xsgetn().

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::egptr ( ) const

inlineprotectedinherited

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
gptr() returns the next pointer for the input sequence
egptr() returns the end pointer for the input sequence

Definition at line 488 of file streambuf.

Referenced by std::ostreambuf_iterator< _CharT, _Traits >::failed(), std::basic_filebuf< _CharT, _Traits >::seekpos(), std::basic_filebuf< _CharT, _Traits >::showmanyc(), std::basic_filebuf< _CharT, _Traits >::underflow(), and std::basic_filebuf< _CharT, _Traits >::xsgetn().

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::epptr ( ) const

inlineprotectedinherited

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
pptr() returns the next pointer for the output sequence
epptr() returns the end pointer for the output sequence

Definition at line 535 of file streambuf.

Referenced by std::basic_filebuf< _CharT, _Traits >::xsputn().

template<typename _CharT, typename _Traits>

void std::basic_streambuf< _CharT, _Traits >::gbump ( int __n )

inlineprotectedinherited

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 498 of file streambuf.

Referenced by std::basic_filebuf< _CharT, _Traits >::pbackfail(), and std::basic_filebuf< _CharT, _Traits >::xsgetn().

template<typename _CharT, typename _Traits>

locale std::basic_streambuf< _CharT, _Traits >::getloc ( ) const

inlineinherited

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 226 of file streambuf.

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::gptr ( ) const

inlineprotectedinherited

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
gptr() returns the next pointer for the input sequence
egptr() returns the end pointer for the input sequence

Definition at line 485 of file streambuf.

Referenced by std::ostreambuf_iterator< _CharT, _Traits >::failed(), std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::pbackfail(), std::basic_filebuf< _CharT, _Traits >::seekpos(), std::basic_filebuf< _CharT, _Traits >::showmanyc(), std::basic_filebuf< _CharT, _Traits >::underflow(), and std::basic_filebuf< _CharT, _Traits >::xsgetn().

template<typename _CharT , typename _Traits >

void std::basic_filebuf< _CharT, _Traits >::imbue ( const locale & __loc )

protectedvirtual

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 997 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_ext_buf, std::basic_filebuf< _CharT, _Traits >::_M_ext_next, std::basic_filebuf< _CharT, _Traits >::_M_mode, std::basic_filebuf< _CharT, _Traits >::_M_reading, std::basic_filebuf< _CharT, _Traits >::_M_set_buffer(), std::ios_base::cur, std::basic_streambuf< _CharT, _Traits >::eback(), std::basic_streambuf< _CharT, _Traits >::gptr(), std::basic_filebuf< _CharT, _Traits >::is_open(), and std::basic_filebuf< _CharT, _Traits >::seekoff().

Referenced by std::basic_filebuf< _CharT, _Traits >::sync().

template<typename _CharT, typename _Traits>

streamsize std::basic_streambuf< _CharT, _Traits >::in_avail ( )

inlineinherited

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().

Definition at line 284 of file streambuf.

template<typename _CharT, typename _Traits>

bool std::basic_filebuf< _CharT, _Traits >::is_open	(	)	const
throw	(
	)

inline

Returns true if the external file is open.

Definition at line 252 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::close(), std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::open(), std::basic_filebuf< _CharT, _Traits >::seekoff(), std::basic_filebuf< _CharT, _Traits >::seekpos(), std::basic_filebuf< _CharT, _Traits >::setbuf(), std::basic_filebuf< _CharT, _Traits >::showmanyc(), and __gnu_cxx::stdio_filebuf< _CharT, _Traits >::stdio_filebuf().

template<typename _CharT , typename _Traits >

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: this on 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.

+---------------------------------------------------------+
| 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 179 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_mode, std::basic_filebuf< _CharT, _Traits >::_M_reading, std::basic_filebuf< _CharT, _Traits >::_M_set_buffer(), std::ios_base::ate, std::basic_filebuf< _CharT, _Traits >::close(), std::ios_base::end, std::basic_filebuf< _CharT, _Traits >::is_open(), and std::basic_filebuf< _CharT, _Traits >::seekoff().

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf().

template<typename _CharT, typename _Traits>

__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: this on success, NULL on failure

Definition at line 307 of file fstream.

template<typename _CharT , typename _Traits >

basic_filebuf< _CharT, _Traits >::int_type std::basic_filebuf< _CharT, _Traits >::overflow ( int_type __c = _Traits::eof() )

protectedvirtual

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 507 of file fstream.tcc.

Referenced by std::basic_filebuf< _CharT, _Traits >::pbackfail(), std::basic_filebuf< _CharT, _Traits >::seekpos(), std::basic_filebuf< _CharT, _Traits >::sync(), std::basic_filebuf< _CharT, _Traits >::underflow(), and std::basic_filebuf< _CharT, _Traits >::xsgetn().

template<typename _CharT , typename _Traits >

basic_filebuf< _CharT, _Traits >::int_type std::basic_filebuf< _CharT, _Traits >::pbackfail ( int_type __c = _Traits::eof() )

protectedvirtual

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(), and pptr() are the same as for underflow().

Note: Base class version does nothing, returns eof().

Reimplemented from std::basic_streambuf< _CharT, _Traits >.

Definition at line 448 of file fstream.tcc.

Referenced by std::basic_filebuf< _CharT, _Traits >::underflow().

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::pbase ( ) const

inlineprotectedinherited

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
pptr() returns the next pointer for the output sequence
epptr() returns the end pointer for the output sequence

Definition at line 529 of file streambuf.

Referenced by std::basic_filebuf< _CharT, _Traits >::overflow(), std::basic_filebuf< _CharT, _Traits >::seekoff(), std::basic_filebuf< _CharT, _Traits >::seekpos(), std::basic_filebuf< _CharT, _Traits >::sync(), and std::basic_filebuf< _CharT, _Traits >::xsputn().

template<typename _CharT, typename _Traits>

void std::basic_streambuf< _CharT, _Traits >::pbump ( int __n )

inlineprotectedinherited

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 545 of file streambuf.

Referenced by std::basic_filebuf< _CharT, _Traits >::overflow().

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::pptr ( ) const

inlineprotectedinherited

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
pptr() returns the next pointer for the output sequence
epptr() returns the end pointer for the output sequence

Definition at line 532 of file streambuf.

Referenced by std::basic_filebuf< _CharT, _Traits >::overflow(), std::basic_filebuf< _CharT, _Traits >::seekoff(), std::basic_filebuf< _CharT, _Traits >::seekpos(), std::basic_filebuf< _CharT, _Traits >::sync(), and std::basic_filebuf< _CharT, _Traits >::xsputn().

template<typename _CharT, typename _Traits>

locale std::basic_streambuf< _CharT, _Traits >::pubimbue ( const locale & __loc )

inlineinherited

Entry point for imbue().

Parameters

__loc The new locale.

Returns: The previous locale.

Calls the derived imbue(__loc).

Definition at line 209 of file streambuf.

template<typename _CharT, typename _Traits>

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`
	)

inlineinherited

Alters the stream position.

Parameters

__off	Offset.
__way	Value for ios_base::seekdir.
__mode	Value for ios_base::openmode.

Calls virtual seekoff function.

Definition at line 251 of file streambuf.

template<typename _CharT, typename _Traits>

pos_type std::basic_streambuf< _CharT, _Traits >::pubseekpos	(	pos_type	__sp,
		ios_base::openmode	__mode = `ios_base::in \| ios_base::out`
	)

inlineinherited

Alters the stream position.

Parameters

__sp	Position
__mode	Value for ios_base::openmode.

Calls virtual seekpos function.

Definition at line 263 of file streambuf.

template<typename _CharT, typename _Traits>

basic_streambuf* std::basic_streambuf< _CharT, _Traits >::pubsetbuf	(	char_type *	__s,
		streamsize	__n
	)

inlineinherited

Entry points for derived buffer functions.

The public versions of pubfoo dispatch to the protected derived foo member functions, passing the arguments (if any) and returning the result unchanged.

Definition at line 239 of file streambuf.

template<typename _CharT, typename _Traits>

int std::basic_streambuf< _CharT, _Traits >::pubsync ( )

inlineinherited

Calls virtual sync function.

Definition at line 271 of file streambuf.

Referenced by std::basic_istream< _CharT, _Traits >::sync().

template<typename _CharT, typename _Traits>

int_type std::basic_streambuf< _CharT, _Traits >::sbumpc ( )

inlineinherited

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 316 of file streambuf.

Referenced by std::basic_istream< _CharT, _Traits >::getline(), std::basic_istream< _CharT, _Traits >::ignore(), and std::istreambuf_iterator< _CharT, _Traits >::operator++().

template<typename _CharT , typename _Traits >

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`
	)

protectedvirtual

Alters the stream positions.

Each derived class provides its own appropriate behavior.

Note: Base class version does nothing, returns a pos_type that represents an invalid stream position.

Reimplemented from std::basic_streambuf< _CharT, _Traits >.

Definition at line 800 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_destroy_pback(), std::basic_filebuf< _CharT, _Traits >::_M_reading, std::ios_base::cur, std::basic_filebuf< _CharT, _Traits >::is_open(), std::basic_streambuf< _CharT, _Traits >::pbase(), std::basic_streambuf< _CharT, _Traits >::pptr(), and std::basic_filebuf< _CharT, _Traits >::seekpos().

Referenced by std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::open(), std::basic_filebuf< _CharT, _Traits >::pbackfail(), and std::basic_filebuf< _CharT, _Traits >::setbuf().

template<typename _CharT , typename _Traits >

basic_filebuf< _CharT, _Traits >::pos_type std::basic_filebuf< _CharT, _Traits >::seekpos	(	pos_type	,
		ios_base::openmode	= `ios_base::in \| ios_base::out`
	)

protectedvirtual

Alters the stream positions.

Each derived class provides its own appropriate behavior.

Note: Base class version does nothing, returns a pos_type that represents an invalid stream position.

Reimplemented from std::basic_streambuf< _CharT, _Traits >.

Definition at line 860 of file fstream.tcc.

Referenced by std::basic_filebuf< _CharT, _Traits >::seekoff().

template<typename _CharT , typename _Traits >

basic_filebuf< _CharT, _Traits >::__streambuf_type * std::basic_filebuf< _CharT, _Traits >::setbuf	(	char_type *	__s,
		streamsize	__n
	)

protectedvirtual

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 https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering for more.

Reimplemented from std::basic_streambuf< _CharT, _Traits >.

Definition at line 771 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_buf, std::basic_filebuf< _CharT, _Traits >::_M_buf_size, std::basic_filebuf< _CharT, _Traits >::is_open(), and std::basic_filebuf< _CharT, _Traits >::seekoff().

Referenced by std::basic_filebuf< _CharT, _Traits >::xsputn().

template<typename _CharT, typename _Traits>

void std::basic_streambuf< _CharT, _Traits >::setg	(	char_type *	__gbeg,
		char_type *	__gnext,
		char_type *	__gend
	)

inlineprotectedinherited

Setting the three read area pointers.

Parameters

__gbeg	A pointer.
__gnext	A pointer.
__gend	A pointer.

Postcondition: __gbeg == eback(), __gnext == gptr(), and __gend == egptr()

Definition at line 509 of file streambuf.

Referenced by std::basic_filebuf< _CharT, _Traits >::xsgetn().

template<typename _CharT, typename _Traits>

void std::basic_streambuf< _CharT, _Traits >::setp	(	char_type *	__pbeg,
		char_type *	__pend
	)

inlineprotectedinherited

Setting the three write area pointers.

Parameters

__pbeg	A pointer.
__pend	A pointer.

Postcondition: __pbeg == pbase(), __pbeg == pptr(), and __pend == epptr()

Definition at line 555 of file streambuf.

template<typename _CharT, typename _Traits>

int_type std::basic_streambuf< _CharT, _Traits >::sgetc ( )

inlineinherited

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 338 of file streambuf.

Referenced by std::istreambuf_iterator< _CharT, _Traits >::equal(), std::ostreambuf_iterator< _CharT, _Traits >::failed(), 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< _CharT, _Traits >::xsputn().

template<typename _CharT, typename _Traits>

streamsize std::basic_streambuf< _CharT, _Traits >::sgetn	(	char_type *	__s,
		streamsize	__n
	)

inlineinherited

Entry point for xsgetn.

Parameters

__s	A buffer area.
__n	A count.

Returns xsgetn(__s,__n). The effect is to fill __s[0] through __s[__n-1] with characters from the input sequence, if possible.

Definition at line 357 of file streambuf.

template<typename _CharT , typename _Traits >

streamsize std::basic_filebuf< _CharT, _Traits >::showmanyc ( )

protectedvirtual

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 showmanyc are es-how-many-see, not show-manic.

Reimplemented from std::basic_streambuf< _CharT, _Traits >.

Definition at line 263 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_mode, std::ios_base::binary, std::basic_streambuf< _CharT, _Traits >::egptr(), std::basic_streambuf< _CharT, _Traits >::gptr(), std::ios_base::in, std::basic_filebuf< _CharT, _Traits >::is_open(), and std::basic_filebuf< _CharT, _Traits >::underflow().

Referenced by std::basic_filebuf< _CharT, _Traits >::close().

template<typename _CharT, typename _Traits>

int_type std::basic_streambuf< _CharT, _Traits >::snextc ( )

inlineinherited

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 298 of file streambuf.

Referenced by std::ostreambuf_iterator< _CharT, _Traits >::failed(), 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< _CharT, _Traits >::xsputn().

template<typename _CharT, typename _Traits>

int_type std::basic_streambuf< _CharT, _Traits >::sputbackc ( char_type __c )

inlineinherited

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 372 of file streambuf.

Referenced by std::basic_istream< _CharT, _Traits >::putback().

template<typename _CharT, typename _Traits>

int_type std::basic_streambuf< _CharT, _Traits >::sputc ( char_type __c )

inlineinherited

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 424 of file streambuf.

Referenced by std::basic_istream< _CharT, _Traits >::get(), std::ostreambuf_iterator< _CharT, _Traits >::operator=(), and std::basic_streambuf< _CharT, _Traits >::xsputn().

template<typename _CharT, typename _Traits>

streamsize std::basic_streambuf< _CharT, _Traits >::sputn	(	const char_type *	__s,
		streamsize	__n
	)

inlineinherited

Entry point for all single-character output functions.

Parameters

__s	A buffer read area.
__n	A count.

One of two public output functions.

Returns xsputn(__s,__n). The effect is to write __s[0] through __s[__n-1] to the output sequence, if possible.

Definition at line 450 of file streambuf.

Referenced by std::ostreambuf_iterator< _CharT, _Traits >::failed().

template<typename _CharT, typename _Traits>

int_type std::basic_streambuf< _CharT, _Traits >::sungetc ( )

inlineinherited

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 397 of file streambuf.

Referenced by std::basic_istream< _CharT, _Traits >::unget().

template<typename _CharT , typename _Traits >

int std::basic_filebuf< _CharT, _Traits >::sync ( )

protectedvirtual

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 980 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::overflow(), std::basic_streambuf< _CharT, _Traits >::pbase(), and std::basic_streambuf< _CharT, _Traits >::pptr().

Referenced by std::basic_filebuf< _CharT, _Traits >::seekpos().

template<typename _CharT, typename _Traits>

virtual int_type std::basic_streambuf< _CharT, _Traits >::uflow ( )

inlineprotectedvirtualinherited

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 700 of file streambuf.

template<typename _CharT , typename _Traits >

basic_filebuf< _CharT, _Traits >::int_type std::basic_filebuf< _CharT, _Traits >::underflow ( )

protectedvirtual

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 https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html

Note: Base class version does nothing, returns eof().

Reimplemented from std::basic_streambuf< _CharT, _Traits >.

Definition at line 289 of file fstream.tcc.

Referenced by std::basic_filebuf< _CharT, _Traits >::pbackfail(), and std::basic_filebuf< _CharT, _Traits >::showmanyc().

template<typename _CharT , typename _Traits >

streamsize std::basic_filebuf< _CharT, _Traits >::xsgetn	(	char_type *	__s,
		streamsize	__n
	)

protectedvirtual

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 635 of file fstream.tcc.

Referenced by std::basic_filebuf< _CharT, _Traits >::overflow().

template<typename _CharT , typename _Traits >

streamsize std::basic_filebuf< _CharT, _Traits >::xsputn	(	const char_type *	__s,
		streamsize	__n
	)

protectedvirtual

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 723 of file fstream.tcc.

Referenced by std::basic_filebuf< _CharT, _Traits >::overflow(), and std::basic_filebuf< _CharT, _Traits >::xsgetn().

Member Data Documentation

template<typename _CharT, typename _Traits>

char_type* std::basic_filebuf< _CharT, _Traits >::_M_buf

protected

Pointer to the beginning of internal buffer.

Definition at line 128 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf(), and std::basic_filebuf< _CharT, _Traits >::setbuf().

template<typename _CharT, typename _Traits>

locale std::basic_streambuf< _CharT, _Traits >::_M_buf_locale

protectedinherited

Current locale setting.

Definition at line 192 of file streambuf.

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf().

template<typename _CharT, typename _Traits>

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 135 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf(), std::basic_filebuf< _CharT, _Traits >::overflow(), std::basic_filebuf< _CharT, _Traits >::setbuf(), __gnu_cxx::stdio_filebuf< _CharT, _Traits >::stdio_filebuf(), std::basic_filebuf< _CharT, _Traits >::underflow(), std::basic_filebuf< _CharT, _Traits >::xsgetn(), and std::basic_filebuf< _CharT, _Traits >::xsputn().

template<typename _CharT, typename _Traits>

char* std::basic_filebuf< _CharT, _Traits >::_M_ext_buf

protected

Buffer for external characters. Used for input when codecvt::always_noconv() == false. When valid, this corresponds to eback().

Definition at line 170 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf(), std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::seekpos(), and std::basic_filebuf< _CharT, _Traits >::underflow().

template<typename _CharT, typename _Traits>

streamsize std::basic_filebuf< _CharT, _Traits >::_M_ext_buf_size

protected

Size of buffer held by _M_ext_buf.

Definition at line 175 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf(), and std::basic_filebuf< _CharT, _Traits >::underflow().

template<typename _CharT, typename _Traits>

const char* std::basic_filebuf< _CharT, _Traits >::_M_ext_next

protected

Pointers into the buffer held by _M_ext_buf that delimit a subsequence of bytes that have been read but not yet converted. When valid, _M_ext_next corresponds to egptr().

Definition at line 182 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf(), std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::seekpos(), and std::basic_filebuf< _CharT, _Traits >::underflow().

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::_M_in_beg

protectedinherited

Start of get area.

Definition at line 184 of file streambuf.

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::_M_in_cur

protectedinherited

Current read area.

Definition at line 185 of file streambuf.

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::_M_in_end

protectedinherited

End of get area.

Definition at line 186 of file streambuf.

template<typename _CharT, typename _Traits>

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 113 of file fstream.

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::_M_out_beg

protectedinherited

Start of put area.

Definition at line 187 of file streambuf.

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::_M_out_cur

protectedinherited

Current put area.

Definition at line 188 of file streambuf.

template<typename _CharT, typename _Traits>

char_type* std::basic_streambuf< _CharT, _Traits >::_M_out_end

protectedinherited

End of put area.

Definition at line 189 of file streambuf.

template<typename _CharT, typename _Traits>

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 156 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf().

template<typename _CharT, typename _Traits>

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 157 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf().

template<typename _CharT, typename _Traits>

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 158 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf().

template<typename _CharT, typename _Traits>

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 159 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::basic_filebuf(), std::basic_filebuf< _CharT, _Traits >::close(), std::basic_filebuf< _CharT, _Traits >::pbackfail(), and std::basic_filebuf< _CharT, _Traits >::xsgetn().

template<typename _CharT, typename _Traits>

bool std::basic_filebuf< _CharT, _Traits >::_M_reading

protected

_M_reading == false && _M_writing == false for uncommitted mode; _M_reading == true for read mode; _M_writing == true for write mode;

NB: _M_reading == true && _M_writing == true is unused.

Definition at line 147 of file fstream.

The documentation for this class was generated from the following files:

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

template<typename _CharT, typename _Traits> class std::basic_filebuf< _CharT, _Traits >

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<typename _CharT, typename _Traits>
class std::basic_filebuf< _CharT, _Traits >