std::basic_filebuf

std::basic_filebuf< _CharT, _Traits > Class Template Reference

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

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

std::basic_streambuf< _CharT, _Traits > __gnu_cxx::stdio_filebuf< _CharT, _Traits > List of all members.

Public Types

typedef _CharT char_type
typedef _Traits traits_type
typedef traits_type::int_type int_type
typedef traits_type::pos_type pos_type
typedef traits_type::off_type off_type
typedef basic_streambuf< char_type,
traits_type > 		__streambuf_type
typedef basic_filebuf< char_type,
traits_type > 		__filebuf_type
typedef __basic_file< char > __file_type
typedef traits_type::state_type __state_type
typedef codecvt< char_type,
char, __state_type > 		__codecvt_type

Public Member Functions

 basic_filebuf ()
 Does not open any files.
virtual ~basic_filebuf ()
 The destructor closes the file first.
bool is_open () const throw ()
 Returns true if the external file is open.
__filebuf_type * open (const char *__s, ios_base::openmode __mode)
 Opens an external file.
__filebuf_type * close () throw ()
 Closes the currently associated file.

Protected Member Functions

void _M_create_pback ()
void _M_destroy_pback () throw ()
void _M_allocate_internal_buffer ()
void _M_destroy_internal_buffer () throw ()
virtual streamsize showmanyc ()
 Investigating the data available.
virtual int_type underflow ()
 Fetches more data from the controlled sequence.
virtual int_type pbackfail (int_type __c=_Traits::eof())
 Tries to back up the input sequence.
virtual int_type overflow (int_type __c=_Traits::eof())
 Consumes data from the buffer; writes to the controlled sequence.
bool _M_convert_to_external (char_type *, streamsize)
virtual __streambuf_type * setbuf (char_type *__s, streamsize __n)
 Manipulates the buffer.
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)
pos_type _M_seek (off_type __off, ios_base::seekdir __way, __state_type __state)
virtual int sync ()
 Synchronizes the buffer arrays with the controlled sequences.
virtual void imbue (const locale &__loc)
 Changes translations.
virtual streamsize xsgetn (char_type *__s, streamsize __n)
 Multiple character extraction.
virtual streamsize xsputn (const char_type *__s, streamsize __n)
 Multiple character insertion.
bool _M_terminate_output ()
void _M_set_buffer (streamsize __off)

Protected Attributes

__c_lock _M_lock
__file_type _M_file
ios_base::openmode _M_mode
__state_type _M_state_beg
__state_type _M_state_cur
__state_type _M_state_last
char_type * _M_buf
size_t _M_buf_size
bool _M_buf_allocated
bool _M_reading
bool _M_writing
const __codecvt_type * _M_codecvt
char * _M_ext_buf
streamsize _M_ext_buf_size
const char * _M_ext_next
char * _M_ext_end
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).

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 sematics are described in terms of similar behavior in the Standard C Library's FILE streams.

Definition at line 68 of file fstream.

Member Typedef Documentation

template<typename _CharT, typename _Traits>
typedef codecvt<char_type, char, __state_type> std::basic_filebuf< _CharT, _Traits >::__codecvt_type

Definition at line 82 of file fstream.

template<typename _CharT, typename _Traits>
typedef __basic_file<char> std::basic_filebuf< _CharT, _Traits >::__file_type

Definition at line 80 of file fstream.

template<typename _CharT, typename _Traits>
typedef basic_filebuf<char_type, traits_type> std::basic_filebuf< _CharT, _Traits >::__filebuf_type

Definition at line 79 of file fstream.

template<typename _CharT, typename _Traits>
typedef traits_type::state_type std::basic_filebuf< _CharT, _Traits >::__state_type

Definition at line 81 of file fstream.

template<typename _CharT, typename _Traits>
typedef basic_streambuf<char_type, traits_type> std::basic_filebuf< _CharT, _Traits >::__streambuf_type

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

Definition at line 78 of file fstream.

template<typename _CharT, typename _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 >.

Definition at line 72 of file fstream.

template<typename _CharT, typename _Traits>
typedef traits_type::int_type std::basic_filebuf< _CharT, _Traits >::int_type

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

Reimplemented in __gnu_cxx::stdio_filebuf< _CharT, _Traits >.

Definition at line 74 of file fstream.

template<typename _CharT, typename _Traits>
typedef traits_type::off_type std::basic_filebuf< _CharT, _Traits >::off_type

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

Reimplemented in __gnu_cxx::stdio_filebuf< _CharT, _Traits >.

Definition at line 76 of file fstream.

template<typename _CharT, typename _Traits>
typedef traits_type::pos_type std::basic_filebuf< _CharT, _Traits >::pos_type

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

Reimplemented in __gnu_cxx::stdio_filebuf< _CharT, _Traits >.

Definition at line 75 of file fstream.

template<typename _CharT, typename _Traits>
typedef _Traits std::basic_filebuf< _CharT, _Traits >::traits_type

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

Reimplemented in __gnu_cxx::stdio_filebuf< _CharT, _Traits >.

Definition at line 73 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 81 of file fstream.tcc.

References std::basic_streambuf< _CharT, _Traits >::_M_buf_locale, and std::basic_filebuf< _CharT, _Traits >::_M_codecvt.

template<typename _CharT, typename _Traits>
virtual std::basic_filebuf< _CharT, _Traits >::~basic_filebuf (  )  [inline, virtual]

The destructor closes the file first.

Definition at line 239 of file fstream.

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

Member Function Documentation

template<typename _CharT, typename _Traits>
void std::basic_filebuf< _CharT, _Traits >::_M_allocate_internal_buffer (  )  [protected]

Definition at line 50 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_buf, std::basic_filebuf< _CharT, _Traits >::_M_buf_allocated, and std::basic_filebuf< _CharT, _Traits >::_M_buf_size.

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

template<typename _CharT, typename _Traits>
bool std::basic_filebuf< _CharT, _Traits >::_M_convert_to_external ( char_type *  ,
streamsize   
) [protected]

Definition at line 448 of file fstream.tcc.

References std::__check_facet(), __N, std::__throw_ios_failure(), std::basic_filebuf< _CharT, _Traits >::_M_codecvt, std::basic_filebuf< _CharT, _Traits >::_M_file, std::basic_filebuf< _CharT, _Traits >::_M_state_cur, codecvt_base::error, __codecvt_abstract_base< _InternT, _ExternT, _StateT >::max_length(), codecvt_base::noconv, codecvt_base::ok, __codecvt_abstract_base< _InternT, _ExternT, _StateT >::out(), codecvt_base::partial, std::basic_streambuf< _CharT, _Traits >::pptr(), and std::__basic_file< char >::xsputn().

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

template<typename _CharT, typename _Traits>
void std::basic_filebuf< _CharT, _Traits >::_M_create_pback (  )  [inline, protected]

Definition at line 195 of file fstream.

References std::basic_filebuf< _CharT, _Traits >::_M_pback, std::basic_filebuf< _CharT, _Traits >::_M_pback_cur_save, std::basic_filebuf< _CharT, _Traits >::_M_pback_end_save, std::basic_filebuf< _CharT, _Traits >::_M_pback_init, std::basic_streambuf< _CharT, _Traits >::egptr(), std::basic_streambuf< _CharT, _Traits >::gptr(), and std::basic_streambuf< _CharT, _Traits >::setg().

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

template<typename _CharT, typename _Traits>
void std::basic_filebuf< _CharT, _Traits >::_M_destroy_internal_buffer (  )  throw () [protected]

Definition at line 64 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_buf, std::basic_filebuf< _CharT, _Traits >::_M_buf_allocated, std::basic_filebuf< _CharT, _Traits >::_M_ext_buf, std::basic_filebuf< _CharT, _Traits >::_M_ext_buf_size, std::basic_filebuf< _CharT, _Traits >::_M_ext_end, and std::basic_filebuf< _CharT, _Traits >::_M_ext_next.

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

template<typename _CharT, typename _Traits>
void std::basic_filebuf< _CharT, _Traits >::_M_destroy_pback (  )  throw () [inline, protected]

Definition at line 214 of file fstream.

References std::basic_filebuf< _CharT, _Traits >::_M_buf, std::basic_filebuf< _CharT, _Traits >::_M_pback_cur_save, std::basic_filebuf< _CharT, _Traits >::_M_pback_end_save, std::basic_filebuf< _CharT, _Traits >::_M_pback_init, std::basic_streambuf< _CharT, _Traits >::eback(), std::basic_streambuf< _CharT, _Traits >::gptr(), and std::basic_streambuf< _CharT, _Traits >::setg().

Referenced by 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>
basic_filebuf< _CharT, _Traits >::pos_type std::basic_filebuf< _CharT, _Traits >::_M_seek ( off_type  __off,
ios_base::seekdir  __way,
__state_type  __state 
) [protected]

Definition at line 736 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_ext_buf, std::basic_filebuf< _CharT, _Traits >::_M_ext_end, std::basic_filebuf< _CharT, _Traits >::_M_ext_next, std::basic_filebuf< _CharT, _Traits >::_M_file, std::basic_filebuf< _CharT, _Traits >::_M_reading, std::basic_filebuf< _CharT, _Traits >::_M_set_buffer(), std::basic_filebuf< _CharT, _Traits >::_M_state_cur, std::basic_filebuf< _CharT, _Traits >::_M_terminate_output(), std::basic_filebuf< _CharT, _Traits >::_M_writing, and std::__basic_file< char >::seekoff().

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

template<typename _CharT, typename _Traits>
void std::basic_filebuf< _CharT, _Traits >::_M_set_buffer ( streamsize  __off  )  [inline, protected]

Definition at line 375 of file fstream.

References std::basic_filebuf< _CharT, _Traits >::_M_buf, std::basic_filebuf< _CharT, _Traits >::_M_buf_size, std::basic_filebuf< _CharT, _Traits >::_M_mode, std::ios_base::in, std::ios_base::out, std::basic_streambuf< _CharT, _Traits >::setg(), and std::basic_streambuf< _CharT, _Traits >::setp().

Referenced by std::basic_filebuf< _CharT, _Traits >::_M_seek(), std::basic_filebuf< _CharT, _Traits >::close(), std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::open(), std::basic_filebuf< _CharT, _Traits >::overflow(), __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>
bool std::basic_filebuf< _CharT, _Traits >::_M_terminate_output (  )  [protected]

Definition at line 759 of file fstream.tcc.

References std::__check_facet(), std::basic_filebuf< _CharT, _Traits >::_M_codecvt, std::basic_filebuf< _CharT, _Traits >::_M_file, std::basic_filebuf< _CharT, _Traits >::_M_state_cur, std::basic_filebuf< _CharT, _Traits >::_M_writing, codecvt_base::error, codecvt_base::ok, std::basic_filebuf< _CharT, _Traits >::overflow(), codecvt_base::partial, std::basic_streambuf< _CharT, _Traits >::pptr(), __codecvt_abstract_base< _InternT, _ExternT, _StateT >::unshift(), and std::__basic_file< char >::xsputn().

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

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

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 130 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_destroy_internal_buffer(), std::basic_filebuf< _CharT, _Traits >::_M_file, 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 >::_M_state_beg, std::basic_filebuf< _CharT, _Traits >::_M_state_cur, std::basic_filebuf< _CharT, _Traits >::_M_state_last, std::basic_filebuf< _CharT, _Traits >::_M_terminate_output(), std::basic_filebuf< _CharT, _Traits >::_M_writing, and std::__basic_file< char >::close().

Referenced by std::basic_fstream< _CharT, _Traits >::close(), std::basic_ofstream< _CharT, _Traits >::close(), std::basic_ifstream< _CharT, _Traits >::close(), and std::basic_filebuf< _CharT, _Traits >::~basic_filebuf().

template<typename _CharT, typename _Traits>
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 837 of file fstream.tcc.

References std::__check_facet(), std::basic_filebuf< _CharT, _Traits >::_M_codecvt, std::basic_filebuf< _CharT, _Traits >::_M_ext_buf, std::basic_filebuf< _CharT, _Traits >::_M_ext_end, 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::basic_filebuf< _CharT, _Traits >::_M_state_beg, std::basic_filebuf< _CharT, _Traits >::_M_state_cur, std::basic_filebuf< _CharT, _Traits >::_M_state_last, std::basic_filebuf< _CharT, _Traits >::_M_terminate_output(), std::basic_filebuf< _CharT, _Traits >::_M_writing, std::ios_base::cur, std::basic_streambuf< _CharT, _Traits >::eback(), and std::basic_filebuf< _CharT, _Traits >::seekoff().

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 247 of file fstream.

References std::basic_filebuf< _CharT, _Traits >::_M_file, and std::__basic_file< char >::is_open().

Referenced by std::basic_fstream< _CharT, _Traits >::is_open(), std::basic_ofstream< _CharT, _Traits >::is_open(), and std::basic_ifstream< _CharT, _Traits >::is_open().

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.

[Table 92 gives the relation between openmode combinations and the equivalent fopen() flags, but the table has not been copied yet.]

Definition at line 96 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_allocate_internal_buffer(), std::basic_filebuf< _CharT, _Traits >::_M_file, std::basic_filebuf< _CharT, _Traits >::_M_mode, std::basic_filebuf< _CharT, _Traits >::_M_reading, std::basic_filebuf< _CharT, _Traits >::_M_set_buffer(), std::basic_filebuf< _CharT, _Traits >::_M_state_beg, std::basic_filebuf< _CharT, _Traits >::_M_state_cur, std::basic_filebuf< _CharT, _Traits >::_M_state_last, std::basic_filebuf< _CharT, _Traits >::_M_writing, std::ios_base::ate, std::ios_base::end, and std::__basic_file< char >::open().

Referenced by std::basic_fstream< _CharT, _Traits >::open(), std::basic_ofstream< _CharT, _Traits >::open(), and std::basic_ifstream< _CharT, _Traits >::open().

template<typename _CharT, typename _Traits>
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 definiton 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 392 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_buf_size, std::basic_filebuf< _CharT, _Traits >::_M_convert_to_external(), std::basic_filebuf< _CharT, _Traits >::_M_mode, std::basic_filebuf< _CharT, _Traits >::_M_reading, std::basic_filebuf< _CharT, _Traits >::_M_set_buffer(), std::basic_filebuf< _CharT, _Traits >::_M_writing, std::ios_base::out, std::basic_streambuf< _CharT, _Traits >::pbase(), std::basic_streambuf< _CharT, _Traits >::pbump(), and std::basic_streambuf< _CharT, _Traits >::pptr().

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

template<typename _CharT, typename _Traits>
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(), 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 340 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_create_pback(), 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_writing, std::ios_base::cur, std::basic_streambuf< _CharT, _Traits >::gptr(), and std::ios_base::in.

template<typename _CharT, typename _Traits>
basic_filebuf< _CharT, _Traits >::pos_type std::basic_filebuf< _CharT, _Traits >::seekoff ( off_type  __off,
ios_base::seekdir  __way,
ios_base::openmode  __mode = ios_base::in|ios_base::out 
) [protected, virtual]

Definition at line 668 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_codecvt, std::basic_filebuf< _CharT, _Traits >::_M_destroy_pback(), std::basic_filebuf< _CharT, _Traits >::_M_ext_buf, std::basic_filebuf< _CharT, _Traits >::_M_ext_end, std::basic_filebuf< _CharT, _Traits >::_M_ext_next, std::basic_filebuf< _CharT, _Traits >::_M_reading, std::basic_filebuf< _CharT, _Traits >::_M_seek(), std::basic_filebuf< _CharT, _Traits >::_M_state_beg, std::basic_filebuf< _CharT, _Traits >::_M_state_last, __codecvt_abstract_base< _InternT, _ExternT, _StateT >::always_noconv(), std::ios_base::cur, std::basic_streambuf< _CharT, _Traits >::eback(), std::basic_streambuf< _CharT, _Traits >::egptr(), __codecvt_abstract_base< _InternT, _ExternT, _StateT >::encoding(), and __codecvt_abstract_base< _InternT, _ExternT, _StateT >::length().

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

template<typename _CharT, typename _Traits>
basic_filebuf< _CharT, _Traits >::pos_type std::basic_filebuf< _CharT, _Traits >::seekpos ( pos_type  __pos,
ios_base::openmode  __mode = ios_base::in|ios_base::out 
) [protected, virtual]

Definition at line 721 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_destroy_pback(), std::basic_filebuf< _CharT, _Traits >::_M_seek(), and std::ios_base::beg.

template<typename _CharT, typename _Traits>
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++/27_io/howto.html#2 for more.

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

Definition at line 641 of file fstream.tcc.

References std::basic_filebuf< _CharT, _Traits >::_M_buf, and std::basic_filebuf< _CharT, _Traits >::_M_buf_size.

template<typename _CharT, typename _Traits>
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 showmanyc are "es-how-many-see", not "show-manic".

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

Definition at line 165 of file fstream.tcc.

References std::__check_facet(), std::basic_filebuf< _CharT, _Traits >::_M_codecvt, std::basic_filebuf< _CharT, _Traits >::_M_file, std::basic_filebuf< _CharT, _Traits >::_M_mode, std::ios_base::binary, std::basic_streambuf< _CharT, _Traits >::gptr(), std::ios_base::in, and std::__basic_file< char >::showmanyc().

template<typename _CharT, typename _Traits>
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 820 of file fstream.tcc.

References std::basic_streambuf< _CharT, _Traits >::pptr().

template<typename _CharT, typename _Traits>
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 definiton 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++/27_io/howto.html#6

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

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

Definition at line 191 of file fstream.tcc.

References std::__check_facet(), __N, std::__throw_ios_failure(), std::basic_filebuf< _CharT, _Traits >::_M_buf_size, std::basic_filebuf< _CharT, _Traits >::_M_codecvt, std::basic_filebuf< _CharT, _Traits >::_M_destroy_pback(), std::basic_filebuf< _CharT, _Traits >::_M_ext_buf, std::basic_filebuf< _CharT, _Traits >::_M_ext_buf_size, std::basic_filebuf< _CharT, _Traits >::_M_ext_end, std::basic_filebuf< _CharT, _Traits >::_M_ext_next, std::basic_filebuf< _CharT, _Traits >::_M_file, std::basic_filebuf< _CharT, _Traits >::_M_mode, std::basic_filebuf< _CharT, _Traits >::_M_reading, std::basic_filebuf< _CharT, _Traits >::_M_set_buffer(), std::basic_filebuf< _CharT, _Traits >::_M_state_cur, std::basic_filebuf< _CharT, _Traits >::_M_state_last, std::basic_filebuf< _CharT, _Traits >::_M_writing, std::copy(), std::basic_streambuf< _CharT, _Traits >::eback(), std::basic_streambuf< _CharT, _Traits >::egptr(), __codecvt_abstract_base< _InternT, _ExternT, _StateT >::encoding(), codecvt_base::error, __codecvt_abstract_base< _InternT, _ExternT, _StateT >::in(), std::ios_base::in, __codecvt_abstract_base< _InternT, _ExternT, _StateT >::max_length(), std::min(), codecvt_base::noconv, codecvt_base::ok, codecvt_base::partial, and std::__basic_file< char >::xsgetn().

template<typename _CharT, typename _Traits>
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 511 of file fstream.tcc.

References std::__check_facet(), __N, std::__throw_ios_failure(), std::basic_filebuf< _CharT, _Traits >::_M_buf_size, std::basic_filebuf< _CharT, _Traits >::_M_codecvt, std::basic_filebuf< _CharT, _Traits >::_M_destroy_pback(), std::basic_filebuf< _CharT, _Traits >::_M_file, 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 >::_M_writing, std::copy(), std::basic_streambuf< _CharT, _Traits >::eback(), std::basic_streambuf< _CharT, _Traits >::egptr(), std::basic_streambuf< _CharT, _Traits >::gbump(), std::basic_streambuf< _CharT, _Traits >::gptr(), std::ios_base::in, std::basic_streambuf< _CharT, _Traits >::xsgetn(), and std::__basic_file< char >::xsgetn().

template<typename _CharT, typename _Traits>
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 594 of file fstream.tcc.

References std::__check_facet(), std::basic_filebuf< _CharT, _Traits >::_M_buf_size, std::basic_filebuf< _CharT, _Traits >::_M_codecvt, std::basic_filebuf< _CharT, _Traits >::_M_file, std::basic_filebuf< _CharT, _Traits >::_M_mode, std::basic_filebuf< _CharT, _Traits >::_M_reading, std::basic_filebuf< _CharT, _Traits >::_M_set_buffer(), std::basic_filebuf< _CharT, _Traits >::_M_writing, std::basic_streambuf< _CharT, _Traits >::epptr(), std::min(), std::ios_base::out, std::basic_streambuf< _CharT, _Traits >::pbase(), std::basic_streambuf< _CharT, _Traits >::pptr(), std::basic_streambuf< _CharT, _Traits >::xsputn(), and std::__basic_file< char >::xsputn_2().

Friends And Related Function Documentation

template<typename _CharT, typename _Traits>
friend class ios_base [friend]

Definition at line 84 of file fstream.

Member Data Documentation

template<typename _CharT, typename _Traits>
char_type* std::basic_filebuf< _CharT, _Traits >::_M_buf [protected]

Definition at line 118 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::_M_allocate_internal_buffer(), std::basic_filebuf< _CharT, _Traits >::_M_destroy_internal_buffer(), std::basic_filebuf< _CharT, _Traits >::_M_destroy_pback(), std::basic_filebuf< _CharT, _Traits >::_M_set_buffer(), and std::basic_filebuf< _CharT, _Traits >::setbuf().

template<typename _CharT, typename _Traits>
bool std::basic_filebuf< _CharT, _Traits >::_M_buf_allocated [protected]

Definition at line 130 of file fstream.

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

template<typename _CharT, typename _Traits>
size_t std::basic_filebuf< _CharT, _Traits >::_M_buf_size [protected]

Definition at line 127 of file fstream.

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

template<typename _CharT, typename _Traits>
const __codecvt_type* std::basic_filebuf< _CharT, _Traits >::_M_codecvt [protected]

Definition at line 159 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::_M_convert_to_external(), std::basic_filebuf< _CharT, _Traits >::_M_terminate_output(), std::basic_filebuf< _CharT, _Traits >::basic_filebuf(), std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::seekoff(), std::basic_filebuf< _CharT, _Traits >::showmanyc(), 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]

Definition at line 168 of file fstream.

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

template<typename _CharT, typename _Traits>
streamsize std::basic_filebuf< _CharT, _Traits >::_M_ext_buf_size [protected]

Definition at line 175 of file fstream.

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

template<typename _CharT, typename _Traits>
char* std::basic_filebuf< _CharT, _Traits >::_M_ext_end [protected]

Definition at line 185 of file fstream.

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

template<typename _CharT, typename _Traits>
const char* std::basic_filebuf< _CharT, _Traits >::_M_ext_next [protected]

Definition at line 184 of file fstream.

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

template<typename _CharT, typename _Traits>
__file_type std::basic_filebuf< _CharT, _Traits >::_M_file [protected]

Definition at line 92 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::_M_convert_to_external(), std::basic_filebuf< _CharT, _Traits >::_M_seek(), std::basic_filebuf< _CharT, _Traits >::_M_terminate_output(), std::basic_filebuf< _CharT, _Traits >::close(), __gnu_cxx::stdio_filebuf< _CharT, _Traits >::fd(), __gnu_cxx::stdio_filebuf< _CharT, _Traits >::file(), std::basic_filebuf< _CharT, _Traits >::is_open(), std::basic_filebuf< _CharT, _Traits >::open(), std::basic_filebuf< _CharT, _Traits >::showmanyc(), __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>
__c_lock std::basic_filebuf< _CharT, _Traits >::_M_lock [protected]

Definition at line 89 of file fstream.

template<typename _CharT, typename _Traits>
ios_base::openmode std::basic_filebuf< _CharT, _Traits >::_M_mode [protected]

Definition at line 99 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::_M_set_buffer(), std::basic_filebuf< _CharT, _Traits >::close(), std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::open(), std::basic_filebuf< _CharT, _Traits >::overflow(), std::basic_filebuf< _CharT, _Traits >::pbackfail(), std::basic_filebuf< _CharT, _Traits >::showmanyc(), 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_type std::basic_filebuf< _CharT, _Traits >::_M_pback [protected]

Definition at line 152 of file fstream.

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

template<typename _CharT, typename _Traits>
char_type* std::basic_filebuf< _CharT, _Traits >::_M_pback_cur_save [protected]

Definition at line 153 of file fstream.

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

template<typename _CharT, typename _Traits>
char_type* std::basic_filebuf< _CharT, _Traits >::_M_pback_end_save [protected]

Definition at line 154 of file fstream.

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

template<typename _CharT, typename _Traits>
bool std::basic_filebuf< _CharT, _Traits >::_M_pback_init [protected]

Definition at line 155 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::_M_create_pback(), std::basic_filebuf< _CharT, _Traits >::_M_destroy_pback(), 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]

Definition at line 141 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::_M_seek(), std::basic_filebuf< _CharT, _Traits >::close(), std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::open(), std::basic_filebuf< _CharT, _Traits >::overflow(), std::basic_filebuf< _CharT, _Traits >::pbackfail(), std::basic_filebuf< _CharT, _Traits >::seekoff(), __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>
__state_type std::basic_filebuf< _CharT, _Traits >::_M_state_beg [protected]

Definition at line 102 of file fstream.

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

template<typename _CharT, typename _Traits>
__state_type std::basic_filebuf< _CharT, _Traits >::_M_state_cur [protected]

Definition at line 107 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::_M_convert_to_external(), std::basic_filebuf< _CharT, _Traits >::_M_seek(), std::basic_filebuf< _CharT, _Traits >::_M_terminate_output(), std::basic_filebuf< _CharT, _Traits >::close(), std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::open(), and std::basic_filebuf< _CharT, _Traits >::underflow().

template<typename _CharT, typename _Traits>
__state_type std::basic_filebuf< _CharT, _Traits >::_M_state_last [protected]

Definition at line 111 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(), and std::basic_filebuf< _CharT, _Traits >::underflow().

template<typename _CharT, typename _Traits>
bool std::basic_filebuf< _CharT, _Traits >::_M_writing [protected]

Definition at line 142 of file fstream.

Referenced by std::basic_filebuf< _CharT, _Traits >::_M_seek(), std::basic_filebuf< _CharT, _Traits >::_M_terminate_output(), std::basic_filebuf< _CharT, _Traits >::close(), std::basic_filebuf< _CharT, _Traits >::imbue(), std::basic_filebuf< _CharT, _Traits >::open(), std::basic_filebuf< _CharT, _Traits >::overflow(), std::basic_filebuf< _CharT, _Traits >::pbackfail(), __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().

The documentation for this class was generated from the following files:
Generated on Tue Feb 2 16:59:26 2010 for GNU C++ STL by  doxygen 1.4.7