__gnu_cxx::stdio_filebuf< CharT, Traits > Class Template Reference

Provides a layer of compatibility for C/POSIX. More...

#include <ext/stdio_filebuf.h>

Inheritance diagram for __gnu_cxx::stdio_filebuf< CharT, Traits >:

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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

Public Member Functions

 stdio_filebuf (int __fd, std::ios_base::openmode __mode, bool __del, size_t size)
 stdio_filebuf (std::c_file *__f, std::ios_base::openmode __mode, size_t size=static_cast< size_t >(BUFSIZ))
virtual ~stdio_filebuf ()
int fd ()
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.
locale pubimbue (const locale &__loc)
 Entry point for imbue().
locale getloc () const
 Locale access.
streamsize in_avail ()
 Looking ahead into the stream.
int_type snextc ()
 Getting the next character.
int_type sbumpc ()
 Getting the next character.
int_type sgetc ()
 Getting the next character.
streamsize sgetn (char_type *s, streamsize n)
 Entry point for xsgetn.
int_type sputbackc (char_type c)
 Pushing characters back into the input stream.
int_type sungetc ()
 Moving backwards in the input stream.
int_type sputc (char_type c)
 Entry point for all single-character output functions.
streamsize sputn (const char_type *s, streamsize n)
 Entry point for all single-character output functions.
streambuf_type * pubsetbuf (char_type *s, streamsize n)
 Entry points for derived buffer functions.
pos_type pubseekoff (off_type __off, ios_base::seekdir __way, ios_base::openmode __mode=ios_base::in|ios_base::out)
 Entry points for derived buffer functions.
pos_type pubseekpos (pos_type sp, ios_base::openmode __mode=ios_base::in|ios_base::out)
 Entry points for derived buffer functions.
int pubsync ()
 Entry points for derived buffer functions.

Protected Member Functions

virtual streamsize showmanyc ()
 Investigating the data available.
virtual int_type underflow ()
 Fetches more data from the controlled sequence.
virtual int_type uflow ()
 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.
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)
 Alters the stream positions.
virtual pos_type seekpos (pos_type position, ios_base::openmode __mode=ios_base::in|ios_base::out)
 Alters the stream positions.
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.
void gbump (int n)
 Moving the read position.
void setg (char_type *__gbeg, char_type *__gnext, char_type *__gend)
 Setting the three read area pointers.
void pbump (int n)
 Moving the write position.
void setp (char_type *__pbeg, char_type *__pend)
 Setting the three write area pointers.
char_typeeback () const
 Access to the get area.
char_typegptr () const
 Access to the get area.
char_typeegptr () const
 Access to the get area.
char_typepbase () const
 Access to the put area.
char_typepptr () const
 Access to the put area.
char_typeepptr () const
 Access to the put area.

Detailed Description

template<typename CharT, typename Traits = std::char_traits<CharT>>
class __gnu_cxx::stdio_filebuf< CharT, Traits >

Provides a layer of compatibility for C/POSIX.

This GNU extension provides extensions for working with standard C FILE*'s and POSIX file descriptors. It must be instantiated by the user with the type of character used in the file stream, e.g., stdio_filebuf<char>.

Definition at line 52 of file stdio_filebuf.h.


Member Typedef Documentation

template<typename CharT, typename Traits = std::char_traits<CharT>>
typedef CharT __gnu_cxx::stdio_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_filebuf< CharT, Traits >.

Definition at line 56 of file stdio_filebuf.h.

template<typename CharT, typename Traits = std::char_traits<CharT>>
typedef traits_type::int_type __gnu_cxx::stdio_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_filebuf< CharT, Traits >.

Definition at line 58 of file stdio_filebuf.h.

template<typename CharT, typename Traits = std::char_traits<CharT>>
typedef traits_type::off_type __gnu_cxx::stdio_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_filebuf< CharT, Traits >.

Definition at line 60 of file stdio_filebuf.h.

template<typename CharT, typename Traits = std::char_traits<CharT>>
typedef traits_type::pos_type __gnu_cxx::stdio_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_filebuf< CharT, Traits >.

Definition at line 59 of file stdio_filebuf.h.

template<typename CharT, typename Traits = std::char_traits<CharT>>
typedef Traits __gnu_cxx::stdio_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_filebuf< CharT, Traits >.

Definition at line 57 of file stdio_filebuf.h.


Constructor & Destructor Documentation

template<typename CharT, typename Traits>
__gnu_cxx::stdio_filebuf< CharT, Traits >::stdio_filebuf int  __fd,
std::ios_base::openmode  __mode,
bool  __del,
size_t  size
 

Parameters:
fd An open file descriptor.
mode Same meaning as in a standard filebuf.
del Whether to close the file on destruction.
size Optimal or preferred size of internal buffer, in bytes.
This constructor associates a file stream buffer with an open POSIX file descriptor. Iff del is true, then the associated file will be closed when the stdio_filebuf is closed/destroyed.

Definition at line 120 of file stdio_filebuf.h.

template<typename CharT, typename Traits>
__gnu_cxx::stdio_filebuf< CharT, Traits >::stdio_filebuf std::c_file *  __f,
std::ios_base::openmode  __mode,
size_t  size = static_cast< size_t >(BUFSIZ)
 

Parameters:
f An open FILE*.
mode Same meaning as in a standard filebuf.
size Optimal or preferred size of internal buffer, in bytes. Defaults to system's BUFSIZ.
This constructor associates a file stream buffer with an open C FILE*. The FILE* will not be automatically closed when the stdio_filebuf is closed/destroyed.

Definition at line 145 of file stdio_filebuf.h.

template<typename CharT, typename Traits>
__gnu_cxx::stdio_filebuf< CharT, Traits >::~stdio_filebuf  )  [virtual]
 

Possibly closes the external data stream, in the case of the file descriptor constructor and del == true.

Definition at line 115 of file stdio_filebuf.h.


Member Function Documentation

template<typename CharT, typename Traits>
basic_filebuf< CharT, Traits >::__filebuf_type * std::basic_filebuf< CharT, Traits >::close  )  throw () [inherited]
 

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 114 of file fstream.tcc.

Referenced by std::basic_filebuf< CharT, Traits >::open(), and std::basic_filebuf< CharT, enc_char_traits< CharT > >::~basic_filebuf().

template<typename CharT, typename Traits>
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
  • gptr() returns the next pointer for the input sequence
  • egptr() returns the end pointer for the input sequence

Definition at line 599 of file streambuf.

Referenced by std::basic_stringbuf< CharT, Traits, Alloc >::seekpos().

template<typename CharT, typename Traits>
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
  • gptr() returns the next pointer for the input sequence
  • egptr() returns the end pointer for the input sequence

Definition at line 605 of file streambuf.

Referenced by std::basic_streambuf< CharT, enc_char_traits< CharT > >::in_avail(), std::basic_stringbuf< CharT, Traits, Alloc >::seekoff(), and std::basic_stringbuf< CharT, Traits, Alloc >::seekpos().

template<typename CharT, typename Traits>
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
  • pptr() returns the next pointer for the output sequence
  • epptr() returns the end pointer for the output sequence

Definition at line 654 of file streambuf.

Referenced by std::basic_stringbuf< CharT, Traits, Alloc >::seekoff().

template<typename CharT, typename Traits = std::char_traits<CharT>>
int __gnu_cxx::stdio_filebuf< CharT, Traits >::fd  )  [inline]
 

Returns:
The underlying file descriptor.
Once associated with an external data stream, this function can be used to access the underlying POSIX file descriptor. Note that there is no way for the library to track what you do with the descriptor, so be careful.

Definition at line 110 of file stdio_filebuf.h.

template<typename CharT, typename Traits>
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 615 of file streambuf.

template<typename CharT, typename Traits>
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 395 of file streambuf.

Referenced by std::basic_ios< CharT, Traits >::copyfmt(), and std::basic_filebuf< CharT, Traits >::showmanyc().

template<typename CharT, typename Traits>
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
  • gptr() returns the next pointer for the input sequence
  • egptr() returns the end pointer for the input sequence

Definition at line 602 of file streambuf.

Referenced by std::basic_streambuf< CharT, enc_char_traits< CharT > >::in_avail(), std::basic_streambuf< CharT, Traits >::sbumpc(), std::basic_stringbuf< CharT, Traits, Alloc >::seekoff(), and std::basic_stringbuf< CharT, Traits, Alloc >::underflow().

template<typename CharT, typename Traits>
void std::basic_filebuf< CharT, Traits >::imbue const locale &  __loc  )  [protected, virtual, inherited]
 

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 509 of file fstream.tcc.

template<typename CharT, typename Traits>
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().

Definition at line 435 of file streambuf.

template<typename CharT, typename Traits>
bool std::basic_filebuf< CharT, Traits >::is_open  )  const throw () [inline, inherited]
 

Returns true if the external file is open.

Definition at line 161 of file fstream.

Referenced by std::basic_fstream< CharT, Traits >::is_open(), std::basic_ofstream< CharT, Traits >::is_open(), std::basic_ifstream< CharT, Traits >::is_open(), and std::basic_filebuf< CharT, enc_char_traits< CharT > >::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
[inherited]
 

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 83 of file fstream.tcc.

References std::basic_filebuf< CharT, Traits >::close().

template<typename CharT, typename Traits>
basic_filebuf< CharT, Traits >::int_type std::basic_filebuf< CharT, Traits >::overflow int_type  c = Traits::eof()  )  [protected, virtual, inherited]
 

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 253 of file fstream.tcc.

template<typename CharT, typename Traits>
basic_filebuf< CharT, Traits >::int_type std::basic_filebuf< CharT, Traits >::pbackfail int_type  __i = Traits::eof()  )  [protected, virtual, inherited]
 

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 180 of file fstream.tcc.

References std::basic_filebuf< CharT, Traits >::underflow().

template<typename CharT, typename Traits>
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
  • pptr() returns the next pointer for the output sequence
  • epptr() returns the end pointer for the output sequence

Definition at line 648 of file streambuf.

Referenced by std::basic_stringbuf< CharT, Traits, Alloc >::seekpos().

template<typename CharT, typename Traits>
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 664 of file streambuf.

template<typename CharT, typename Traits>
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
  • pptr() returns the next pointer for the output sequence
  • epptr() returns the end pointer for the output sequence

Definition at line 651 of file streambuf.

Referenced by std::basic_stringbuf< CharT, Traits, Alloc >::seekoff().

template<typename CharT, typename Traits>
locale std::basic_streambuf< CharT, Traits >::pubimbue const locale &  __loc  )  [inline, inherited]
 

Entry point for imbue().

Parameters:
loc The new locale.
Returns:
The previous locale.
Calls the derived imbue(loc).

Definition at line 378 of file streambuf.

Referenced by std::basic_ios< CharT, Traits >::imbue().

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
[inline, inherited]
 

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 412 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
[inline, inherited]
 

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 417 of file streambuf.

template<typename CharT, typename Traits>
streambuf_type* std::basic_streambuf< CharT, Traits >::pubsetbuf char_type s,
streamsize  n
[inline, inherited]
 

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 408 of file streambuf.

template<typename CharT, typename Traits>
int std::basic_streambuf< CharT, Traits >::pubsync  )  [inline, inherited]
 

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 422 of file streambuf.

template<typename CharT, typename Traits>
basic_streambuf< CharT, Traits >::int_type std::basic_streambuf< CharT, Traits >::sbumpc  )  [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 49 of file streambuf.tcc.

References std::basic_streambuf< CharT, Traits >::gptr(), and std::basic_streambuf< CharT, Traits >::uflow().

Referenced by std::operator>>().

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, inherited]
 

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 430 of file fstream.tcc.

References std::max(), and std::basic_filebuf< CharT, Traits >::sync().

Referenced by std::basic_filebuf< CharT, Traits >::seekpos(), and std::basic_filebuf< CharT, enc_char_traits< CharT > >::sync().

template<typename CharT, typename Traits>
basic_filebuf< CharT, Traits >::pos_type std::basic_filebuf< CharT, Traits >::seekpos pos_type  position,
ios_base::openmode  __mode = ios_base::in | ios_base::out
[protected, virtual, inherited]
 

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 492 of file fstream.tcc.

References 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
[protected, virtual, inherited]
 

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 405 of file fstream.tcc.

template<typename CharT, typename Traits>
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.
Postcondition:
gbeg == eback(), gnext == gptr(), and gend == egptr()

Definition at line 626 of file streambuf.

template<typename CharT, typename Traits>
void std::basic_streambuf< CharT, Traits >::setp char_type __pbeg,
char_type __pend
[inline, protected, inherited]
 

Setting the three write area pointers.

Parameters:
pbeg A pointer.
pend A pointer.
Postcondition:
pbeg == pbase(), pbeg == pptr(), and pend == epptr()

Definition at line 674 of file streambuf.

template<typename CharT, typename Traits>
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 489 of file streambuf.

Referenced by std::basic_streambuf< CharT, enc_char_traits< CharT > >::snextc().

template<typename CharT, typename Traits>
streamsize std::basic_streambuf< CharT, Traits >::sgetn char_type s,
streamsize  n
[inline, inherited]
 

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 508 of file streambuf.

template<typename CharT, typename Traits>
streamsize std::basic_filebuf< CharT, Traits >::showmanyc  )  [protected, virtual, inherited]
 

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 159 of file fstream.tcc.

References std::basic_streambuf< CharT, Traits >::getloc().

template<typename CharT, typename Traits>
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 462 of file streambuf.

template<typename CharT, typename Traits>
basic_streambuf< CharT, Traits >::int_type std::basic_streambuf< CharT, Traits >::sputbackc char_type  c  )  [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 66 of file streambuf.tcc.

References std::basic_streambuf< CharT, Traits >::pbackfail().

Referenced by std::operator>>().

template<typename CharT, typename Traits>
basic_streambuf< CharT, Traits >::int_type std::basic_streambuf< CharT, Traits >::sputc char_type  c  )  [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 104 of file streambuf.tcc.

References std::basic_streambuf< CharT, Traits >::overflow().

Referenced by std::basic_stringbuf< CharT, Traits, Alloc >::overflow().

template<typename CharT, typename Traits>
streamsize std::basic_streambuf< CharT, Traits >::sputn const char_type s,
streamsize  n
[inline, inherited]
 

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 564 of file streambuf.

template<typename CharT, typename Traits>
basic_streambuf< CharT, Traits >::int_type std::basic_streambuf< CharT, Traits >::sungetc  )  [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 83 of file streambuf.tcc.

References std::basic_streambuf< CharT, Traits >::pbackfail().

template<typename CharT, typename Traits>
virtual int std::basic_filebuf< CharT, Traits >::sync  )  [inline, protected, virtual, inherited]
 

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 311 of file fstream.

Referenced by std::basic_filebuf< CharT, Traits >::seekoff(), and std::basic_filebuf< CharT, enc_char_traits< CharT > >::sync().

template<typename CharT, typename Traits>
basic_filebuf< CharT, Traits >::int_type std::basic_filebuf< CharT, Traits >::uflow  )  [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 from std::basic_streambuf< CharT, Traits >.

Definition at line 458 of file fstream.

template<typename CharT, typename Traits>
basic_filebuf< CharT, Traits >::int_type std::basic_filebuf< CharT, Traits >::underflow  )  [protected, virtual, inherited]
 

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 453 of file fstream.

Referenced by std::basic_filebuf< CharT, Traits >::pbackfail().

template<typename CharT, typename Traits>
virtual streamsize std::basic_filebuf< CharT, Traits >::xsgetn char_type s,
streamsize  n
[inline, protected, virtual, inherited]
 

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 343 of file fstream.

template<typename CharT, typename Traits>
virtual streamsize std::basic_filebuf< CharT, Traits >::xsputn const char_type s,
streamsize  n
[inline, protected, virtual, inherited]
 

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 365 of file fstream.


The documentation for this class was generated from the following file:
Generated on Thu Feb 10 23:23:45 2005 for libstdc++-v3 Source by  doxygen 1.4.0