man std::basic_streambuf< _CharT (3):

SYNOPSIS

Inherited by __gnu_cxx::stdio_sync_filebuf< _CharT, _Traits >, std::basic_filebuf< _CharT, encoding_char_traits< _CharT > >, std::basic_filebuf< char_type, traits_type >, std::basic_filebuf< _CharT, _Traits >, and std::basic_stringbuf< _CharT, _Traits, _Alloc >.

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

Public Member Functions

virtual ~basic_streambuf ()

locale getloc () const

streamsize in_avail ()

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 ()

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

basic_streambuf ()

basic_streambuf (const basic_streambuf &)

void __safe_gbump (streamsize __n)

void __safe_pbump (streamsize __n)

void gbump (int __n)

virtual void imbue (const locale &__loc)

basic_streambuf & operator= (const basic_streambuf &)

virtual int_type overflow (int_type __c=traits_type::eof())

virtual int_type pbackfail (int_type __c=traits_type::eof())

void pbump (int __n)

virtual pos_type seekoff (off_type, ios_base::seekdir, ios_base::openmode=ios_base::in|ios_base::out)

virtual pos_type seekpos (pos_type, ios_base::openmode=ios_base::in|ios_base::out)

virtual basic_streambuf< char_type, _Traits > * setbuf (char_type *, streamsize)

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

locale _M_buf_locale

char_type * _M_in_beg

char_type * _M_in_cur

char_type * _M_in_end

char_type * _M_out_beg

char_type * _M_out_cur

char_type * _M_out_end

Friends

template<bool _IsMove, typename _CharT2 > __gnu_cxx::__enable_if< __is_char< _CharT2 >::__value, _CharT2 * >::__type __copy_move_a2 (istreambuf_iterator< _CharT2 >, istreambuf_iterator< _CharT2 >, _CharT2 *)

streamsize __copy_streambufs_eof (basic_streambuf *, basic_streambuf *, bool &)

class basic_ios< char_type, traits_type >

class basic_istream< char_type, traits_type >

class basic_ostream< char_type, traits_type >

template<typename _CharT2 > __gnu_cxx::__enable_if< __is_char< _CharT2 >::__value, istreambuf_iterator< _CharT2 > >::__type find (istreambuf_iterator< _CharT2 >, istreambuf_iterator< _CharT2 >, const _CharT2 &)

template<typename _CharT2 , typename _Traits2 , typename _Alloc > basic_istream< _CharT2, _Traits2 > & getline (basic_istream< _CharT2, _Traits2 > &, basic_string< _CharT2, _Traits2, _Alloc > &, _CharT2)

class istreambuf_iterator< char_type, traits_type >

template<typename _CharT2 , typename _Traits2 > basic_istream< _CharT2, _Traits2 > & operator>> (basic_istream< _CharT2, _Traits2 > &, _CharT2 *)

template<typename _CharT2 , typename _Traits2 , typename _Alloc > basic_istream< _CharT2, _Traits2 > & operator>> (basic_istream< _CharT2, _Traits2 > &, basic_string< _CharT2, _Traits2, _Alloc > &)

class ostreambuf_iterator< char_type, traits_type >

Detailed Description

template<typename _CharT, typename _Traits>

class std::basic_streambuf< _CharT, _Traits >" The actual work of input and output (interface).

Template Parameters:

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

This is a base class. Derived stream buffers each control a pair of character sequences: one for input, and one for output.

Section [27.5.1] of the standard describes the requirements and behavior of stream buffer classes. That section (three paragraphs) is reproduced here, for simplicity and accuracy.

1.: Stream buffers can impose various constraints on the sequences they control. Some constraints are:
•: The controlled input sequence can be not readable.
•: The controlled output sequence can be not writable.
•: The controlled sequences can be associated with the contents of other representations for character sequences, such as external files.
•: The controlled sequences can support operations directly to or from associated sequences.
•: The controlled sequences can impose limitations on how the program can read characters from a sequence, write characters to a sequence, put characters back into an input sequence, or alter the stream position.

2.: Each sequence is characterized by three pointers which, if non-null, all point into the same charT array object. The array object represents, at any moment, a (sub)sequence of characters from the sequence. Operations performed on a sequence alter the values stored in these pointers, perform reads and writes directly to or from associated sequences, and alter the stream position and conversion state as needed to maintain this subsequence relationship. The three pointers are:
•: the beginning pointer, or lowest element address in the array (called xbeg here);
•: the next pointer, or next element address that is a current candidate for reading or writing (called xnext here);
•: the end pointer, or first element address beyond the end of the array (called xend here).

3.: The following semantic constraints shall always apply for any set of three pointers for a sequence, using the pointer names given immediately above:
•: If xnext is not a null pointer, then xbeg and xend shall also be non-null pointers into the same charT array, as described above; otherwise, xbeg and xend shall also be null.
•: If xnext is not a null pointer and xnext < xend for an output sequence, then a write position is available. In this case, *xnext shall be assignable as the next element to write (to put, or to store a character value, into the sequence).
•: If xnext is not a null pointer and xbeg < xnext for an input sequence, then a putback position is available. In this case, xnext[-1] shall have a defined value and is the next (preceding) element to store a character that is put back into the input sequence.
•: If xnext is not a null pointer and xnext< xend for an input sequence, then a read position is available. In this case, *xnext shall have a defined value and is the next element to read (to get, or to obtain a character value, from the sequence).

Definition at line 80 of file iosfwd.

Member Typedef Documentation