std::wbuffer_convert - Man Page

typedef _Codecvt::state_type state_type

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
This is a non-standard type.

wbuffer_convert ()
Default constructor.
wbuffer_convert (const wbuffer_convert &)=delete
wbuffer_convert (streambuf *__bytebuf, _Codecvt *__pcvt=new _Codecvt, state_type __state=state_type())
locale getloc () const
Locale access.
streamsize in_avail ()
Looking ahead into the stream.
wbuffer_convert & operator= (const wbuffer_convert &)=delete
locale pubimbue (const locale &__loc)
Entry point for imbue().
streambuf * rdbuf () const noexcept
streambuf * rdbuf (streambuf *__bytebuf) noexcept
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 snextc ()
Getting the next character.
int_type sputbackc (char_type __c)
Pushing characters back into 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.
state_type state () const noexcept
The conversion state following the last conversion.
int_type sungetc ()
Moving backwards in the input stream.

basic_streambuf * 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)
Alters the stream position.
pos_type pubseekpos (pos_type __sp, ios_base::openmode __mode=ios_base::in|ios_base::out)
Alters the stream position.
int pubsync ()
Calls virtual sync function.

void __safe_gbump (streamsize __n)
void __safe_pbump (streamsize __n)
void gbump (int __n)
Moving the read position.
virtual void imbue (const locale &__loc)
Changes translations.
_Wide_streambuf::int_type overflow (typename _Wide_streambuf::int_type __out)
Consumes data from the buffer; writes to the controlled sequence.
virtual int_type pbackfail (int_type __c=traits_type::eof())
Tries to back up the input sequence.
void pbump (int __n)
Moving the write position.
virtual pos_type seekoff (off_type, ios_base::seekdir, ios_base::openmode=ios_base::in|ios_base::out)
Alters the stream positions.
virtual pos_type seekpos (pos_type, ios_base::openmode=ios_base::in|ios_base::out)
Alters the stream positions.
virtual basic_streambuf< char_type, _Traits > * setbuf (char_type *, streamsize)
Manipulates the buffer.
void setg (char_type *__gbeg, char_type *__gnext, char_type *__gend)
Setting the three read area pointers.
void setp (char_type *__pbeg, char_type *__pend)
Setting the three write area pointers.
virtual streamsize showmanyc ()
Investigating the data available.
void swap (basic_streambuf &__sb)
int sync ()
Synchronizes the buffer arrays with the controlled sequences.
virtual int_type uflow ()
Fetches more data from the controlled sequence.
_Wide_streambuf::int_type underflow ()
Fetches more data from the controlled sequence.
virtual streamsize xsgetn (char_type *__s, streamsize __n)
Multiple character extraction.
virtual streamsize xsputn (const char_type *__s, streamsize __n)
Multiple character insertion.
streamsize xsputn (const typename _Wide_streambuf::char_type *__s, streamsize __n)

char_type * eback () const
Access to the get area.
char_type * gptr () const
Access to the get area.
char_type * egptr () const
Access to the get area.

char_type * pbase () const
Access to the put area.
char_type * pptr () const
Access to the put area.
char_type * epptr () const
Access to the put area.

locale _M_buf_locale
Current locale setting.
char_type * _M_in_beg
Start of get area.
char_type * _M_in_cur
Current read area.
char_type * _M_in_end
End of get area.
char_type * _M_out_beg
Start of put area.
char_type * _M_out_cur
Current put area.
char_type * _M_out_end
End of put area.

class std::wbuffer_convert< _Codecvt, _Elem, _Tr >"Buffer conversions.

This is a non-standard type.

These are standard types. They permit a standardized way of referring to names of (or names dependent on) the template parameters, which are specific to the implementation.

These are standard types. They permit a standardized way of referring to names of (or names dependent on) the template parameters, which are specific to the implementation.

These are standard types. They permit a standardized way of referring to names of (or names dependent on) the template parameters, which are specific to the implementation.

These are standard types. They permit a standardized way of referring to names of (or names dependent on) the template parameters, which are specific to the implementation.

These are standard types. They permit a standardized way of referring to names of (or names dependent on) the template parameters, which are specific to the implementation.

Default constructor.

Constructor.

Parameters

Takes ownership of __pcvt and will delete it in the destructor.

References std::basic_streambuf< _CharT, _Traits >::setg(), and std::basic_streambuf< _CharT, _Traits >::setp().

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

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

Referenced by std::wbuffer_convert< _Codecvt, _Elem, _Tr >::underflow().

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

Moving the read position.

Parameters

This just advances the read position without returning any data.

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.

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

Referenced by std::wbuffer_convert< _Codecvt, _Elem, _Tr >::underflow().

Changes translations.

Parameters

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 in std::basic_filebuf< _CharT, _Traits >, std::basic_filebuf< _CharT, encoding_char_traits< _CharT > >, std::basic_filebuf< _CharT, std::char_traits< _CharT > >, and std::basic_filebuf< char_type, traits_type >.

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().

Consumes data from the buffer; writes to the controlled sequence.

Parameters

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 >.

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

Tries to back up the input sequence.

Parameters

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

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

Moving the write position.

Parameters

This just advances the write position without returning any data.

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

Entry point for imbue().

Parameters

Returns

The previous locale.

Calls the derived imbue(__loc).

Alters the stream position.

Parameters

Calls virtual seekoff function.

Alters the stream position.

Parameters

Calls virtual seekpos function.

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.

Calls virtual sync function.

Referenced by std::basic_istream< _CharT, _Traits >::sync(), and std::wbuffer_convert< _Codecvt, _Elem, _Tr >::sync().

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().

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

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 in std::basic_filebuf< _CharT, _Traits >, std::basic_filebuf< _CharT, encoding_char_traits< _CharT > >, std::basic_filebuf< _CharT, std::char_traits< _CharT > >, std::basic_filebuf< char_type, traits_type >, and std::basic_stringbuf< _CharT, _Traits, _Alloc >.

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 in std::basic_filebuf< _CharT, _Traits >, std::basic_filebuf< _CharT, encoding_char_traits< _CharT > >, std::basic_filebuf< _CharT, std::char_traits< _CharT > >, std::basic_filebuf< char_type, traits_type >, and std::basic_stringbuf< _CharT, _Traits, _Alloc >.

Manipulates the buffer. Each derived class provides its own appropriate behavior. See the next-to-last paragraph of https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering for more on this function.

Note

Base class version does nothing, returns this.

Reimplemented in std::basic_filebuf< _CharT, _Traits >, std::basic_filebuf< _CharT, encoding_char_traits< _CharT > >, std::basic_filebuf< _CharT, std::char_traits< _CharT > >, std::basic_filebuf< char_type, traits_type >, and std::basic_stringbuf< _CharT, _Traits, _Alloc >.

Setting the three read area pointers.

Parameters

Postcondition

Referenced by std::wbuffer_convert< _Codecvt, _Elem, _Tr >::wbuffer_convert().

Setting the three write area pointers.

Parameters

Postcondition

Referenced by std::wbuffer_convert< _Codecvt, _Elem, _Tr >::wbuffer_convert().

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.

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

Entry point for xsgetn.

Parameters

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

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 in std::basic_filebuf< _CharT, _Traits >, std::basic_filebuf< _CharT, encoding_char_traits< _CharT > >, std::basic_filebuf< _CharT, std::char_traits< _CharT > >, std::basic_filebuf< char_type, traits_type >, and std::basic_stringbuf< _CharT, _Traits, _Alloc >.

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().

Referenced by std::basic_istream< _CharT, char_traits< _CharT > >::get(), std::basic_istream< _CharT, char_traits< _CharT > >::ignore(), std::basic_istream< _CharT, char_traits< _CharT > >::operator>>(), and std::basic_istream< _CharT, char_traits< _CharT > >::putback().

Pushing characters back into the input stream.

Parameters

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.

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

Entry point for all single-character output functions.

Parameters

Returns

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).

Referenced by std::ostreambuf_iterator< _CharT, _Traits >::operator=(), and std::wbuffer_convert< _Codecvt, _Elem, _Tr >::overflow().

Entry point for all single-character output functions.

Parameters

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.

The conversion state following the last conversion.

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.

Synchronizes the buffer arrays with the controlled sequences.

Returns

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 >.

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

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 >.

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 >.

References std::basic_streambuf< _CharT, _Traits >::egptr(), and std::basic_streambuf< _CharT, _Traits >::gptr().

Multiple character extraction.

Parameters

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 in std::basic_filebuf< _CharT, _Traits >, std::basic_filebuf< _CharT, encoding_char_traits< _CharT > >, std::basic_filebuf< _CharT, std::char_traits< _CharT > >, and std::basic_filebuf< char_type, traits_type >.

References std::min().

Multiple character insertion.

Parameters

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 in std::basic_filebuf< _CharT, _Traits >, std::basic_filebuf< _CharT, encoding_char_traits< _CharT > >, std::basic_filebuf< _CharT, std::char_traits< _CharT > >, and std::basic_filebuf< char_type, traits_type >.

References std::min().

Current locale setting.

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

Start of get area.

Current read area.

End of get area.

Start of put area.

Current put area.

End of put area.