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
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
Referenced by std::wbuffer_convert<_Codecvt,_Elem,_Tr>::underflow().
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
template<typename_CharT,typename_Traits>voidstd::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.
template<typename_CharT,typename_Traits>localestd::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.
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
Referenced by std::wbuffer_convert<_Codecvt,_Elem,_Tr>::underflow().
template<typename_CharT,typename_Traits>virtualvoidstd::basic_streambuf<_CharT,_Traits>::imbue(constlocale&__loc)[inline],[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, Betweeninvocationsofthisfunctionaclassderivedfromstreambufcansafelycacheresultsofcallstolocalefunctionsandtomembersoffacetssoobtained.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>.
template<typename_CharT,typename_Traits>streamsizestd::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().
template<class_CharT,class_Traits,class_Alloc>basic_stringbuf<_CharT,_Traits,_Alloc>::int_typestd::basic_stringbuf<_CharT,_Traits,_Alloc>::overflow(int_type__c=traits_type::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 someeffect 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::ios_base::in, std::max(), std::min(), and std::ios_base::out.
template<class_CharT,class_Traits,class_Alloc>basic_stringbuf<_CharT,_Traits,_Alloc>::int_typestd::basic_stringbuf<_CharT,_Traits,_Alloc>::pbackfail(int_type__c=traits_type::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, someothervalue 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>.
References std::ios_base::out.
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
template<typename_CharT,typename_Traits>voidstd::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.
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
template<typename_CharT,typename_Traits>localestd::basic_streambuf<_CharT,_Traits>::pubimbue(constlocale&__loc)[inline],[inherited]
Entry point for imbue().
Parameters__loc The new locale.
Returns
The previous locale.
Calls the derived imbue(__loc).
template<typename_CharT,typename_Traits>pos_typestd::basic_streambuf<_CharT,_Traits>::pubseekoff(off_type__off,ios_base::seekdir__way,ios_base::openmode__mode=ios_base::in|ios_base::out)[inline],[inherited]
Alters the stream position.
Parameters__off Offset.
__way Value for ios_base::seekdir.
__mode Value for ios_base::openmode.
Calls virtual seekoff function.
template<typename_CharT,typename_Traits>pos_typestd::basic_streambuf<_CharT,_Traits>::pubseekpos(pos_type__sp,ios_base::openmode__mode=ios_base::in|ios_base::out)[inline],[inherited]
Alters the stream position.
Parameters__sp Position
__mode Value for ios_base::openmode.
Calls virtual seekpos function.
template<typename_CharT,typename_Traits>basic_streambuf*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.
template<typename_CharT,typename_Traits>intstd::basic_streambuf<_CharT,_Traits>::pubsync()[inline],[inherited]
Calls virtual sync function.
template<typename_CharT,typename_Traits>int_typestd::basic_streambuf<_CharT,_Traits>::sbumpc()[inline],[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().
template<class_CharT,class_Traits,class_Alloc>basic_stringbuf<_CharT,_Traits,_Alloc>::pos_typestd::basic_stringbuf<_CharT,_Traits,_Alloc>::seekoff(off_type,ios_base::seekdir,ios_base::openmode=ios_base::in|ios_base::out)[protected],[virtual]
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>.
References std::ios_base::cur, std::ios_base::end, std::ios_base::in, and std::ios_base::out.
template<class_CharT,class_Traits,class_Alloc>basic_stringbuf<_CharT,_Traits,_Alloc>::pos_typestd::basic_stringbuf<_CharT,_Traits,_Alloc>::seekpos(pos_type,ios_base::openmode=ios_base::in|ios_base::out)[protected],[virtual]
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>.
References std::ios_base::in, and std::ios_base::out.
template<typename_CharT,typename_Traits,typename_Alloc>virtual__streambuf_type*std::basic_stringbuf<_CharT,_Traits,_Alloc>::setbuf(char_type*__s,streamsize__n)[inline],[protected],[virtual]
Manipulates the buffer.
Parameters__s Pointer to a buffer area.
__n Size of __s.
Returns
this
If no buffer has already been created, and both __s and __n are non-zero, then __s is used as a buffer;
see https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering for more.
Reimplemented from std::basic_streambuf<_CharT,_Traits>.
template<typename_CharT,typename_Traits>voidstd::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()
Referenced by std::wbuffer_convert<_Codecvt,_Elem,_Tr>::wbuffer_convert().
template<typename_CharT,typename_Traits>voidstd::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()
Referenced by std::wbuffer_convert<_Codecvt,_Elem,_Tr>::wbuffer_convert().
template<typename_CharT,typename_Traits>int_typestd::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.
template<typename_CharT,typename_Traits>streamsizestd::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.
template<typename_CharT,typename_Traits,typename_Alloc>virtualstreamsizestd::basic_stringbuf<_CharT,_Traits,_Alloc>::showmanyc()[inline],[protected],[virtual]
Investigating the data available.
Returns
An estimate of the number of characters available in the input sequence, or -1.
Ifitreturnsapositivevalue,thensuccessivecallstounderflow()willnotreturntraits::eof()untilatleastthatnumberofcharactershavebeensupplied.Ifshowmanyc()returns-1,thencallstounderflow()oruflow()willfail.[27.5.2.4.3]/1Note
Base class version does nothing, returns zero.
The standard adds that theintentionisnotonlythatthecalls[tounderfloworuflow]willnotreturneof()butthattheywillreturnimmediately.
The standard adds that themorphemesofshowmanycarees-how-many-see,notshow-manic.
Reimplemented from std::basic_streambuf<_CharT,_Traits>.
template<typename_CharT,typename_Traits>int_typestd::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().
template<typename_CharT,typename_Traits>int_typestd::basic_streambuf<_CharT,_Traits>::sputbackc(char_type__c)[inline],[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 thepreviouscharacter. If successful,
the next character fetched from the input stream will be __c.
template<typename_CharT,typename_Traits>int_typestd::basic_streambuf<_CharT,_Traits>::sputc(char_type__c)[inline],[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).
Referenced by std::wbuffer_convert<_Codecvt,_Elem,_Tr>::overflow().
template<typename_CharT,typename_Traits>streamsizestd::basic_streambuf<_CharT,_Traits>::sputn(constchar_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.
template<typename_CharT,typename_Traits,typename_Alloc>__string_typestd::basic_stringbuf<_CharT,_Traits,_Alloc>::str()const[inline]
Copying out the string buffer.
Returns
A copy of one of the underlying sequences.
Ifthebufferisonlycreatedininputmode,theunderlyingcharactersequenceisequaltotheinputsequence;otherwise,itisequaltotheoutputsequence. [27.7.1.2]/1
template<typename_CharT,typename_Traits,typename_Alloc>voidstd::basic_stringbuf<_CharT,_Traits,_Alloc>::str(const__string_type&__s)[inline]
Setting a new buffer.
Parameters__s The string to use as a new sequence.
Deallocates any previous stored sequence, then copies s to use as a new one.
template<typename_CharT,typename_Traits>int_typestd::basic_streambuf<_CharT,_Traits>::sungetc()[inline],[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.
template<typename_CharT,typename_Traits>virtualintstd::basic_streambuf<_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 in std::wbuffer_convert<_Codecvt,_Elem,_Tr>, __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>>, and std::basic_filebuf<char_type,traits_type>.
template<typename_CharT,typename_Traits>virtualint_typestd::basic_streambuf<_CharT,_Traits>::uflow()[inline],[protected],[virtual],[inherited]
Fetches more data from the controlled sequence.
Returns
The first character from the pendingsequence.
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>.
template<class_CharT,class_Traits,class_Alloc>basic_stringbuf<_CharT,_Traits,_Alloc>::int_typestd::basic_stringbuf<_CharT,_Traits,_Alloc>::underflow()[protected],[virtual]
Fetches more data from the controlled sequence.
Returns
The first character from the pendingsequence.
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::ios_base::in.
template<typename_CharT,typename_Traits>streamsizestd::basic_streambuf<_CharT,_Traits>::xsgetn(char_type*__s,streamsize__n)[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 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().
template<typename_CharT,typename_Traits>streamsizestd::basic_streambuf<_CharT,_Traits>::xsputn(constchar_type*__s,streamsize__n)[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 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().