Defined in header

void open( const char *filename, ios_base::openmode mode = ios_base::in

char* str() const;

protected: virtual int_type underflow()

protected: void swap(basic_istream& rhs);

explicit basic_stringstream( ios_base::openmode mode = ios_base::in|ios_base::out

basic_filebuf(); (1)

fmtflags setf( fmtflags flags ); (1)

virtual int_type underflow();

explicit basic_ostringstream( ios_base::openmode mode = ios_base::out );