int underflow ( );
Get current character.
Returns the character at current get position, or EOF (traits::eof) if the current get pointer is at the end of the input sequence.
This virtual protected function is called by sgetc and other input member functions when the characters remaining to be read in the internal input buffer have exhausted (i.e., gptr>=egptr)
As a virtual function it can be overriden in derived classes in order to provide additional input positions to be read and to set appropriate values for gptr and egptr pointers if, for example, the external source of characters used by the streambuf-derived object hasn't still reached its physical end.
The character available at the get position.
EOF if the get pointer is at the end of the input sequence.
Basic template member declaration ( basic_streambuf<charT,traits> ):
typedef traits::int_type int_type; int_type underflow ( );