basic_stringbuf::underflow
Protected, virtual function to extract the current element from the input stream.
virtual int_type underflow( );
Return Value
If the function cannot succeed, it returns traits_type::eof. Otherwise, it returns the current element in the input stream, which are converted.
Remarks
The protected virtual member function tries to extract the current element byte from the input buffer, advance the current stream position, and return the element as traits_type::to_int_type(byte). It can do so in one way: If a read position is available, it takes byte as the element stored in the read position and advances the next pointer for the input buffer.
Requirements
Header: <sstream>
Namespace: std