how this function read text into a struct?

Question

I am trying to understand what exactly the following function is doing. It is used to read a text file into a struct , called AEntry , which only contains four ints.

The file contains a list of lines. Each line holds four ints delimited with spaces (or tab ).

when this function is called, a line of istream and a AEntry struct are passed in.

My question is how the delimitors, spacess or tabs, are filtered out? or my understanding is wrong.

istream& operator>>( istream &stream, AEntry& val )
{
    stream >> val.kv;
    stream >> val.col;
    stream >> val.bo;
    stream >> val.Offset;
    return stream;
}

Answer 1

They're filtered out because that's the behavior of the default overloads of istream::operator>> . They stop at whitespace and discard it instead of incorporating it into the extracted output.