For example, using the code: string line = "\taaa\t\tbbb\t"; typedef tokenizer tok; char_separator<char> sep("\t"); tok tokens(line, sep); for(tok::iterator i = tokens.begin();i!=tokens.end();++i) { cout << "\t\"" << *i << "\"" << endl; } I get this output: "aaa" "bbb" I want to get this output: "" "aaa" "" "bbb" ""