Is there a problem with returning a tokenizer from a function? Here's what I've got: typedef boost::tokenizer< boost::char_separator<char> > tokenizer; tokenizer getTokens( istream& is ) { boost::char_separator<char> sep(",","", boost::keep_empty_tokens); std::string str; getline(is,str,'\n'); tokenizer toks( str, sep ); return toks; } .. tokenizer tokens = getTokens(input); tokenizer::iterator it = tokens.begin(); (*it) now contains garbage, interesting enough, iterating through the rest of the container works. when I move the processing of getTokens into the main code body the first token (*it) is then correct. Am I missing something fundamental here?