Hello List, I am having an issue compiling the my code - I get the following error: xml.hpp:43: error: no matching function for call to ‘regex_search(boost::asio::buffers_iterator<boost::asio::const_buffers_1, char>&, boost::asio::buffers_iterator<boost::asio::const_buffers_1, char>&, boost::match_results<boost::asio::buffers_iterator<boost::asio::const_buffers_1, char>, std::allocator<boost::sub_match<boost::asio::buffers_iterator<boost::asio::const_buffers_1, char> > > >&, boost::_bi::bind_t<boost::regex&, boost::_mfi::mf0<boost::regex&, xmpp::xml::parser>, boost::_bi::list1<boost::_bi::value<const xmpp::xml::parser*> > >, boost::regex_constants::match_flags)’ Here is the related code snippet: template <typename iterator> std::pair<iterator, bool> operator()( iterator begin, iterator end ) const { if(begin == end) { return std::make_pair(end,false); } boost::match_results<iterator> match_results; //Compiler Error Start if(boost::regex_search( begin, end, match_results, boost::bind( &parser::regex, this ), boost::match_default | boost::match_partial)) { //Compiler Error End if(match_results[0].matched) { //test return std::make_pair(match_results[0].second,true); }else{ //test return std::make_pair(match_results[0].first,false); } } return std::make_pair(end,false); }; private: boost::regex regex( ){ return XMLDecl_; }; static boost::regex S_, Eq_, EncName_, VersionInfo_, EncodingDecl_, SDDecl_, XMLDecl_, UTF8_, Char_, NameStartChar_, NameChar_, Name_, Names_, Comment_, PITarget_, PI_, Misc_, prolog_; Could someone please shed some light on this problem for me. I want to be able to change the regular expression based on a state variable so that operator() can advance to the next xml type that it should/could encounter. Thank you. Etienne