Small correction to the code: //------- code start -------------------------------- #include <algorithm> #include <map> #include <string> #include <iostream> #include <boost/lambda/lambda.hpp> #include <boost/lambda/bind.hpp> typedef std::map<int, int> MyMap; std::ostream& operator << (std::ostream& outs, const MyMap& a) { std::for_each(a.begin(), a.end(), outs << boost::lambda::bind(&MyMap::value_type::second, boost::lambda::_1) << "\n"); return outs; } int main() { MyMap a; std::cout << a; } //------- code end --------------------------------- Pavel --- This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorized copying, disclosure or distribution of the material in this e-mail is strictly forbidden. Please refer to http://www.db.com/en/content/eu_disclosures.htm for additional EU corporate and regulatory disclosures.