Thanks to Steven and my own thinking a solution: #include <iostream> #include <map> #include <boost/lambda/lambda.hpp> #include <boost/lambda/algorithm.hpp> #include <boost/lambda/bind.hpp> #include <boost/lambda/if.hpp> #include <boost/function.hpp> #include <functional> template< typename Key, typename Value, typename Predicate > std::map< Key, Value > copy_if( const std::map< Key, Value >& aMap, const Predicate& aPredicate) { using namespace std; using namespace boost::lambda; pair< typename map< Key, Value >::iterator, bool > (map< Key, Value >::*InsertFn)(const typename map< Key, Value >::value_type&) = &map< Key, Value >::insert; map<Key, Value > matchedObjects; for_each( aMap.begin(), aMap.end(), if_then( bind( aPredicate, _1), bind( InsertFn, &matchedObjects , bind( &make_pair< typename std::map < Key, Value >::key_type,typename map< Key, Value >::mapped_type >, bind(&map< Key, Value >::value_type::first, _1), bind(&map< Key, Value >::value_type::second,_1))))); return matchedObjects; } int main( int argc, char* argv[]) { std::map<std::string, std::string> objectsMap; objectsMap.insert(std::make_pair("one","value1")); objectsMap.insert(std::make_pair("two","value2")); objectsMap.insert(std::make_pair("three","value3")); boost::function< bool (std::map<std::string, std::string>::value_type)> mapPredicate = boost::lambda::bind(&std::map<std::string, std::string>::value_type::second,boost::lambda::_1) == "value3"; std::map<std::string, std::string> matchedObjectsMap = copy_if(objectsMap,mapPredicate); std::for_each( matchedObjectsMap.begin(), matchedObjectsMap.end(), std::cout << boost::lambda::bind(&std::map<std::string, std::string>::value_type::first, boost::lambda::_1) << boost::lambda::constant(" ") << boost::lambda::bind(&std::map<std::string, std::string>::value_type::second, boost::lambda::_1) << '\n'); return 0; } -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl