Here is an example of the described behaviour Here, it does not compile with non modified composite_key.hpp file, and do compile with modified file. Regards, Mathieu Peyréga ----------------------------- test_multi_index.cpp ----------------------------- #include <string> #include <boost/multi_index_container.hpp> #include <boost/multi_index/tag.hpp> #include <boost/multi_index/indexed_by.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/composite_key.hpp> using namespace boost; using namespace boost::multi_index; class GPS_Station { public: GPS_Station(void); GPS_Station(GPS_Station const& station); GPS_Station& operator=(GPS_Station const& station); ~GPS_Station(void); unsigned long m_Id; std::string m_Name; std::string m_DomeNumber; double m_Epoch; double m_X_ECEF; double m_Y_ECEF; double m_Z_ECEF; }; class CTestMultiIndex { public: // Tags pour l'utilisation du multi-index container de Boost en mode "Tag" typedef composite_key<GPS_Station, member<GPS_Station,unsigned long,&GPS_Station::m_Id>, member<GPS_Station,double,&GPS_Station::m_Epoch> > by_id_and_epoch; typedef composite_key<GPS_Station, member<GPS_Station,unsigned long,&GPS_Station::m_Id>, member<GPS_Station,double,&GPS_Station::m_Epoch> > by_id_and_epoch; typedef composite_key<GPS_Station, member<GPS_Station,std::string,&GPS_Station::m_Name>, member<GPS_Station,double,&GPS_Station::m_Epoch> > by_name_and_epoch; typedef composite_key<GPS_Station, member<GPS_Station,std::string,&GPS_Station::m_DomeNumber>, member<GPS_Station,double,&GPS_Station::m_Epoch> > by_domenumber_and_epoch; typedef composite_key<GPS_Station, member<GPS_Station,double,&GPS_Station::m_Epoch>, member<GPS_Station,unsigned long,&GPS_Station::m_Id> > by_epoch_and_id; typedef composite_key<GPS_Station, member<GPS_Station,double,&GPS_Station::m_Epoch>, member<GPS_Station,std::string,&GPS_Station::m_Name> > by_epoch_and_name; typedef composite_key<GPS_Station, member<GPS_Station,double,&GPS_Station::m_Epoch>, member<GPS_Station,std::string,&GPS_Station::m_DomeNumber> > by_epoch_and_domenumber; typedef multi_index_container<GPS_Station, indexed_by<ordered_non_unique<by_id_and_epoch>, ordered_non_unique<by_name_and_epoch>, ordered_non_unique<by_domenumber_and_epoch>, ordered_unique<by_epoch_and_id>, ordered_unique<by_epoch_and_name>, ordered_unique<by_epoch_and_domenumber> > > DataSetType; typedef nth_index<DataSetType,0>::type dataset_by_id_and_epoch; typedef nth_index<DataSetType,1>::type dataset_by_name_and_epoch; typedef nth_index<DataSetType,2>::type dataset_by_domenumber_and_epoch; typedef nth_index<DataSetType,3>::type dataset_by_epoch_and_id; typedef nth_index<DataSetType,4>::type dataset_by_epoch_and_name; typedef nth_index<DataSetType,5>::type dataset_by_epoch_and_domenumber; void fail_to_compile(DataSetType& dataset, std::string const& stationname, std::string const& prefix); }; // class CTestMultiIndex void CTestMultiIndex::fail_to_compile(DataSetType& dataset, std::string const& stationname, std::string const& prefix) { const dataset_by_name_and_epoch &datasetbynameandepoch = get<1>(dataset); std::pair<dataset_by_name_and_epoch::iterator, dataset_by_name_and_epoch::iterator> range = datasetbynameandepoch.equal_range(stationname); }