Hi, all A member of a target class, where one STL object (map) includes another (set), prevent the code from being built properly and the error message urges me to implement *serialize* method for pair<string*, set<unsigned>>. What is the typical way of implementing serialization using boost for this kind of data structures? * Code snippet class B { … map<const string*, set<unsigned> > lines; .. template<class Archive> void serialize (Archive & ar, const unsigned int version) { ar & lines; … * Build error message /opt/local/include/boost/serialization/access.hpp:118: error: ‘class std::map<const std::string*, std::set<unsigned int, std::less<unsigned int>, std::allocator<unsigned int> >, std::less<const std::string*>, std::allocator<std::pair<const std::string* const, std::set<unsigned int, std::less<unsigned int>, std::allocator<unsigned int> > > > >’ has no member named ‘serialize’ Thanks for your help in advance, /Kangkook