Hello, I am trying to serialize std containers via boost::serialization, but I am unable to get even simple code samples to compile. I used the serialization test_map.cpp as a guide to arrive at the very simple code that follows: --- snip --- #include <boost/serialization/map.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/nvp.hpp> #include <boost/archive/xml_oarchive.hpp> #include <iostream> #include <string> #include <map> int main() { std::map<std::string, std::string> data; data.insert(std::make_pair("a", "b")); data.insert(std::make_pair("b", "c")); data.insert(std::make_pair("c", "d")); boost::archive::xml_oarchive oa(std::cout); oa << boost::serialization::make_nvp("data", data); return 0; } --- snip --- Can anyone spot misuse above, or give me some clue as to why this won't compile? I am using boost 1.33.1, with GCC 4.1.1. If I change 'data' to be a simple string, serialization works, but if I use any std::container type (I've tried vector<string>, list<string>, and map<string,string> so far), I get an error of the following form: /usr/include/boost-1_33_1/boost/archive/detail/oserializer.hpp:131: error: invalid use of undefined type 'T3', where T1 = string T2 = list<T1> T3 = struct boost::serialization::extended_type_info_null<T2> /usr/include/boost-1_33_1/boost/serialization/type_info_implementation.hpp:26: error: declaration of 'T3', where T1 = string T2 = list<T1> T3 = struct boost::serialization::extended_type_info_null<T2> /usr/include/boost-1_33_1/boost/archive/detail/oserializer.hpp:132: error: invalid use of undefined type 'T3', where T1 = string T2 = list<T1> T3 = struct boost::serialization::extended_type_info_null<T2> /usr/include/boost-1_33_1/boost/serialization/type_info_implementation.hpp:26: error: declaration of 'T3', where T1 = string T2 = list<T1> T3 = struct boost::serialization::extended_type_info_null<T2> Any assistance would be greatly appreciated. - C.