Hello, I have an error that is puzzling me. I have defined serialization of several custom classes, and everything worked perfectly until we've changed to a new Linux OS and had to reinstall Boost. Now the program doesn't compile and the error given is: error: incomplete type 'boost::serialization::extended_type_info_null<SetOfRules>' used in nested name specifier I don't really understand why it says there is an incomplete type when there used to be no errors. The same error happens with all the classes where I've defined serialization. The offending code for the above error message is: void save(const SetOfRules &sor, const string &fileName) { std::ofstream fout(fileName.c_str()); boost::archive::text_oarchive oa(fout); oa << sor; // <== Here is the error fout.close(); } // save Currently I'm using gcc version 4.0.4 20060507 (prerelease) (Debian 4.0.3-3) Can anybody help? Diego -- Do you want to know what is going on in Language Technology in Australia and New Zealand? Join ALTA -- http://www.alta.asn.au/ This message is intended for the addressee named and may contain confidential information. If you are not the intended recipient, please delete it and notify the sender. Views expressed in this message are those of the individual sender, and are not necessarily the views of Macquarie University. --------------------------------------------------------------------- Diego MOLLA ALIOD diego@ics.mq.edu.au Department of Computing http://www.ics.mq.edu.au/~diego Macquarie University