Thanks for your advice, Gennaro. I had to move the following includes to the beginning of the file: #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> I also realised that the following gives the same error of incomplete type: void SetOfRules::save(const string &fileName) // Save into a file { ofstream fout(fileName.c_str()); boost::archive::text_oarchive oa(fout); oa << *this; fout.close(); } I had to use a helper function like this: void _save(const SetOfRules &sor, const string &fileName); void SetOfRules::save(const string &fileName) // Save into a file { _save(*this,fileName); } void _save(const SetOfRules &sor, const string &fileName) { std::ofstream fout(fileName.c_str()); boost::archive::text_oarchive oa(fout); oa << sor; fout.close(); } // save And similarly to load a class. Diego

...

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.

I'm not too much into the latest gcc developments (certainly others will give a more accurate reply) but it looks like a two-phase lookup issue: at the time your function is parsed SetOfRules is actually incomplete, but the old gcc version you had didn't diagnose it and delayed analisys to instantiation time.

This is just my feeling. You might try moving SetOfRules' #include before.

--Gennaro.

-- 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