Hello, I have a problem reading back serialization archives generated by older version of boost. I used to have a YYYYMMDD class versioning scheme. This broke with boost 1.42, which truncates the class version numbers to 16 bits, causing my code to generated corrupted archives. I fixed my code by implementing my own class versioning when compiling with boost 1.42, so I am again able to create archives that I can read back. Unfortunately this fixes only half of the problem. How can I read back archives that were saved using older releases of the serialization library? I saw that someone else opened ticket 3990 for the same problem. Here you suggested using the function get_library_version() in the following way: template<class Archive> void serialization(Archive & ar, unsigned int version){ library_version_type library_version = get_library_version if(library_version < 6) // the library version is a date my_date = version; else{ // don't use the boost serialization number, use ours instead ar & my_date; } ar && old_data_items if(ar.is_loading) if(my_date > "jan 10, 2010") ar & new_data_item; but I can't get this to work: the version argument is already truncated, and can't be interpreted as a date. As the bug reporter said, this is a case of data loss. Should I reopen ticket 3990, or is this code supposed to work with svn (I admit I did not test the trunk)? Thanks for your help, David.