I am using boost 1.32. When I serialize a string, no metadata is written, as implementation_level<string> is set to primitive_type in serialization/string.hpp. However, when I serialize a vector<string>, I end up with metadata, because implementation_level<vector<string> > is not set anywhere and therefore defaults to object_class_info. Every other primitive type appears to be covered by BOOST_SERIALIZATION_COLLECTION_TRAITS and therefore implementation_level<vector<T> > is object_serializable for every other primitive type. I checked in 1.33 and there don't appear to be any relevant changes, but I could be wrong. My question: is this an omission; that is, should implementation_level<vector<string> > be object_serializable? (And similarly for other collections of strings.) Thanks, Ben -- If this message helped you, consider buying an item from my wish list: <http://artins.org/ben/wishlist> I changed my name: <http://periodic-kingdom.org/People/NameChange.php>