The classes that I am trying to serialize all have private destructors (and constructors - they are intended to be accessed through a factory function that returns a smart pointer). Is there any way serialize such classes beyond modifying the headers of these classes (I don't have the source) to include "friend class boost::serialization::access;"? Marcin Tustin IT Innovation Centre 2 Venture Road Chilworth Science Park Southampton, SO16 7NP, UK tel: +44 23 8076 0834 fax: +44 23 8076 0833 mailto:mt@it-innovation.soton.ac.uk http://www.it-innovation.soton.ac.uk