Dear group, I am working with a observer pattern in a simulator and would like to restore the simulators state. This means that I need to restore the pointers to the observers in the subject. My simple example contains a composite that holds pointers to base class of the observers. The observable hold one of the observers using a base class pointer. The save part is OK but when I introduce restore I get compile time errors. Compiling (dbg) main.cpp obj/main.o /home/ecarmik/boost/include/boost-1_39/boost/archive/detail/iserializer.hpp: In function 'void boost::archive::load(Archive&, const T&) [with Archive = boost::archive::text_iarchive, T = composite]': /home/ecarmik/boost/include/boost-1_39/boost/archive/detail/common_iarchive.hpp:59: instantiated from 'void boost::archive::detail::common_iarchive<Archive>::load_override(T&, int) [with T = const composite, Archive = boost::archive::text_iarchive]' /home/ecarmik/boost/include/boost-1_39/boost/archive/basic_text_iarchive.hpp:62: instantiated from 'void boost::archive::basic_text_iarchive<Archive>::load_override(T&, int) [with T = const composite, Archive = boost::archive::text_iarchive]' /home/ecarmik/boost/include/boost-1_39/boost/archive/text_iarchive.hpp:65: instantiated from 'void boost::archive::text_iarchive_impl<Archive>::load_override(T&, int) [with T = const composite, Archive = boost::archive::text_iarchive]' /home/ecarmik/boost/include/boost-1_39/boost/archive/detail/interface_iarchive.hpp:61: instantiated from 'Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = const composite, Archive = boost::archive::text_iarchive]' main.cpp:24: instantiated from here /home/ecarmik/boost/include/boost-1_39/boost/archive/detail/iserializer.hpp:560: error: no matching function for call to 'load_wrapper(boost::archive::text_iarchive&, const composite&, boost::serialization::is_wrapper<composite>)' make: *** [obj/main.o] Error 1 Is it possible to re-create objects during restore from file. Please note that composite class only contains base class pointers. Do I need to create a separate load to do this with constructors? Where can I read about this or even better, find an example? Please find the files included. / Mikael