Hi I am using custom archive classes. Problem is BOOST_CLASS_EXPORT_GUID is not working with the custom archive classes, i.e I am getting unregistered class exceptions all over the place, when saving derived class with base pointer. Here is link to my question http://boost.2283326.n4.nabble.com/BOOST-CLASS-EXPORT-GUID-with-custom-archi... about this. So I found other way for exporting the classes, i.e with archive register type. Exporting the classes with register_type is working well, no more unregistered_class exceptions, but probelm is it increase the compile times of my project by more than half. Project compile time with register_type is 40-45 minutes, and without 18-19 minutes. Here is how I am using the register_type : //RegisterMyTypes.h template<class Archive> void register_all_types(Archive&); //RegisterMyTypes.cpp #include "A.h" #include "B.h" // other classes includes template<class Archive> void register_all_types(Archive& a) { ar.register_type (); ar.register_type(); ..... all other classes which is maybe 100 } // explicit instiantion of all my archive classess template void register_all_types(XmlWOArchive& ar); template void register_all_types(XmlWIArchive& ar); template void register_all_types(DbgXmlWOArchive& ar); template void register_all_types(DbgXmlWIArchive& ar); template void register_all_types(BinaryOArchive& ar); template void register_all_types(BinaryIArchive& ar); template void register_all_types(CloneBinaryOArchive & ar); template void register_all_types(CloneBinaryIArchive & ar); template void register_all_types(DuplicateBinaryOArchive & ar); template void register_all_types(DuplicateBinaryIArchive & ar); I am calling register_all_types before doing the serialization/deserialization. And I am doing the serialization/deserialization in multiple functions in my project not just in one place, but this should not be problem, I mean I have the registration done only in one cpp file i.e RegisterMyTypes.cpp, so the templates should be instantiated only in this file, and it should be slow, right ? Thank you for any help -- View this message in context: http://boost.2283326.n4.nabble.com/serialization-slow-compile-times-with-arc... Sent from the Boost - Users mailing list archive at Nabble.com.