Hi, I am using the boost serialization library in a personal project and ran into a recursive include problem. Class A serialize an object of class B and class B also serialize an object of class A. So class A must be a complete type in class B and class B must be a complete type in class A, hence the recursive include problem. A easy way to fix this would be to put the serialization code in the source file instead of the header file but I can't get this to work... I always end up with unresolved externals if the body of my serialization functions are not within the header file. Any way around this beside switching to non-intrusive serialization? thanx! -- Frédérick Martel-Lupien Étudiant en Génie Informatique Université de Sherbrooke fred.lupien@gmail.com