Any ideas? The only options I can come up with are: 1) break the pimpl idiom by removing the opaqueness or implementing private getter/setter functions for the serialize template. Still get the exception safety of using the pimpl but lose the compile-time decoupling. 2) only implement the serialize function for certain types of archives. This one seems the most interesting actually. 3) write string writers/parsers for serialize to use, which pretty much destroys the whole point of using boost::serialization in the first place. Maybe I'm missing a good option?