[Boost-users] Help with serializating an abstract object

I'm running into trouble handling an abstract object in my attempt to apply boost.serialization to my application. Since it doesn't have state, initially I didn't add serialize methods to this class, and got compilization errors for want of these methods. Next, I added noop methods, and got errors because the serialization package attempted to construct an abstract class. I see there is an is_abstract template, but don't know how to employ it. Can somebody give me some pointers? Note that I've choosen to implement non-templated serialize methods, using a forwared reference of the desired archive classes. Should this template be in the definition file, or implementation file (inside or outside the serialize method(s))?