[boost] [serialization] serialization and pimpl

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-10-23 09:22:19

I'm completely at loss how to serialize classes which use the pimpl idiom. 
What I have is:

    class BlockFormula {
    public:
        [snip]
    private:
        struct data;
        boost::scoped_ptr<data> m_data;        
    };

The "data" class is defined in cpp file. I can't write serialization method of 
the form:

    template<class Archive>
    void serialize(Archive& ar, unsigned version)
    {
        ar & *m_data;
    }

since "data" is incomplete type at the point where this "serialization" is 
seen. I'd rather not hardcode the type of archieve, as in

    void serialize(boost::archive::text_oarchive& ar, unsigned version);
    // definition in cpp file, where "data" definition is visible.

So, what's the solution?

TIA,
Volodya