[boost] Re:[serialization] serialization and pimpl

From: Robert Ramey (ramey_at_[hidden])
Date: 2003-10-24 12:01:06

Vladimir Prus worte

>Robert Ramey wrote:
>> Note that I personally have no plans to write such a
>> virtual_archive but I would be pleased to support
>> anyone who wants to.   I believe the system would
>> currently support the construction of such a virtual
>> archive with not changes to the current code.

>I seems possible. The 'virtual_archive' will call virtual functions for
>saving built-in types and serialization::save for all the rest? Is the
>"vsave" family of method what you have in mind?

That wouldn't be the right spot.  Those functions are to provide
a virtual interfarce for certain "built-in" types like object -id etc.

I'm reluctant to speculate on this but will do anyway as I love
to talk.

I'm guesssing that there would be:

class virtual_sarchive_interface {
        virtual void save(int t) = 0;
        virtual void save(float t) = 0;
        ...
};

then there would be

class virtual_text_iarchive : 
        public common<virtual_text_iarchive>, virtual_iarchive_interface
{
        virtual void save(int t){
                is << t;
        }
        ...
};

A plugin would be compiled against the first class - virtual_archive_interface.
so it would use

class plug-in {
        void serialize(virtual_iarchive_interface & ar, const unsigned int file_version){
                ....
        }
}

The main program would include the plugin header but create 
a virtual_text_archive. Then

ar << t

resolve to the the proper function through the vtable of the virtual_iarchive_interface.

This is basically the way Microsoft COM works for plug-ins.  It would not
entail changing anything done to date.

There is no way I'm going to do this.

Robert Ramey