Re: [Boost-users] serialization: loading std::map replaces existing mapdata objects

From: Peter Whaite (boost_at_[hidden])
Date: 2005-12-12 17:38:06

Robert Ramey <ramey_at_[hidden]> wrote:
> the copy_collection was an experiment on work has been suspended and
> probably not be implemented, and if it were implemented, would be
> implemented differently in anycase.

Ok. Thanks.

> b) Just specify a serialize function for the particular map you are
>    using.
> e.g.
> 
> template<class Archive>
> void serialize(Archive & ar, std::map<my_class> > & t, const unsigned int 
> version){
>     // for each member in the map
>          ar & *it;
> }
> 
> I believe that b) would be a good solution for you.

Yes thats ok, but I was serializing more than one map in the same class
and I wanted to maintain the separation in xml.  I guess I'd have to
derive my own map I lazily trying to avoid that.

> You post clarifies one point in particular.  My version implements the
> most commonly desired behavior - but not the only behavior people
> might want.  In other words - there is not always agreeement on what
> it means to "restore" something. And in fact the serialization
> implementation uses both and some time its confusing.

Yes I agree, though in my case, now I know the limitation, its not
difficult to refactor.  I do find the refactoring (conditionally
initialize after a load) a little forced however.

Thanks again for the response.

--
Peter Whaite.