[boost] Re: Re: Re: Re: Re: Re: [multi_index]announce:serializationsupport

From: Robert Ramey (ramey_at_[hidden])
Date: 2004-12-02 14:27:25

"Joaquín Mª López Muñoz" <joaquin_at_[hidden]> wrote in message
news:41AF68C7.B68D7CF4_at_tid.es...
> > Your original observation that the container de-serialization doesn't do
> > inplace construction is the source of the difficulty.  My interest would
be
> > to see this re-considered to see if its possible to use in-place
> > construction - similar to the way its done for most other pointer like
> > objects.  Somehow it doesn't seem that this should be all that hard.

> I'm pretty sure it is in fact impossible with the current functionality
> offered by Boost.Serialization. I'm saying this after thinking about the
issue
> for a good couple of weeks while designing multi_index serialization.
> The problem could be solved for std::lists:

> // load en alement into the list
> l.push_back(element_type());
> ar>>&li.back();

I remember now, this created problems for types without default
constructors.

>but this approach cannot be applied to associative containers like sets:
>one cannot just preinsert the element before loading the value, cause
>insertion *depends* on the value. It's a chicken and egg situation.

>IMHO this problem necessitates some facility to let the user
>fine-control tracking, in the spirit of the two features I proposed
>a few posts ago:

OK - I'm convinced.  I'm not motivated to change anything yet, but I can see
the problem.

>* reposition a track address
>* make_external for allowing tracking to an object which is not serialized
itself.

I can elaborate on how this could solve the problem, if you'd like.

feel free.

Robert Ramey