From: Jeff Garland (jeff_at_[hidden])
Date: 2004-04-19 12:34:40
On Mon, 19 Apr 2004 09:52:13 -0700, Robert Ramey wrote
> Jeff Garland wrote:
>
> > I believe that Matthew has now demonstrated that archive extension is
> > possible, which I believe is one of the major changes from the first
> > review. That said, any documentation of this process would clearly be a
> > plus. In a typical proprietary archives writing of the version and type
> > numbers will need to be shut off. So I can imagine documenting these
> > sorts of issues.
>
> As it turns out, type id, and object id are really required only for
> pointers and version is in fact optional.
>
> It would be possible to make an archive which:
>
> a) trapped (BOOST_STATIC_ASSERT) attempts to serialize a pointer
> b) trapped attempt to save/load object id and class id
> c) implemented null serialization of version numbers and trapped
> attempts to use version number != 0
>
> This would work only on serializations that had implementation
> attributes of no versioning, and no object tracking. If used on
> other types, it would trap at compiler time.
Excellent -- that's a clear advantage of this design over the typical virtual
function based approach.
> I believe that you would have what you wanted. In general, the part
> of the library which saves/loads the preamble is invoked only for
> pointers. An easy way to check this is to generate XML archive and
> find that there are not attributes for this types.
I suspected that this was the case -- nice to know the details :-)
Jeff