Re: [Boost-users] serialization: curious un-serializing issue RFI

From: Hugh Hoover (hugh_at_[hidden])
Date: 2007-10-29 18:15:14

more info:

On Oct 27, 2007, at 3:36 PM, Hugh Hoover wrote:

> I have a curious problem that's just sprung up, after changing from
> using plain-old-pointers to using boost::shared_ptrs internally in my
> data structures (stl hash_map and map)
> The problem is that while the XML archive works correctly, both text
> and binary fail (they all used to work).
>
> This is using gcc 4.0.1 on darwin and VC8 on windows, boost version is
> 1.34.1
>
> The failure occurs while unserializing an archive, specifically when
> trying to read back a shared_ptr to an already unserialized object.
> In the archive, it shows the object (pointer) as an object_reference
> (the same reference id in XML and text).  While the XML version reads
> the pointer back correctly, the text version fails and returns NULL.
> I have not determined the exact reason why the text version fails (it
> doesn't throw, just returns NULL).  The serialization does not appear
> to have any problems.

The proximate cause of the problem is in void_upcast, which does not
find a pre-registered pair of types matching the base and derived types
passed in from load_pointer_type::invoke.  I'm having a hard time
understanding how that could be...  I've called void_cast_register for
the type pair, so it SHOULD be registered - and the xml_iarchive was
able to reconstruct the object properly.

Any suggestions?