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From: Eric (eric-public_at_[hidden])
Date: 2005-05-30 13:33:21

Hi Robert (and Jeff):

> Actually, the export.hpp has to come after any *archive.hpp
> due to the "trick" used to instantiate the appropriate code.

That was the problem! I only used the xml_oarchive object in the main()
function, so I only included the respective headers in the main. The rest
of the code included the export.hpp header. So, I changed my common include
file to also include the *archive.hpp headers and everything is working

The only thing that I've noticed is that sometimes the objects won't be
found when I have 2 or more abstract classes between the base and the final
concrete object. The concrete object is registered, but it looks like the
(Derived,Base) pair isn't being found. Any advice on where I went wrong on
that is appreciated. In the meantime, I'm using void_cast_register<>(...)
to register the base class and the top derived class and everything works
great so far :)


> On some compilers, one can get multiple symbol errors. I
> think the only way to handle this is to be sure its
> included at most once or tweak the linker switches to
> override the error.

> Robert Ramey

>> "Eric" <eric-public_at_[hidden]> wrote in
>> message news:001601c564d9$35709a60$0a00a8c0_at_FASTBRICK...
>> Thanks Robert. This partially worked... Your
>> comment about putting the BOOST_CLASS_EXPORT
>> macro into the header keyed me into something.

>> I am using the BOOST_CLASS_EXPORT(derived) macro, but
>> I've been placing them into the source (cpp) file instead
>> of the header (h) file. With my system, when I put
>> BOOST_CLASS_EXPORT(derived) into the header file, I
>> get a multiply-defined error at link time (the offending
>> code is boost::archive::detail::guid_initializer<class,...>
>> since the header is included multiple times when I use the
>> class.
>> As a test, I setup a sandbox with a stripped down system
>> and was able to get it to work when I put the
>> BOOST_CLASS_EXPORT in the header, but not when it is
>> in the cpp file.
>> Q: Why does the location of the BOOST_CLASS_EXPORT
>> matter? Is it doing order-depended initialization
>> upon bringing up the system?
>> Q: How do I avoid the mutiple defined error in
>> the linker?
>> Thanks again for your help and the library :)
>> -Eric

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