Re: [Boost-users] Serialization withpolymorphic_*_archiveandBOOST_CLASS_EXPORT

7 Nov 2006


      Anders Wang Kristensen wrote:
...
Thanks for your swift reply!
In my example with the non-templated serialize with
polymorphic_iarchive the statement BOOST_CLASS_EXPORT(B) fails to
compile. It compiles
fine without that statement, but fails to serialize with asserion:
Assertion failed: NULL != bpos_ptr, file
include\boost\archive\detail\oserializer.hpp, line 418
If I manully register B with register_type it works.
I'm using VC8 and boost 1.33.1 and I've attached the error message
from compiling.
-- Anders
Try the following:
...
...
int main(int argc, const char* argv[]){
   boost::shared_ptr<const A> a(new B); // Note "const"
   boost::shared_ptr<A> a1;
   std::stringstream ss;
  {
       boost::archive::polymorphic_text_oarchive oa(ss);
       //oa.template register_type<B>();
      oa << BOOST_SERIALIZATION_NVP(a);
   }
   try{
       boost::archive::polymorphic_text_iarchive ia(ss);
       //ia.template register_type<B>();
       ia >> BOOST_SERIALIZATION_NVP(a1);
   }
   catch(...){
       ...
   }
   B* x = dynamic_cast(a.get());
   B* y = dynamic_cast(b.get());
assert(*x == *y);
   return 0;
}
Also I strongly recommend you used templated serialize functions.

Robert Ramey
...
1>Compiling...
1>_main.cpp
1>include\boost\serialization\access.hpp(109) : error C2664: 'void
B::serialize(boost::archive::polymorphic_iarchive &,const unsigned
int)' : cannot convert parameter 1 from
'boost::archive::text_oarchive' to
'boost::archive::polymorphic_iarchive &' 1>
include\boost\serialization\serialization.hpp(81) : see reference to
function template instantiation 'void
boost::serialization::access::serialize(Archive &,T
&,const unsigned int)' being compiled 1>        with
1>        [
1>            Archive=boost::archive::text_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\serialization.hpp(140) : see
reference to function template instantiation 'void
boost::serialization::serialize(Archive &,T &,const
unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::text_oarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\oserializer.hpp(152) : see
reference to function template instantiation 'void
boost::serialization::serialize_adl(Archive &,T &,const
unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::text_oarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\oserializer.hpp(145) : while
compiling class template member function 'void
boost::archive::detail::oserializer::save_object_data(boost::archive::detail::basic_oarchive
&,const void *) const'
1>        with
1>        [
1>            Archive=boost::archive::text_oarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\oserializer.hpp(163) : see
reference to class template instantiation
'boost::archive::detail::oserializer' being compiled
1>        with
1>        [
1>            Archive=boost::archive::text_oarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\oserializer.hpp(162) : while
compiling class template member function 'const
boost::archive::detail::basic_oserializer
&boost::archive::detail::pointer_oserializer::get_basic_serializer(void)
const'
1>        with
1>        [
1>            T=B,
1>            Archive=boost::archive::text_oarchive
1>        ]
1>        include\boost\archive\detail\oserializer.hpp(515) : see
reference to class template instantiation
'boost::archive::detail::pointer_oserializer' being
compiled 1>        with
1>        [
1>            T=B,
1>            Archive=boost::archive::text_oarchive
1>        ]
1>        include\boost\serialization\export.hpp(86) : see reference
to function template instantiation 'const
boost::archive::detail::basic_pointer_oserializer
&boost::archive::detail::instantiate_pointer_oserializer(Archive
*,T *)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::text_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(82) : while
compiling class template member function 'void
boost::archive::detail::export_impl::archive::o::invoke(void)'
1>        with
1>        [
1>            Archive=boost::archive::text_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(105) : see reference
to class template instantiation
'boost::archive::detail::export_impl::archive::o' being
compiled 1>        with
1>        [
1>            Archive=boost::archive::text_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(89) : while
compiling class template member function 'void
boost::archive::detail::export_impl::archive::instantiate(void)'
1>        with
1>        [
1>            Archive=boost::archive::text_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(116) : see reference
to class template instantiation
'boost::archive::detail::export_impl::archive' being
compiled 1>        with
1>        [
1>            Archive=boost::archive::text_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(115) : while
compiling class template member function 'void
boost::archive::detail::export_impl::for_each_archive::instantiate(void)'
1>        with
1>        [
1>            ASeq=boost::archive::detail::known_archive_types::type,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(132) : see reference
to class template instantiation
'boost::archive::detail::export_impl::for_each_archive' being
compiled
1>        with
1>        [
1>            ASeq=boost::archive::detail::known_archive_types::type,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(131) : while
compiling class template member function
'boost::archive::detail::export_generator::export_generator(void)'
1>        with
1>        [
1>            T=B,
1>            ASeq=boost::archive::detail::known_archive_types::type
1>        ]
1>        include\boost\serialization\export.hpp(177) : see reference
to class template instantiation
'boost::archive::detail::export_generator' being compiled
1>        with
1>        [
1>            T=B,
1>            ASeq=boost::archive::detail::known_archive_types::type
1>        ]
1>        include\boost\serialization\export.hpp(176) : while
compiling class template member function 'const
boost::archive::detail::export_generator
*boost::archive::detail::export_instance::not_abstract::invoke(void)'
1>        with
1>        [
1>            T=B,
1>            ASeq=boost::archive::detail::known_archive_types::type
1>        ]
1>        include\boost\serialization\export.hpp(192) : see reference
to class template instantiation
'boost::archive::detail::export_instance::not_abstract' being
compiled
1>        with
1>        [
1>            T=B,
1>            ASeq=boost::archive::detail::known_archive_types::type
1>        ]
1>        include\boost\serialization\export.hpp(211) : see reference
to function template instantiation 'std::pair<_Ty1,_Ty2>
boost::archive::detail::export_instance_invoke(void)' being
compiled 1>        with
1>        [
1>            _Ty1=const
boost::archive::detail::export_generator
*,
1>            _Ty2=const boost::archive::detail::guid_initializer<B>
*, 1>            T=B,
1>            ASeq=boost::archive::detail::known_archive_types::type
1>        ]
1>        include\boost\serialization\export.hpp(210) : while
compiling class template member function 'std::pair<_Ty1,_Ty2>
boost::archive::detail::export_archives::non_empty_archive_list::invoke(void)'
1>        with
1>        [
1>            _Ty1=const
boost::archive::detail::export_generator
*,
1>            _Ty2=const boost::archive::detail::guid_initializer<B>
*, 1>            T=B,
1>            ASeq=boost::archive::detail::known_archive_types::type
1>        ]
1>        include\boost\serialization\export.hpp(225) : see reference
to class template instantiation
'boost::archive::detail::export_archives::non_empty_archive_list'
being compiled
1>        with
1>        [
1>            T=B,
1>            ASeq=boost::archive::detail::known_archive_types::type
1>        ]
1>
c:\users\awk\desktop\work\code\src\tests\scenegraph_regression\_main.cpp(129)
...
see reference to function template instantiation
'std::pair<_Ty1,_Ty2>
boost::archive::detail::export_archives_invoke(B
&,boost::archive::detail::known_archive_types::type &)' being compiled
1>        with
1>        [
1>            _Ty1=const
boost::archive::detail::export_generator
*,
1>            _Ty2=const boost::archive::detail::guid_initializer<B> *
1>        ]
1>include\boost\serialization\access.hpp(109) : error C2664: 'void
B::serialize(boost::archive::polymorphic_iarchive &,const unsigned
int)' : cannot convert parameter 1 from
'boost::archive::text_iarchive' to
'boost::archive::polymorphic_iarchive &' 1>
include\boost\serialization\serialization.hpp(81) : see reference to
function template instantiation 'void
boost::serialization::access::serialize(Archive &,T
&,const unsigned int)' being compiled 1>        with
1>        [
1>            Archive=boost::archive::text_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\serialization.hpp(140) : see
reference to function template instantiation 'void
boost::serialization::serialize(Archive &,T &,const
unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::text_iarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\iserializer.hpp(164) : see
reference to function template instantiation 'void
boost::serialization::serialize_adl(Archive &,T &,const
unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::text_iarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\iserializer.hpp(157) : while
compiling class template member function 'void
boost::archive::detail::iserializer::load_object_data(boost::archive::detail::basic_iarchive
&,void *,const unsigned int) const'
1>        with
1>        [
1>            Archive=boost::archive::text_iarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\iserializer.hpp(175) : see
reference to class template instantiation
'boost::archive::detail::iserializer' being compiled
1>        with
1>        [
1>            Archive=boost::archive::text_iarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\iserializer.hpp(174) : while
compiling class template member function 'const
boost::archive::detail::basic_iserializer
&boost::archive::detail::pointer_iserializer::get_basic_serializer(void)
const'
1>        with
1>        [
1>            T=B,
1>            Archive=boost::archive::text_iarchive
1>        ]
1>        include\boost\archive\detail\iserializer.hpp(546) : see
reference to class template instantiation
'boost::archive::detail::pointer_iserializer' being
compiled 1>        with
1>        [
1>            T=B,
1>            Archive=boost::archive::text_iarchive
1>        ]
1>        include\boost\serialization\export.hpp(78) : see reference
to function template instantiation 'const
boost::archive::detail::basic_pointer_iserializer
&boost::archive::detail::instantiate_pointer_iserializer(Archive
*,T *)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::text_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(74) : while
compiling class template member function 'void
boost::archive::detail::export_impl::archive::i::invoke(void)'
1>        with
1>        [
1>            Archive=boost::archive::text_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(105) : see reference
to class template instantiation
'boost::archive::detail::export_impl::archive::i' being
compiled 1>        with
1>        [
1>            Archive=boost::archive::text_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(89) : while
compiling class template member function 'void
boost::archive::detail::export_impl::archive::instantiate(void)'
1>        with
1>        [
1>            Archive=boost::archive::text_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(116) : see reference
to class template instantiation
'boost::archive::detail::export_impl::archive' being
compiled 1>        with
1>        [
1>            Archive=boost::archive::text_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(115) : while
compiling class template member function 'void
boost::archive::detail::export_impl::for_each_archive::instantiate(void)'
1>        with
1>        [
1>
ASeq=boost::mpl::list5boost::archive::text_iarchive,boost::archive::xml_oarchive,boost::archive::x...,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(122) : see reference
to class template instantiation
'boost::archive::detail::export_impl::for_each_archive' being
compiled
1>        with
1>        [
1>
ASeq=boost::mpl::list5boost::archive::text_iarchive,boost::archive::xml_oarchive,boost::archive::x...,
1>            T=B
1>        ]
1>include\boost\serialization\access.hpp(109) : error C2664: 'void
B::serialize(boost::archive::polymorphic_iarchive &,const unsigned
int)' : cannot convert parameter 1 from
'boost::archive::xml_oarchive' to
'boost::archive::polymorphic_iarchive &' 1>
include\boost\serialization\serialization.hpp(81) : see reference to
function template instantiation 'void
boost::serialization::access::serialize(Archive &,T
&,const unsigned int)' being compiled 1>        with
1>        [
1>            Archive=boost::archive::xml_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\serialization.hpp(140) : see
reference to function template instantiation 'void
boost::serialization::serialize(Archive &,T &,const
unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::xml_oarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\oserializer.hpp(152) : see
reference to function template instantiation 'void
boost::serialization::serialize_adl(Archive &,T &,const
unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::xml_oarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\oserializer.hpp(145) : while
compiling class template member function 'void
boost::archive::detail::oserializer::save_object_data(boost::archive::detail::basic_oarchive
&,const void *) const'
1>        with
1>        [
1>            Archive=boost::archive::xml_oarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\oserializer.hpp(163) : see
reference to class template instantiation
'boost::archive::detail::oserializer' being compiled
1>        with
1>        [
1>            Archive=boost::archive::xml_oarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\oserializer.hpp(162) : while
compiling class template member function 'const
boost::archive::detail::basic_oserializer
&boost::archive::detail::pointer_oserializer::get_basic_serializer(void)
const'
1>        with
1>        [
1>            T=B,
1>            Archive=boost::archive::xml_oarchive
1>        ]
1>        include\boost\archive\detail\oserializer.hpp(515) : see
reference to class template instantiation
'boost::archive::detail::pointer_oserializer' being
compiled 1>        with
1>        [
1>            T=B,
1>            Archive=boost::archive::xml_oarchive
1>        ]
1>        include\boost\serialization\export.hpp(86) : see reference
to function template instantiation 'const
boost::archive::detail::basic_pointer_oserializer
&boost::archive::detail::instantiate_pointer_oserializer(Archive
*,T *)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::xml_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(82) : while
compiling class template member function 'void
boost::archive::detail::export_impl::archive::o::invoke(void)'
1>        with
1>        [
1>            Archive=boost::archive::xml_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(105) : see reference
to class template instantiation
'boost::archive::detail::export_impl::archive::o' being
compiled 1>        with
1>        [
1>            Archive=boost::archive::xml_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(89) : while
compiling class template member function 'void
boost::archive::detail::export_impl::archive::instantiate(void)'
1>        with
1>        [
1>            Archive=boost::archive::xml_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(116) : see reference
to class template instantiation
'boost::archive::detail::export_impl::archive' being
compiled 1>        with
1>        [
1>            Archive=boost::archive::xml_oarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(115) : while
compiling class template member function 'void
boost::archive::detail::export_impl::for_each_archive::instantiate(void)'
1>        with
1>        [
1>
ASeq=boost::mpl::list4boost::archive::xml_oarchive,boost::archive::xml_iarchive,boost::archive::po...,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(122) : see reference
to class template instantiation
'boost::archive::detail::export_impl::for_each_archive' being
compiled
1>        with
1>        [
1>
ASeq=boost::mpl::list4boost::archive::xml_oarchive,boost::archive::xml_iarchive,boost::archive::po...,
1>            T=B
1>        ]
1>include\boost\serialization\access.hpp(109) : error C2664: 'void
B::serialize(boost::archive::polymorphic_iarchive &,const unsigned
int)' : cannot convert parameter 1 from
'boost::archive::xml_iarchive' to
'boost::archive::polymorphic_iarchive &' 1>
include\boost\serialization\serialization.hpp(81) : see reference to
function template instantiation 'void
boost::serialization::access::serialize(Archive &,T
&,const unsigned int)' being compiled 1>        with
1>        [
1>            Archive=boost::archive::xml_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\serialization.hpp(140) : see
reference to function template instantiation 'void
boost::serialization::serialize(Archive &,T &,const
unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::xml_iarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\iserializer.hpp(164) : see
reference to function template instantiation 'void
boost::serialization::serialize_adl(Archive &,T &,const
unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::xml_iarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\iserializer.hpp(157) : while
compiling class template member function 'void
boost::archive::detail::iserializer::load_object_data(boost::archive::detail::basic_iarchive
&,void *,const unsigned int) const'
1>        with
1>        [
1>            Archive=boost::archive::xml_iarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\iserializer.hpp(175) : see
reference to class template instantiation
'boost::archive::detail::iserializer' being compiled
1>        with
1>        [
1>            Archive=boost::archive::xml_iarchive,
1>            T=B
1>        ]
1>        include\boost\archive\detail\iserializer.hpp(174) : while
compiling class template member function 'const
boost::archive::detail::basic_iserializer
&boost::archive::detail::pointer_iserializer::get_basic_serializer(void)
const'
1>        with
1>        [
1>            T=B,
1>            Archive=boost::archive::xml_iarchive
1>        ]
1>        include\boost\archive\detail\iserializer.hpp(546) : see
reference to class template instantiation
'boost::archive::detail::pointer_iserializer' being
compiled 1>        with
1>        [
1>            T=B,
1>            Archive=boost::archive::xml_iarchive
1>        ]
1>        include\boost\serialization\export.hpp(78) : see reference
to function template instantiation 'const
boost::archive::detail::basic_pointer_iserializer
&boost::archive::detail::instantiate_pointer_iserializer(Archive
*,T *)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::xml_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(74) : while
compiling class template member function 'void
boost::archive::detail::export_impl::archive::i::invoke(void)'
1>        with
1>        [
1>            Archive=boost::archive::xml_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(105) : see reference
to class template instantiation
'boost::archive::detail::export_impl::archive::i' being
compiled 1>        with
1>        [
1>            Archive=boost::archive::xml_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(89) : while
compiling class template member function 'void
boost::archive::detail::export_impl::archive::instantiate(void)'
1>        with
1>        [
1>            Archive=boost::archive::xml_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(116) : see reference
to class template instantiation
'boost::archive::detail::export_impl::archive' being
compiled 1>        with
1>        [
1>            Archive=boost::archive::xml_iarchive,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(115) : while
compiling class template member function 'void
boost::archive::detail::export_impl::for_each_archive::instantiate(void)'
1>        with
1>        [
1>
ASeq=boost::mpl::list3boost::archive::xml_iarchive,boost::archive::polymorphic_oarchive,boost::arc...,
1>            T=B
1>        ]
1>        include\boost\serialization\export.hpp(122) : see reference
to class template instantiation
'boost::archive::detail::export_impl::for_each_archive' being
compiled
1>        with
1>        [
1>
ASeq=boost::mpl::list3boost::archive::xml_iarchive,boost::archive::polymorphic_oarchive,boost::arc...,
1>            T=B
1>        ]
----- Original Message -----
From: "Robert Ramey" 
Newsgroups: gmane.comp.lib.boost.user
Sent: Tuesday, November 07, 2006 2:42 AM
Subject: Re: Serialization with
polymorphic_*_archiveandBOOST_CLASS_EXPORT
...
Anders Wang Kristensen wrote:
...
Hi,
I'm having trouble serializing through the a pointer to the base as
shown below.
If I manually register class B with template register_type<B>() it
works, but I
would rather use the BOOST_CLASS_EXPORT macros since that is more
convenient.
Unfortunately BOOST_CLASS_EXPORT  assumes you are using the
templated version of serialize, and not
polymorphic_iarchive/oarchive, that I'm using.
I don't think that's true. Maybe you mean it assums you are using
member serialize functions - but that won't be true either.
Basically I think your example should function.  Where does it fail?
Does it throw and exception? where? does the assert fail?, etc.,etc.
Also what compiler, os, version of boost etc.?
Though its beside the point, I would also make your example more
portable wit the fillowing
changes:
...
struct A {
   template<class Archive>
   void serialize(Archive & ar, const unsigned int file_version);
   ...
};
template<class Archive>
void A::serialize(Archive & ar, const unsigned int file_version){
   ar & BOOST_SERIALIZATION_NVP(data);
}
struct B : public A {
   template<class Archive>
   void serialize(Archive & ar, const unsigned int file_version);
   ...
};
template<class Archive>
void B::serialize(Archive & ar, const unsigned int file_version){
   ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(A);
   ar & BOOST_SERIALIZATION_NVP(foo);
}
BOOST_CLASS_EXPORT(B)
int main(int argc, const char* argv[]){
   boost::shared_ptr<A> a(new B);
   boost::shared_ptr<A> a1;
   std::stringstream ss;
  {
       boost::archive::polymorphic_text_oarchive oa(ss);
       //oa.template register_type<B>();
      oa << BOOST_SERIALIZATION_NVP(a);
   }
   try{
       boost::archive::polymorphic_text_iarchive ia(ss);
       //ia.template register_type<B>();
       ia >> BOOST_SERIALIZATION_NVP(a1);
   }
   catch(...){
       ...
   }
   B* x = dynamic_cast(a.get());
   B* y = dynamic_cast(b.get());
assert(*x == *y);
   return 0;
}
----- Original Message -----
From: "Robert Ramey" 
Newsgroups: gmane.comp.lib.boost.user
Sent: Tuesday, November 07, 2006 2:42 AM
Subject: Re: Serialization with
polymorphic_*_archiveandBOOST_CLASS_EXPORT
...
Anders Wang Kristensen wrote:
...
Hi,
I'm having trouble serializing through the a pointer to the base as
shown below.
If I manually register class B with template register_type<B>() it
works, but I
would rather use the BOOST_CLASS_EXPORT macros since that is more
convenient.
Unfortunately BOOST_CLASS_EXPORT  assumes you are using the
templated version of serialize, and not
polymorphic_iarchive/oarchive, that I'm using.
I don't think that's true. Maybe you mean it assums you are using
member serialize functions - but that won't be true either.
Basically I think your example should function.  Where does it fail?
Does it throw and exception? where? does the assert fail?, etc.,etc.
Also what compiler, os, version of boost etc.?
Though its beside the point, I would also make your example more
portable wit the fillowing
changes:
...
struct A {
   template<class Archive>
   void serialize(Archive & ar, const unsigned int file_version);
   ...
};
template<class Archive>
void A::serialize(Archive & ar, const unsigned int file_version){
   ar & BOOST_SERIALIZATION_NVP(data);
}
struct B : public A {
   template<class Archive>
   void serialize(Archive & ar, const unsigned int file_version);
   ...
};
template<class Archive>
void B::serialize(Archive & ar, const unsigned int file_version){
   ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(A);
   ar & BOOST_SERIALIZATION_NVP(foo);
}
BOOST_CLASS_EXPORT(B)
int main(int argc, const char* argv[]){
   boost::shared_ptr<A> a(new B);
   boost::shared_ptr<A> a1;
   std::stringstream ss;
  {
       boost::archive::polymorphic_text_oarchive oa(ss);
       //oa.template register_type<B>();
      oa << BOOST_SERIALIZATION_NVP(a);
   }
   try{
       boost::archive::polymorphic_text_iarchive ia(ss);
       //ia.template register_type<B>();
       ia >> BOOST_SERIALIZATION_NVP(a1);
   }
   catch(...){
       ...
   }
   B* x = dynamic_cast(a.get());
   B* y = dynamic_cast(b.get());
assert(*x == *y);
   return 0;
}