Re: [Boost-users] serialization: loading std::map replaces existingmapdata objects

From: Peter Whaite (boost_at_[hidden])
Date: 2005-12-14 14:43:32

Robert Ramey <ramey_at_[hidden]> wrote:

> Oh then maybe you want:

> void serialize(boost::archive::xml_iarchive & ar, std::map<my_class> > & t, 
> const
> unsigned int version){
>     // for each member in the map
>          ar & *it;
> }

Ah, I was looking for that but missed it.  I'm having trouble compiling
the load though as gcc doesnt like the map member's std::pair.first being
const. I'm sure I'm doing something incorrect that's blindingly obvious,
but I just can't see it.  The code and compiler messages are below.

#include <map>
#include <fstream>
#include <boost/archive/xml_wiarchive.hpp>
#include <boost/serialization/utility.hpp> // For std::pair

typedef boost::archive::xml_wiarchive iarchive;
typedef std::wifstream ifstream;

struct Mark {};
enum MarkId {low,median,high};
typedef std::map<MarkId,Mark> MarkMap;

void serialize(iarchive &ar, MarkMap & m, const unsigned int version)
{
    MarkMap::iterator it;
    for (it = m.begin() ; it != m.end(); ++it) {
        ar & boost::serialization::make_nvp("item", *it);
    }
}

int main(int argc, char* argv[])
{
   ifstream ifs;
   iarchive ar(ifs);
   MarkMap marks;
   ar >> boost::serialization::make_nvp("marks",marks);
}

gcc --version
gcc (GCC) 3.2.2 20030222 (Red Hat Linux 3.2.2-5)

g++ -c tsrz.cpp -I/usr/local/include  -isystem /usr/local/include/boost-1_33 -isystem ./boost -g -Wall -Wno-non-virtual-dtor -Wno-inline -ftemplate-depth-255 -finline-functions -MMD -MF.deps/tsrz.d
/usr/local/include/boost-1_33/boost/archive/detail/iserializer.hpp: In function 
   `void boost::archive::load(Archive&, T&) [with Archive = 
   boost::archive::xml_wiarchive, T = const MarkId]':
/usr/local/include/boost-1_33/boost/archive/basic_xml_iarchive.hpp:80:   instantiated from `void boost::archive::basic_xml_iarchive<Archive>::load_override(const boost::serialization::nvp<T>&, int) [with T = const MarkId, Archive = boost::archive::xml_wiarchive]'
/usr/local/include/boost-1_33/boost/archive/xml_wiarchive.hpp:78:   instantiated from `void boost::archive::xml_wiarchive_impl<Archive>::load_override(T&, int) [with T = const boost::serialization::nvp<const MarkId>, Archive = boost::archive::xml_wiarchive]'
/usr/local/include/boost-1_33/boost/archive/detail/interface_iarchive.hpp:84:   instantiated from `Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = const boost::serialization::nvp<const MarkId>, Archive = boost::archive::xml_wiarchive]'
/usr/local/include/boost-1_33/boost/archive/detail/interface_iarchive.hpp:91:   instantiated from `Archive& boost::archive::detail::interface_iarchive<Archive>::operator&(T&) [with T = const boost::serialization::nvp<const MarkId>, Archive = boost::archive::xml_wiarchive]'
/usr/local/include/boost-1_33/boost/serialization/utility.hpp:43:   instantiated from `void boost::serialization::serialize(Archive&, std::pair<F, S>&, unsigned int) [with Archive = boost::archive::xml_wiarchive, F = const MarkId, S = Mark]'
/usr/local/include/boost-1_33/boost/serialization/serialization.hpp:140:   instantiated from `void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::archive::xml_wiarchive, T = std::pair<const MarkId, Mark>]'
/usr/local/include/boost-1_33/boost/archive/detail/iserializer.hpp:158:   instantiated from `void boost::archive::detail::iserializer<Archive, T>::load_object_data(boost::archive::detail::basic_iarchive&, void*, unsigned int) const [with Archive = boost::archive::xml_wiarchive, T = std::pair<const MarkId, Mark>]'
/usr/local/include/boost-1_33/boost/mpl/if.hpp:67:   instantiated from here
/usr/local/include/boost-1_33/boost/archive/detail/iserializer.hpp:544: `sizeof'
   applied to incomplete type `boost::STATIC_ASSERTION_FAILURE<false>'
/usr/local/include/boost-1_33/boost/archive/detail/iserializer.hpp: In static 
   member function `static void boost::archive::detail::load_enum_type<Archive, 
   T>::invoke(Archive&, T&) [with Archive = boost::archive::xml_wiarchive, T = 
   const MarkId]':
/usr/local/include/boost-1_33/boost/archive/detail/iserializer.hpp:559:   instantiated from `void boost::archive::load(Archive&, T&) [with Archive = boost::archive::xml_wiarchive, T = const MarkId]'
/usr/local/include/boost-1_33/boost/archive/basic_xml_iarchive.hpp:80:   instantiated from `void boost::archive::basic_xml_iarchive<Archive>::load_override(const boost::serialization::nvp<T>&, int) [with T = const MarkId, Archive = boost::archive::xml_wiarchive]'
/usr/local/include/boost-1_33/boost/archive/xml_wiarchive.hpp:78:   instantiated from `void boost::archive::xml_wiarchive_impl<Archive>::load_override(T&, int) [with T = const boost::serialization::nvp<const MarkId>, Archive = boost::archive::xml_wiarchive]'
/usr/local/include/boost-1_33/boost/archive/detail/interface_iarchive.hpp:84:   instantiated from `Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = const boost::serialization::nvp<const MarkId>, Archive = boost::archive::xml_wiarchive]'
/usr/local/include/boost-1_33/boost/archive/detail/interface_iarchive.hpp:91:   instantiated from `Archive& boost::archive::detail::interface_iarchive<Archive>::operator&(T&) [with T = const boost::serialization::nvp<const MarkId>, Archive = boost::archive::xml_wiarchive]'
/usr/local/include/boost-1_33/boost/serialization/utility.hpp:43:   instantiated from `void boost::serialization::serialize(Archive&, std::pair<F, S>&, unsigned int) [with Archive = boost::archive::xml_wiarchive, F = const MarkId, S = Mark]'
/usr/local/include/boost-1_33/boost/serialization/serialization.hpp:140:   instantiated from `void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::archive::xml_wiarchive, T = std::pair<const MarkId, Mark>]'
/usr/local/include/boost-1_33/boost/archive/detail/iserializer.hpp:158:   instantiated from `void boost::archive::detail::iserializer<Archive, T>::load_object_data(boost::archive::detail::basic_iarchive&, void*, unsigned int) const [with Archive = boost::archive::xml_wiarchive, T = std::pair<const MarkId, Mark>]'
/usr/local/include/boost-1_33/boost/mpl/if.hpp:67:   instantiated from here
/usr/local/include/boost-1_33/boost/archive/detail/iserializer.hpp:491: assignment
    of read-only reference `t'