boost multi_index_container serialization

Question

I am trying to use the boost::multi_index_container with the boost::serialization. However when I use Pointer to objects as elements and a non_unique order, I get a memory access violation loading the serialized container. I find it interesting that the error doesn't occur for unique ordering or using objects instead of pointers as container elements.

Can somebody tell me if there is a problem with my code or if this is a bug in the boost library?

Here is a minimal example that produces the described error:

#include <boost/multi_index_container.hpp>
#include <boost/archive/binary_oarchive.hpp>
#include <boost/archive/binary_iarchive.hpp>
#include <boost/serialization/set.hpp>
#include <boost/lexical_cast.hpp>

#include <boost/multi_index/ordered_index.hpp>
#include <boost/multi_index/member.hpp>

#include <fstream>

using namespace std;
using namespace boost::multi_index;


struct element {

    friend class boost::serialization::access;

    std::string member1;

    element( int num ) { member1 = boost::lexical_cast<string>( num ); }
    element() {}

    template<class Archive>
    void serialize(Archive & ar, const unsigned int version)
    {
        ar & member1;
    }
};

int main( int argc, const char *argv[] )
{

    typedef multi_index_container<element *, indexed_by<ordered_non_unique<member<element, std::string, &element::member1>>>>  TestSet;

    TestSet myset;

    srand( time (NULL ));
    for (int i = 0; i < 20; i++) {
        myset.insert(new element(rand()));  
    }

    // Write set
    ofstream os("test.bin");
    boost::archive::binary_oarchive boa(os);

    boa << myset;
    os.close();

    // Read set
    TestSet newset;
    ifstream is("test.bin");
    boost::archive::binary_iarchive bia(is);

    bia >> newset;

    return 0;
}

Answer 1

ofstream os("test.bin"); should be: ofstream os("test.bin", ios::binary);

Also:

ifstream is("test.bin"); should be: ifstream is("test.bin", ios::binary);