How to retrieve multiple objects values in boost serialization

Question

In below code snippet , I am storing 2 objects in 'filename' file but surprised to see first object value retrieval 2 times during de-serialization. Apart from this i would like to store and retrieve multiple class objects in same file . currently i am able to store objects in file but not able to retrieve.

can anybody through some light on this?

#include <fstream>
#include <iostream>
// include headers that implement a archive in simple text format
#include <boost/archive/text_oarchive.hpp>
#include <boost/archive/text_iarchive.hpp>
using namespace std;
/////////////////////////////////////////////////////////////
// object_model
//
// illustrates serialization for a simple type
//
class object_model
{
private:
    friend class boost::serialization::access;
    // When the class Archive corresponds to an output archive, the
    // & operator is defined similar to <<.  Likewise, when the class Archive
    // is a type of input archive the & operator is defined similar to >>.
    template<class Archive>
    void serialize(Archive & ar, const unsigned int version)
    {
        ar & classval;
        ar & property;

    }
    string classval;
    int property;

public:
    object_model(){};
    object_model(string d, int p) :
        classval(d), property(p)
    {}

    string getClassval()
    {
      return classval;
    }

     int getproperty()
     {
         return property;
     }
};

int main() {
    // create and open a character archive for output
    std::ofstream ofs("filename");

    // create class instance
     object_model g("lidar",10);
   {
    // save data to archive

        boost::archive::text_oarchive oa(ofs);
        // write class instance to archive
        oa << g;

    }


   object_model g1("lidar1",20);
      {
       // save data to archive

           boost::archive::text_oarchive oa(ofs);
           // write class instance to archive
           oa << g1;

       }


    // ... some time later restore the class instance to its orginal state
    object_model newg;
    {
        // create and open an archive for input
        std::ifstream ifs("filename");
        boost::archive::text_iarchive ia(ifs);
        // read class state from archive
        ia >> newg;
        cout<<newg.getClassval();
        cout<<newg.getproperty();
        cout<<"done"<<endl;
     }
        // archive and stream closed when destructors are called

    object_model newg1;
        {
            // create and open an archive for input
            std::ifstream ifs("filename");
            boost::archive::text_iarchive ia(ifs);
            // read class state from archive
            ia >> newg1;
            cout<<newg1.getClassval();
            cout<<newg1.getproperty();
            cout<<"done"<<endl;
         }



    return 0;
}

user2997518 user2997518 · Accepted Answer · 2017-05-01T15:59:45

while saving data to archive object you need to redirect both the object altogether .it works perfectly fine for me.

object_model g("lidar",10); object_model g1("lidar1",20);

{ // save data to archive

    boost::archive::text_oarchive oa(ofs);
    // write class instance to archive
    oa << g<<g1;

}

// ... some time later restore the class instance to its orginal state

  object_model newg;
    object_model newg1;

    {
        // create and open an archive for input
        std::ifstream ifs("filename");
        boost::archive::text_iarchive ia(ifs);
        // read class state from archive
        ia >> newg>>newg1;
        cout<<newg.getClassval();
        cout<<newg.getproperty();
        cout<<newg1.getClassval();
        cout<<newg1.getproperty();
        cout<<"done"<<endl;
     }

How to retrieve multiple objects values in boost serialization

1 Answers