Basic non working MPI program

main.cpp

#include <mpi.h>
#include <iostream>

int main(int argc, char ** argv)
{

        MPI_Init(&argc, &argv);
        MPI::COMM_WORLD.Set_errhandler ( MPI::ERRORS_THROW_EXCEPTIONS );

        try{
                MPI_Init(&argc, &argv);
        } catch(MPI::Exception e){}

        MPI_Finalize();

        return 0;
}

working.cpp

#include <mpi.h>
#include <iostream>
#include <cassert>
int main(int argc, char ** argv)
{

        MPI_Init(&argc, &argv);
//      MPI_Errhandler_set(MPI_COMM_WORLD, MPI_ERRORS_RETURN);
//      MPI::COMM_WORLD.Set_errhandler ( MPI::RETURN_ERRORS );
//      MPI_Comm_set_errhandler (MPI_COMM_WORLD, MPI_ERRORS_RETURN);
//      assert(MPI_COMM_WORLD == MPI_COMM_NULL);

        int is_initialized = -1;
        MPI_Initialized(&is_initialized);
        if(!is_initialized)
        {
                MPI_Init(&argc, &argv);
        }
        else
        {
                std::cout << "MPI environment is already initialized" << std::endl;
        }

        MPI_Finalize();

        return 0;
}