Load code error

void load_join_date(int * day, int * month, int * year)
{
    stringstream holder;
    string mystring;
    ifstream myfile("data.bin");
    if(myfile.is_open())
    {
        getline (myfile, mystring);
        holder << mystring;
        holder >> *day;
        cout << *day << "\n";
        holder.str(std::string());
        getline (myfile, mystring);
        holder << mystring;
        holder >> *month;
        cout << *month << "\n";
        holder.str(std::string());
        getline (myfile, mystring);
        holder << mystring;
        holder >> *year;
        cout << *year << "\n";
        holder.str(std::string());
        myfile.close();
    }
    return;
}