struct Account {
string holder_name;
string holder_password;
double current_sum;
};

int save_to_file(Account * account);
Account * load_from_file(string holder_name);

int main(){
    Account account = { "BEN", "password", 200.0 };
    save_to_file(&account);
    load_from_file("BEN");
    return 0;
}

int save_to_file(Account * account){
    const char * cstr = account->holder_name.c_str();
    int size = sizeof(struct Account);

    FILE * fp = fopen(cstr, "wb");
    char * c;

    c = (char *) account;

   for(int i=0; i < size; i++)
   {
       putc(*c++, fp);
   }

   return fclose(fp);
}

Account * load_from_file(string holder_name)
{
    FILE * fp;
    char *c;
    int i;
    int size = sizeof(struct Account);
    struct Account * ptr = (struct Account *) malloc(sizeof(struct Account));

    if ((fp = fopen(holder_name.c_str(), "rb")) == NULL)
    {
        perror("Error occured while opening file");
        return NULL;
    }

    c = (char *)ptr;

    while ((i = getc(fp))!=EOF)
    {
        *c = i;
        c++;
    }

    fclose(fp);
    return ptr;
}