C++ list<list<int> >类型的对象遍历

void listSort(list<list<int> >* initList)
{
    list<list<int> >::iterator itera;
    for(itera = (*initList).begin(); itera!=(*initList).end(); itera ++){
        list<int> ls = *itera;
        for(list<int>::iterator it= ls.begin(); it!=ls.end(); it ++){
            cout << *it << endl;
        }
    }
}
int main()
{

    list<int> ls1;
    ls1.push_front();
    ls1.push_front();
    list<int> ls2;
    ls2.push_front();
    ls2.push_front();
    list<list<int> > lstotal;
    lstotal.push_front(ls1);
    lstotal.push_front(ls2);
    listSort(&lstotal);
    return ;
}