operator[] does not work

[szidijani]

Hello!

I have a homework for tomorrow, and I simply can't solve it.
I have a list (with template) class, I wrote and it has an operator:

T& operator[](int i)
    {
        ToFirst();
        for(int j=0;j<i;j++)
        {
            StepForward();
        }
        return Act->value;
    }

For using the elements with indexes.
And I've got an another class, which puts the elements of an object(template ) in order.

And when I make a pointer of this classin main, and I try to just write on the console one of the elements...it doesn't work:

int main()
{
    Lista<int> *tmp;
    int b[]={56,2,87,11,8,34,56,1,9,31,5};
    for(int i=0;i<11;i++)
    {
        tmp->InsertLast(b[i]);
    } <- filling my list

     cout<<tmp[3]; 
}

Could someone help me in this?

[Banfa]

At the point where you say <- filling my list you are not filling your list you are writing to uninitialised data because you never allocate an object for tmp to point to and it is therefore pointing at a random place.

Try

Lista<int> *tmp = new Lista<int>;

[szidijani]

Thanks, I fixed it...but I still have problem with it.
I run it, and it says:

v\Adatszerk\las su_rendezesek\L assu_rendezesek _hallgatoi\main .cpp||In function `int main()':|
v\Adatszerk\las su_rendezesek\L assu_rendezesek _hallgatoi\main .cpp|26|error: no match for 'operator<<' in 'std::cout << *(tmp + 48u)'|

However, I wrote that operator.

[Banfa]

An error message without the line of code is not very useful.