Question

I am trying to implement a generic (template) bidirectional linked list, similar to C#.NET implementation.

I wanted to build a “short cut” method to get at element with a certain index and decided to go with the subscript operator. I did just like in the instructions, and came up with something like this.

template <typename  T>
class List
{
public:
    T& operator[] (int index) 
    { 
        return iterator->GetCurrentValue(); //iterator is of type Iterator<T> and returns T&
    }
};

however when I get to use this in my code:

List<int>* myList = new List<int>();
...
int value=myList[i]; //i is int

I get a compiler error: main.cpp:18: error: cannot convert 'List<int>' to 'int' in initialization on the last line.

I tried it to return value, not reference, but still the same error.

Why is it interpreting int return value as List<int>?

I am using NetBeans with Cygwin gcc-c++.

Answer 1

Why is it interpreting int return value as List<int>?

It’s not. myList is a pointer to a List, it’s not a List itself. You’d need to use (*myList)[i].

It’s quite unlikely that you really need dynamic allocation in this scenario, so my suggestion would be to not use a pointer, and to not use new.