custom iterator for a collection interface - c++

Question

I have an interface ICollection implementing a collection ArdalanCollection like this:
template <typename T>
class ICollection
{
public:
virtual void add(T*) = 0;
virtual T* get(int) = 0;
virtual int count() = 0;
};
template <typename T>
class ArdalanCollection :public ICollection<T>
{
public:
ArdalanCollection() {
index = 0;
};
virtual void add(T* obj) {
encapsolateImplementation.insert(make_pair(index++, obj));
};
virtual T* get(int index) {
return encapsolateImplementation[index];
};
virtual int count() {
return encapsolateImplementation.size();
};
private:
int index;
unordered_map < int, T* > encapsolateImplementation;
};
what I want is to have a generic iterator in ICollection interface which can loop all over the internal container elements(I haven't decided to choose unordered_map as my internal container I might change it to boost or something else). I want to use it in this way:
Node *node1 = new Node(1, 0, 0, 0);
Node *node2 = new Node(1, 0, 0, 0);
ICollection<Node> *nodes = new ArdalanCollection<Node>();
nodes->add(node1);
nodes->add(node2);
for (it=nodes->iterator.begin(); it < nodes->iterator.end(); it++) {
}

Answer 1

First your for loop idiom is not correct. It should rather look like
for(auto it = nodes->begin(); it != nodes->end(); it++)
then something along:
template <typename T, typename MyMap>
class ICollection
{
public:
typedef typename MyMap<int, T *>::iterator iterator;
virtual void add(T*) = 0;
virtual T* get(int) = 0;
virtual int count() = 0;
};
should be fine.