how to define iterators for elements of a class

[aseemgoyal]

let's say i have the following code :

// this code is for implementing vector in C++
template <class T>
class  Vector
{
  public:
    Vector();
    ~Vector();

    iterator begin();    // return type is iterator
    iterator end();

  private:
    unsigned int my_size;
    unsigned int my_capacity;
    T * buffer;
};

template<class T>
typename Vector<T>::iterator Vector<T>::begin()   // return_type of begin() of buffer
{
    return buffer;
}

Now, as in typename Vector<T>::iterator Vector<T>::begin(), the return type is an iterator of type Vector<T>::iterator. How should i declare/define iterator in the class Vector<T>?
The class is generic, so how will the iterator be defined?

[LB]

For your particular implementation, you can use plain pointers as iterators instead of defining your own iterator classes. If there is a specific reason to define your own iterator classes, then I can't see it from the code you posted.

[aseemgoyal]

@LB this code is just a small fragment, i want to learn how to define iterators for classes.

[LB]

The <iterator> header is your friend:
http://www.cplusplus.com/reference/iterator/
http://en.cppreference.com/w/cpp/header/iterator

You would derive from std::iterator<> and implement it to your needs - it does most of your work for you.
http://www.cplusplus.com/reference/iterator/iterator/
http://en.cppreference.com/w/cpp/iterator/iterator

[Smac89]

Add this anywhere in your class
If you just want your container to work with range based for loops aka for (T object : vector) then you just need this:
using iterator = T*;

If you want practice writing your own iterator, do what LB has just suggested

[LB]

@Smac89: I suggested that and he specifically requested information for making an iterator class by hand instead.