simple iterator for container

iterator.cpp

#include <iostream>
#include <fstream>

using namespace std;

template <typename T>
class Vector {
private:
  T* data;
  int _size;
public:
   class iterator {
  private:
    T* ptr;
  public:
    iterator(T* aPtr): ptr(aPtr) {}
    iterator operator++() { 
      ptr++;
      return *this;
    }
    iterator operator--() {
      ptr--;
      return *this;
    }
    T& operator*() {
      return *this->ptr;
    }
    T* operator->() {
      return this->ptr;
    }
    bool operator==(const iterator& r) {
      return this->ptr == r.ptr;
    }
    bool operator!=(const iterator& r) {
      return this->ptr != r.ptr;
    }
  };

  Vector(int aSize): _size(aSize) {
    this->data = new T[this->_size];
  }

  ~Vector() {
    delete[] this->data;
  }

  int size() {
    return this->_size;
  }

  T& operator[](int index) {
    return this->data[index];
  }

  iterator begin() {
    return iterator(this->data);
  }

  iterator end() {
    return iterator(this->data + this->_size);
  }
};

int main() {
  Vector<int> vectorInt(3);
  vectorInt[0] = 1;
  vectorInt[1] = 2;
  vectorInt[2] = 3;

  for (Vector<int>::iterator i = vectorInt.begin(); i != vectorInt.end(); ++i) {
    cout << *i << endl;
  }


  Vector<double> vectorDouble(3);
  vectorDouble[0] = 1.1;
  vectorDouble[1] = 2.2;
  vectorDouble[2] = 3.3;

  for (Vector<double>::iterator i = vectorDouble.begin(); i != vectorDouble.end(); ++i) {
    cout << *i << endl;
  }

  return 0;
}