STL Iterator and user-defined class

[johnbach]

Is is possible to make STL-Iterator to work with user defined class ,like the one below?

#include <iostream>
#include <stdexcept>
using namespace std;
template <class T>
class Array
{
   public:
      T& operator[] (unsigned i) throw(out_of_range)
      { return data_[i]; }
   protected:
      T data_[100];
};
int main(void)
{
   Array<int> a;
   a[0] = 42;
   a[1] = 10;
   cout<<a[0]<<endl;
#ifdef TEMP
   //How to make this work
   for ( Array<int>::iterator it=a.begin() ; it != a.end(); it++ )
      cout << " " << *it;
#endif
}

If yes,please explain with example

[jsmith]

In all cases STL "iterators" are types owned by the container. You have to do the same
thing... ie, make your own iterator type for Array<>.

You will need to research what are the requirements for iterators, as there are a number.

In your case, your (forward) iterator type can be simple: a T*.

Start with:

template< typename T >
class Array
{
  public:
      typedef T* iterator;
      typedef const T* const_iterator;
};

To be STL compatible, you will also need a reverse_iterator and const_reverse_iterator, both of which will require classes to implement.

Since your container is pretty much a std::vector<>, I'd look to see what vector<> does and mimic it.