C++ :: Specific Iterator Type - Find Distance By Simple Subtraction

I have a templated container that defines a forward iterator.

Calling std::distance on these iterators will generate code that will count the number of iterations it takes to get from the first parameter to the second, by repetitively incrementing.

Internally, the iterators can easily find the distance by a simple subtraction.

What I want to do is overload std::distance for these iterators so that it will take advantage of the simple calculation rather than repetitive increments.

The simple solution of course would be to make the iterators random access, but this would require that they support functionality that is not 'logical' for the container. Access to the container only makes logical sense when iterating one item at a time in the forward direction.

Code:
#include <iterator>
template <typename T>
class Container {
public:
class iterator : public std::iterator<std::forward_iterator_tag, T> {

[Code] .....