Finding the iterated type

Let's say I want to turn this:

Code:

void calculate_randomness (int * begin, int * end) {
   int * manipulator_array = new int[end - begin];
   // mathematical analysis
}

Into something this:

Code:

template <typename RandIter>
void calculate_randomness (RandIter begin, RandIter end) {
   RandIter::type * manipulator_array = new RandIter::type[end - begin];
   // mathematical analysis
}

RandIter::type is a field I made up just for illustration purposes, but I would like to find its equivalent. If I am given a RandIter, how do I construct an object of type (*RandIter)?

You'll need something like this:

Code:

typename std::iterator_traits<RandIter>::value_type value = *first;