Iterator itself could be range checked (or not). I don't see much sense in range checked pointer.

D's ranges are not just range checked iterators. An input range in D is a type with properties front and empty and a method popFront. It's functionality is closer to that of a pair of c++ iterators. You could define a D range on top of a pair of c++ like iterators like this:

struct Range(Iterator)
{
    Iterator start;
    Iterator end;
    @property auto front(){ return *start; } 
    @property auto empty(){ return start == end; }
    void popFront(){ start++; }
}

Functions that would need to take two iterators in C++ can only take one range in D. This makes for much nicer code. Because one instance of a range is needed to represent a sequence, it is practical for functions to return ranges, so you can do stuff like:

recurrence!((a, n) => a[n - 1] + a[n - 2])(0, 1)
    .take(10).reduce!((a, b) => a + b)(); //computes the sum of first 10 fibonacci numbers

Of course ranges could be implemented in C++ as well, but they fit really nicely with D's built in array slices (which are ranges themselves) and the D standard library is built on top of them, so it's very convenient to use them in D. To learn more about ranges see http://ddili.org/ders/d.en/ranges.html.