The second call uses reverse iterators to find the last element that has a value equal to one element in
searchcoll. To print the position of the element, base() is called to transform the reverse iterator
into an iterator. Thus, you can process the distance from the beginning. Normally, you would have to
add 1 to the result of distance() because the first element has distance 0 but actually is element 1.
However, because base() moves the position of the value to which it refers, you have the same
effect (see Section 9.4.1, page 452, for the description of base