Find_end is misnamed: it is much more similar to search than to find, and a more accurate name would have been search_end.

Like search, find_end attempts to find a subsequence within the range [first1, last1) that is identical to [first2, last2). The difference is that while search finds the first such subsequence, find_end finds the last such subsequence. Find_end returns an iterator pointing to the beginning of that subsequence; if no such subsequence exists, it returns last1.

The two versions of find_end differ in how they determine whether two elements are the same: the first uses operator==, and the second uses the user-supplied function object comp.

The first version of find_end returns the last iterator i in the range [first1, last1 – (last2 – first2)) such that, for every iterator j in the range [first2, last2), *(i + (j – first2)) == *j. The second version of find_end returns the last iterator i in [first1, last1 – (last2 – first2)) such that, for every iterator j in [first2, last2), binary_pred(*(i + (j – first2)), *j) is true. These conditions simply mean that every element in the subrange beginning with i must be the same as the corresponding element in [first2, last2).