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One-sided binary search, aka meta binary search, has been in the public domain for decades, and has the general advantage of being constant time in the best case, with the downside of executing at most 2*log(N) comparisons vs classic binary search's exact log(N). There are two scenarios in which it really shines: the first one is when operating over non-random-access iterators, because the classic algorithm requires knowing the container's size upfront, which adds N iterator increments to the complexity. The second one is when traversing the container in order, trying to fast-forward to the next value: in that case the classic algorithm requires at least O(N*log(N)) comparisons and, for non-random-access iterators, O(N^2) iterator increments, whereas the one-sided version will yield O(N) operations on both counts, with a best-case of O(log(N)) comparisons which is very common in practice.