[libcxx-commits] [libcxx] [libc++] Introduce one-sided binary search for lower_bound on non-random iterators, and use that to improve the average complexity of set_intersection. (PR #75230)

[Iuri Chaer via libcxx-commits]

ichaer wrote:

Cool, thanks :). Just for context, this code is actually being used in production out there. I work for Splunk, and we've implemented this outside of the standard library to speed up a component that does a number of set intersections, overlaying containers on top of each other (it's more complex, but that's the relevant part in a nutshell). The huge majority of the sets involved contain a tiny subset of what the target contains, so this makes a huge difference, and we thought we should contribute upstream.

Obviously I won't ask you to take me on my word :). Code is truth, I'll spend a bit of time understanding existing benchmarks in the LLVM repo to include something relevant in the pull request.

https://github.com/llvm/llvm-project/pull/75230