An Optimization That's Impossible in Rust

Title is sort of clickbaity, as the article is about implementing said "impossible" optimization in Rust. I wasn't sure what a good alternative title would be, though, if this is one of those cases where using an alternative title is acceptable. I'm open to suggestions!

The quoted optimization in the post isn't about German strings though, but the C++ style short string optimization (the post references an article describing the difference). A few of the referenced crates do this optimization so the blog is still right to point out that it's completely possible, I just wish it was clearer what optimization they felt was being claimed to be impossible.

How much time would it take to port RocksDB in Rust hypothetically.