The first occurrence of "UB" appeared without being ever introduced as an
abbreviation. It took me some time to get what it means. It was not had, but I
suspect that the space it wins in a manual is not worth its use here, so I
suggest to replace it by the two words.
However, I also suggest introduce this abbreviation explicitly, which will
prepare people who join some unsafe Rust discussion outside of this book.
The first occurrence of "UB" appeared without being ever introduced as an abbreviation. It took me some time to get what it means. It was not had, but I suspect that the space it wins in a manual is not worth its use here, so I suggest to replace it by the two words.
However, I also suggest introduce this abbreviation explicitly, which will prepare people who join some unsafe Rust discussion outside of this book.