(as a maybe unneeded clarification, my previous comment agrees with you) I agree that something like unicode-segmentation should not be in the bundled standard

(as a maybe unneeded clarification, my previous comment agrees with you) I agree that something like unicode-segmentation should not be in the bundled standard library. specifically because the std should be forward compatible. In my opinion it is why foundational libraries should strive to be on Rust 2015 edition rather than the latest.