It took some coaching to get it to use the terse style I prefer, but here’s what 3.5 came up with in a conversation where I first asked about Rust’s support for regular expressions:

  use regex::Regex;
  
  fn strip_suffix_digits(s: &str) -> &str {
    let re = Regex::new(r"_\d+$").unwrap();
    re.replace(s, "").as_ref()
  }

As someone who does not program in Rust I find that quite readable, though I haven’t run it and can’t comment on how it compares outside of LOC. It does depend on the regex crate though.