usesuper::Encoding;/// The [CESU-8](https://en.wikipedia.org/wiki/CESU-8) encoding
#[derive(Debug, Default, Hash)]pubstructCesu8;implEncoding forCesu8{fnlength(s:&str)->usize{letmut extra =0;for c in s.chars(){if c >'\u{FFFF}'{
extra +=2;// each 4-byte UTF-8 sequence (BMP > U+FFFF) becomes 6 bytes in CESU-8 (2 extra bytes per character).
}}
s.len()+ extra
}}