fn split_once(s: &'_ str, delimiter: char) -> Option<(&'_ str, &'_ str)> {
    let start = s.find(delimiter)?;
    let end = start + delimiter.len_utf8();
    Some((&s[..start], &s[end..]))
}
// stolen from the stdlib and modified (to work on stable)
stolen from the stdlib and modified (to work on stable)
stolen from the stdlib and modified ( to work on stable )
fn split_once(s: &'_ str, delimiter: char) -> Option<(&'_ str, &'_ str)> {
    let start = s.find(delimiter)?;
    let end = start + delimiter.len_utf8();
    Some((&s[..start], &s[end..]))
}
fn split_once ( s : & ' _ str , delimiter : char ) -> Option < ( & ' _ str , & ' _ str ) > { let start = s . find ( delimiter ) ? ; let end = start + delimiter . len_utf8 ( ) ; Some ( ( & s [ .. start ] , & s [ end .. ] ) ) }
stolen from the stdlib and modified (to work on stable)
stolen from the stdlib and modified ( to work on stable )
s
&'_ str
delimiter
char
s
&'_ str
delimiter
char