Function split_str_with_ranges 

pub fn split_str_with_ranges<'s>(
    s: &'s str,
    pat: &dyn Fn(char) -> bool,
) -> Vec<(Range<usize>, &'s str)>

Similar to str::split, but also provides byte-offset ranges of the results. Unlike str::split, this is not generic on pattern types and does not return an Iterator.