Function wrapped 

pub fn wrapped<T>(signed_range: impl RangeBounds<T>) -> impl SignedRange
where
    T: Copy + Into<i64>,

Accepts negative bounds, interpreted relative to the end of the collection.

Examples

wrapped(1..-2); // from 1 to len-2
wrapped(..-2);  // from 0 to len-2
wrapped(-3..);  // from len-3 to end
wrapped(-4..3); // from len-4 to 3