pub fn rev<I>(iterable: I) -> Rev<I::IntoIter>where
    I: IntoIterator,
    I::IntoIter: DoubleEndedIterator,Expand description
Iterate iterable in reverse.
IntoIterator enabled version of .rev().
use itertools::rev;
for elt in rev(&[1, 2, 3]) {
    /* loop body */
}