Function itertools::interleave 
source · pub fn interleave<I, J>(
    i: I,
    j: J
) -> Interleave<<I as IntoIterator>::IntoIter, <J as IntoIterator>::IntoIter> ⓘwhere
    I: IntoIterator,
    J: IntoIterator<Item = I::Item>,Expand description
Create an iterator that interleaves elements in i and j.
IntoIterator enabled version of i.interleave(j).
use itertools::interleave;
for elt in interleave(&[1, 2, 3], &[2, 3, 4]) {
    /* loop body */
}