Function itertools::kmerge_by

pub fn kmerge_by<I, F>(iterable: I,
                       less_than: F)
                       -> KMergeBy<I::Item::IntoIter, F> where I: IntoIterator,
        I::Item: IntoIterator,
        F: FnMut(&I::Item::Item, &I::Item::Item) -> bool

Create an iterator that merges elements of the contained iterators.

Equivalent to iterable.into_iter().kmerge_by(less_than).