Trait rayon::iter::plumbing::UnindexedProducer   
source · pub trait UnindexedProducer: Send + Sized {
    type Item;
    // Required methods
    fn split(self) -> (Self, Option<Self>);
    fn fold_with<F>(self, folder: F) -> F
       where F: Folder<Self::Item>;
}Expand description
A variant on Producer which does not know its exact length or
cannot represent it in a usize. These producers act like
ordinary producers except that they cannot be told to split at a
particular point. Instead, you just ask them to split ‘somewhere’.
(In principle, Producer could extend this trait; however, it
does not because to do so would require producers to carry their
own length with them.)