DynQueue - dynamically extendable Rayon parallel iterator

A DynQueue<T> can be iterated with into_par_iter producing (DynQueueHandle, T) elements. With the DynQueueHandle<T> a new T can be inserted in the DynQueue<T>, which is currently iterated over.

use dynqueue::DynQueue;

use rayon::iter::IntoParallelIterator as _;
use rayon::iter::ParallelIterator as _;

fn main() {
    let mut result = DynQueue::new(vec![1, 2, 3])
                         .into_par_iter()
                         .map(|(handle, value)| { if value == 2 { handle.enqueue(4) }; value })
                         .collect::<Vec<_>>();
    result.sort();

    assert_eq!(result, vec![1, 2, 3, 4]);
}