I was a little disappointed when this StreamingIterator implementation wouldn't compile. The complaint it had about lifetimes didn't seem to make sense to me, and brought Polonius to mind.
I'm not very familiar with the project, but I tried to run polonius on the the code's facts:
Directory: .\inputs\streaming-iterator.rs\nll-facts\{{impl}}-next\
Time: 0.024s
# errors
# move_errors
# subset_errors
Do I get to be excited?