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use futures::channel::mpsc;
use futures::stream::Stream;
#[test]
fn unbounded_size_hint() {
let (tx, mut rx) = mpsc::unbounded::<u32>();
assert_eq!((0, None), rx.size_hint());
tx.unbounded_send(1).unwrap();
assert_eq!((1, None), rx.size_hint());
rx.try_next().unwrap().unwrap();
assert_eq!((0, None), rx.size_hint());
tx.unbounded_send(2).unwrap();
tx.unbounded_send(3).unwrap();
assert_eq!((2, None), rx.size_hint());
drop(tx);
assert_eq!((2, Some(2)), rx.size_hint());
rx.try_next().unwrap().unwrap();
assert_eq!((1, Some(1)), rx.size_hint());
rx.try_next().unwrap().unwrap();
assert_eq!((0, Some(0)), rx.size_hint());
}
#[test]
fn channel_size_hint() {
let (mut tx, mut rx) = mpsc::channel::<u32>(10);
assert_eq!((0, None), rx.size_hint());
tx.try_send(1).unwrap();
assert_eq!((1, None), rx.size_hint());
rx.try_next().unwrap().unwrap();
assert_eq!((0, None), rx.size_hint());
tx.try_send(2).unwrap();
tx.try_send(3).unwrap();
assert_eq!((2, None), rx.size_hint());
drop(tx);
assert_eq!((2, Some(2)), rx.size_hint());
rx.try_next().unwrap().unwrap();
assert_eq!((1, Some(1)), rx.size_hint());
rx.try_next().unwrap().unwrap();
assert_eq!((0, Some(0)), rx.size_hint());
}
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