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//@ run-pass
//@ revisions: default feature
#![cfg_attr(feature, feature(arbitrary_self_types))]
use std::pin::Pin;
use std::ops::DerefMut;
use std::marker::Unpin;
struct TryChunks;
impl TryChunks {
#[allow(dead_code)]
fn take(self: std::pin::Pin<&mut Self>) -> usize {
1
}
}
#[allow(dead_code)]
trait Stream {
fn poll_next(self: std::pin::Pin<&mut Self>);
}
#[allow(dead_code)]
trait StreamExt: Stream {
#[allow(dead_code)]
fn take(self) -> usize where Self: Sized
{
2
}
}
impl<T: ?Sized> StreamExt for T where T: Stream {}
impl Stream for TryChunks {
fn poll_next(self: std::pin::Pin<&mut Self>) {
assert_eq!(self.take(), 1);
}
}
#[allow(dead_code)]
impl<S: ?Sized + Stream + Unpin> Stream for &mut S {
#[allow(dead_code)]
fn poll_next(mut self: Pin<&mut Self>) {
S::poll_next(Pin::new(&mut **self))
}
}
#[allow(dead_code)]
impl<P> Stream for Pin<P>
where
P: DerefMut + Unpin,
P::Target: Stream,
{
#[allow(dead_code)]
fn poll_next(self: Pin<&mut Self>) {
self.get_mut().as_mut().poll_next()
}
}
fn main() {
let mut item = Box::pin(TryChunks);
item.as_mut().poll_next();
}
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