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use core::marker::PhantomData;
use core::pin::Pin;
use core::task::{Context, Poll};
use crate::stream::{DoubleEndedStream, ExactSizeStream, FusedStream, Stream};
#[derive(Debug)]
pub struct Pending<T> {
_marker: PhantomData<T>,
}
pub fn pending<T>() -> Pending<T> {
Pending {
_marker: PhantomData,
}
}
impl<T> Stream for Pending<T> {
type Item = T;
fn poll_next(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Option<T>> {
Poll::Pending
}
}
impl<T> DoubleEndedStream for Pending<T> {
fn poll_next_back(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Option<T>> {
Poll::Pending
}
}
impl<T> FusedStream for Pending<T> {}
impl<T> ExactSizeStream for Pending<T> {
fn len(&self) -> usize {
0
}
}