dfir_pipes/pull/
pending.rs

1use core::marker::PhantomData;
2use core::pin::Pin;
3
4use crate::pull::{FusedPull, Pull, PullStep, fuse_self};
5use crate::{No, Yes};
6
7/// A pull that is always pending and never yields items or ends.
8#[must_use = "`Pull`s do nothing unless polled"]
9#[derive(Clone, Debug)]
10pub struct Pending<Item> {
11    _phantom: PhantomData<Item>,
12}
13
14impl<Item> Pending<Item> {
15    pub(crate) const fn new() -> Self {
16        Self {
17            _phantom: PhantomData,
18        }
19    }
20}
21
22impl<Item> Default for Pending<Item> {
23    fn default() -> Self {
24        Self::new()
25    }
26}
27
28impl<Item> Unpin for Pending<Item> {}
29
30impl<Item> Pull for Pending<Item> {
31    type Ctx<'ctx> = ();
32
33    type Item = Item;
34    type Meta = ();
35    type CanPend = Yes;
36    type CanEnd = No;
37
38    fn pull(
39        self: Pin<&mut Self>,
40        _ctx: &mut Self::Ctx<'_>,
41    ) -> PullStep<Self::Item, Self::Meta, Self::CanPend, Self::CanEnd> {
42        PullStep::Pending(Yes)
43    }
44
45    fn size_hint(&self) -> (usize, Option<usize>) {
46        (0, Some(0))
47    }
48
49    fuse_self!();
50}
51
52impl<Item> FusedPull for Pending<Item> {}
dfir_pipes/pull/pending.rs

dfir_pipes/pull/
pending.rs
