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use core::marker::{PhantomData, Unpin};
use core::pin::Pin;
use futures_core::future::{Future, TryFuture};
use futures_core::task::{LocalWaker, Poll};
use pin_utils::unsafe_pinned;
#[derive(Debug)]
#[must_use = "futures do nothing unless polled"]
pub struct ErrInto<Fut, E> {
future: Fut,
_marker: PhantomData<E>,
}
impl<Fut: Unpin, E> Unpin for ErrInto<Fut, E> {}
impl<Fut, E> ErrInto<Fut, E> {
unsafe_pinned!(future: Fut);
pub(super) fn new(future: Fut) -> ErrInto<Fut, E> {
ErrInto {
future,
_marker: PhantomData,
}
}
}
impl<Fut, E> Future for ErrInto<Fut, E>
where Fut: TryFuture,
Fut::Error: Into<E>,
{
type Output = Result<Fut::Ok, E>;
fn poll(
mut self: Pin<&mut Self>,
lw: &LocalWaker,
) -> Poll<Self::Output> {
self.future().try_poll(lw)
.map(|res| res.map_err(Into::into))
}
}