Wrap state enum in public struct
@@ -5,9 +5,13 @@ use crate::future::Future;
use crate::future::IntoFuture;
use crate::task::{Context, Poll};
-#[doc(hidden)]
#[derive(Debug)]
-pub enum FlattenFuture<Fut1, Fut2> {
+pub struct FlattenFuture<Fut1, Fut2> {
+ state: State<Fut1, Fut2>,
+}
+
+#[derive(Debug)]
+enum State<Fut1, Fut2> {
First(Fut1),
Second(Fut2),
Empty,
@@ -15,7 +19,9 @@ pub enum FlattenFuture<Fut1, Fut2> {
impl<Fut1, Fut2> FlattenFuture<Fut1, Fut2> {
pub fn new(future: Fut1) -> FlattenFuture<Fut1, Fut2> {
- FlattenFuture::First(future)
+ FlattenFuture {
+ state: State::First(future),
+ }
}
}
@@ -27,19 +33,19 @@ where
type Output = <Fut1::Output as IntoFuture>::Output;
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
- let this = unsafe { self.get_unchecked_mut() };
+ let Self { state } = unsafe { self.get_unchecked_mut() };
loop {
- match this {
- FlattenFuture::First(fut1) => {
+ match state {
+ State::First(fut1) => {
let fut2 = ready!(unsafe { Pin::new_unchecked(fut1) }.poll(cx)).into_future();
- *this = FlattenFuture::Second(fut2);
+ *state = State::Second(fut2);
}
- FlattenFuture::Second(fut2) => {
+ State::Second(fut2) => {
let v = ready!(unsafe { Pin::new_unchecked(fut2) }.poll(cx));
- *this = FlattenFuture::Empty;
+ *state = State::Empty;
return Poll::Ready(v);
}
- FlattenFuture::Empty => unreachable!(),
+ State::Empty => panic!("polled a completed future"),
}
}
}
