Remove Never type alias

Author: taiki-e

futures-sink/src/lib.rs

@@ -158,10 +158,10 @@ where
 #[cfg(feature = "alloc")]
 mod if_alloc {
     use super::*;
-    use core::convert::Infallible as Never;
+    use core::convert::Infallible;
 
     impl<T> Sink<T> for alloc::vec::Vec<T> {
-        type Error = Never;
+        type Error = Infallible;
 
         fn poll_ready(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
             Poll::Ready(Ok(()))
@@ -183,7 +183,7 @@ mod if_alloc {
     }
 
     impl<T> Sink<T> for alloc::collections::VecDeque<T> {
-        type Error = Never;
+        type Error = Infallible;
 
         fn poll_ready(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
             Poll::Ready(Ok(()))

futures-util/src/future/future/mod.rs

@@ -6,10 +6,10 @@
 #[cfg(feature = "alloc")]
 use alloc::boxed::Box;
 use core::pin::Pin;
+use core::convert::Infallible;
 
 use crate::fns::{inspect_fn, into_fn, ok_fn, InspectFn, IntoFn, OkFn};
 use crate::future::{assert_future, Either};
-use crate::never::Never;
 use crate::stream::assert_stream;
 #[cfg(feature = "alloc")]
 use futures_core::future::{BoxFuture, LocalBoxFuture};
@@ -83,7 +83,7 @@ delegate_all!(
 delegate_all!(
     /// Future for the [`never_error`](super::FutureExt::never_error) combinator.
     NeverError<Fut>(
-        Map<Fut, OkFn<Never>>
+        Map<Fut, OkFn<Infallible>>
     ): Debug + Future + FusedFuture + New[|x: Fut| Map::new(x, ok_fn())]
 );
 
@@ -551,7 +551,7 @@ pub trait FutureExt: Future {
     where
         Self: Sized,
     {
-        assert_future::<Result<Self::Output, Never>, _>(NeverError::new(self))
+        assert_future::<Result<Self::Output, Infallible>, _>(NeverError::new(self))
     }
 
     /// A convenience for calling `Future::poll` on `Unpin` future types.

futures-util/src/lib.rs

@@ -324,8 +324,6 @@ pub use crate::sink::SinkExt;
 
 pub mod task;
 
-pub mod never;
-
 #[cfg(feature = "compat")]
 #[cfg_attr(docsrs, doc(cfg(feature = "compat")))]
 pub mod compat;

futures-util/src/never.rs

@@ -1,5 +1,5 @@
 use super::assert_sink;
-use crate::never::Never;
+use core::convert::Infallible;
 use core::marker::PhantomData;
 use core::pin::Pin;
 use futures_core::task::{Context, Poll};
@@ -24,16 +24,16 @@ pub struct Drain<T> {
 ///
 /// let mut drain = sink::drain();
 /// drain.send(5).await?;
-/// # Ok::<(), futures::never::Never>(()) }).unwrap();
+/// # Ok::<(), std::convert::Infallible>(()) }).unwrap();
 /// ```
 pub fn drain<T>() -> Drain<T> {
-    assert_sink::<T, Never, _>(Drain { marker: PhantomData })
+    assert_sink::<T, Infallible, _>(Drain { marker: PhantomData })
 }
 
 impl<T> Unpin for Drain<T> {}
 
 impl<T> Sink<T> for Drain<T> {
-    type Error = Never;
+    type Error = Infallible;
 
     fn poll_ready(
         self: Pin<&mut Self>,

futures-util/src/sink/drain.rs

@@ -29,12 +29,12 @@ pin_project! {
 ///     async move {
 ///         sum += i;
 ///         eprintln!("{}", i);
-///         Ok::<_, futures::never::Never>(sum)
+///         Ok::<_, std::convert::Infallible>(sum)
 ///     }
 /// });
 /// futures::pin_mut!(unfold);
 /// unfold.send(5).await?;
-/// # Ok::<(), futures::never::Never>(()) }).unwrap();
+/// # Ok::<(), std::convert::Infallible>(()) }).unwrap();
 /// ```
 pub fn unfold<T, F, R, Item, E>(init: T, function: F) -> Unfold<T, F, R>
 where

futures-util/src/sink/unfold.rs

@@ -133,7 +133,7 @@ pub use futures_util::{join, pending, poll, select_biased, try_join}; // Async-a
 
 // Module reexports
 #[doc(inline)]
-pub use futures_util::{future, never, sink, stream, task};
+pub use futures_util::{future, sink, stream, task};
 
 #[cfg(feature = "alloc")]
 #[doc(inline)]

futures/src/lib.rs

@@ -1,3 +1,5 @@
+use std::convert::Infallible;
+
 mod sassert_next {
     use futures::stream::{Stream, StreamExt};
     use futures::task::Poll;
@@ -356,7 +358,6 @@ fn with_flush() {
     use futures::channel::oneshot;
     use futures::executor::block_on;
     use futures::future::{self, FutureExt, TryFutureExt};
-    use futures::never::Never;
     use futures::sink::{Sink, SinkExt};
     use std::mem;
     use std::pin::Pin;
@@ -369,7 +370,7 @@ fn with_flush() {
     let mut sink = Vec::new().with(|elem| {
         mem::replace(&mut block, future::ok(()).boxed())
             .map_ok(move |()| elem + 1)
-            .map_err(|_| -> Never { panic!() })
+            .map_err(|_| -> Infallible { panic!() })
     });
 
     assert_eq!(Pin::new(&mut sink).start_send(0).ok(), Some(()));
@@ -392,10 +393,9 @@ fn with_flush() {
 fn with_as_map() {
     use futures::executor::block_on;
     use futures::future;
-    use futures::never::Never;
     use futures::sink::SinkExt;
 
-    let mut sink = Vec::new().with(|item| future::ok::<i32, Never>(item * 2));
+    let mut sink = Vec::new().with(|item| future::ok::<i32, Infallible>(item * 2));
     block_on(sink.send(0)).unwrap();
     block_on(sink.send(1)).unwrap();
     block_on(sink.send(2)).unwrap();