From a196641dc7518cf9eb028efbf73c3d0ba4f78900 Mon Sep 17 00:00:00 2001
From: Yoshua Wuyts <yoshuawuyts@gmail.com>
Date: Wed, 16 Sep 2020 12:43:54 +0200
Subject: [PATCH] Rename core::future::poll_fn to core::future::from_fn

---
 .../src/future/{poll_fn.rs => from_fn.rs}     | 37 +++++++++----------
 library/core/src/future/mod.rs                |  6 +--
 library/std/src/future.rs                     |  4 ++
 library/std/src/lib.rs                        |  1 +
 4 files changed, 26 insertions(+), 22 deletions(-)
 rename library/core/src/future/{poll_fn.rs => from_fn.rs} (51%)

diff --git a/library/core/src/future/poll_fn.rs b/library/core/src/future/from_fn.rs
similarity index 51%
rename from library/core/src/future/poll_fn.rs
rename to library/core/src/future/from_fn.rs
index f302cda09e721..a2b3b3d22bfe7 100644
--- a/library/core/src/future/poll_fn.rs
+++ b/library/core/src/future/from_fn.rs
@@ -10,49 +10,48 @@ use crate::task::{Context, Poll};
 /// # Examples
 ///
 /// ```
-/// #![feature(future_poll_fn)]
+/// #![feature(future_from_fn)]
 /// # async fn run() {
-/// use core::future::poll_fn;
+/// use core::future;
 /// use core::task::{Context, Poll};
 ///
-/// fn read_line(_cx: &mut Context<'_>) -> Poll<String> {
+/// let fut = future::from_fn(|_cx: &mut Context<'_>| -> Poll<String> {
 ///     Poll::Ready("Hello, World!".into())
-/// }
+/// });
 ///
-/// let read_future = poll_fn(read_line);
-/// assert_eq!(read_future.await, "Hello, World!".to_owned());
+/// assert_eq!(fut.await, "Hello, World!".to_owned());
 /// # };
 /// ```
-#[unstable(feature = "future_poll_fn", issue = "72302")]
-pub fn poll_fn<T, F>(f: F) -> PollFn<F>
+#[unstable(feature = "future_from_fn", issue = "72302")]
+pub fn from_fn<T, F>(f: F) -> FromFn<F>
 where
     F: FnMut(&mut Context<'_>) -> Poll<T>,
 {
-    PollFn { f }
+    FromFn { f }
 }
 
 /// A Future that wraps a function returning `Poll`.
 ///
-/// This `struct` is created by [`poll_fn()`]. See its
+/// This `struct` is created by [`from_fn()`]. See its
 /// documentation for more.
 #[must_use = "futures do nothing unless you `.await` or poll them"]
-#[unstable(feature = "future_poll_fn", issue = "72302")]
-pub struct PollFn<F> {
+#[unstable(feature = "future_from_fn", issue = "72302")]
+pub struct FromFn<F> {
     f: F,
 }
 
-#[unstable(feature = "future_poll_fn", issue = "72302")]
-impl<F> Unpin for PollFn<F> {}
+#[unstable(feature = "future_from_fn", issue = "72302")]
+impl<F> Unpin for FromFn<F> {}
 
-#[unstable(feature = "future_poll_fn", issue = "72302")]
-impl<F> fmt::Debug for PollFn<F> {
+#[unstable(feature = "future_from_fn", issue = "72302")]
+impl<F> fmt::Debug for FromFn<F> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("PollFn").finish()
+        f.debug_struct("FromFn").finish()
     }
 }
 
-#[unstable(feature = "future_poll_fn", issue = "72302")]
-impl<T, F> Future for PollFn<F>
+#[unstable(feature = "future_from_fn", issue = "72302")]
+impl<T, F> Future for FromFn<F>
 where
     F: FnMut(&mut Context<'_>) -> Poll<T>,
 {
diff --git a/library/core/src/future/mod.rs b/library/core/src/future/mod.rs
index fa5655ca35f41..0c318104c0a42 100644
--- a/library/core/src/future/mod.rs
+++ b/library/core/src/future/mod.rs
@@ -9,10 +9,10 @@ use crate::{
     task::{Context, Poll},
 };
 
+mod from_fn;
 mod future;
 mod into_future;
 mod pending;
-mod poll_fn;
 mod ready;
 
 #[stable(feature = "futures_api", since = "1.36.0")]
@@ -26,8 +26,8 @@ pub use pending::{pending, Pending};
 #[stable(feature = "future_readiness_fns", since = "1.48.0")]
 pub use ready::{ready, Ready};
 
-#[unstable(feature = "future_poll_fn", issue = "72302")]
-pub use poll_fn::{poll_fn, PollFn};
+#[unstable(feature = "future_from_fn", issue = "72302")]
+pub use from_fn::{from_fn, FromFn};
 
 /// This type is needed because:
 ///
diff --git a/library/std/src/future.rs b/library/std/src/future.rs
index 9d9c36e9afb0f..d1076b060a0d7 100644
--- a/library/std/src/future.rs
+++ b/library/std/src/future.rs
@@ -12,6 +12,10 @@ pub use core::future::{from_generator, get_context, ResumeTy};
 #[stable(feature = "future_readiness_fns", since = "1.48.0")]
 pub use core::future::{pending, ready, Pending, Ready};
 
+#[doc(inline)]
+#[unstable(feature = "future_from_fn", issue = "72302")]
+pub use core::future::{from_fn, FromFn};
+
 #[doc(inline)]
 #[unstable(feature = "into_future", issue = "67644")]
 pub use core::future::IntoFuture;
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 309657e70424b..abf0afb7f9a57 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -258,6 +258,7 @@
 #![feature(external_doc)]
 #![feature(fn_traits)]
 #![feature(format_args_nl)]
+#![feature(future_from_fn)]
 #![feature(gen_future)]
 #![feature(generator_trait)]
 #![feature(global_asm)]