Update #[must_use] message of impl Future types

Refs: rust-lang/rust#60808

Author: taiki-e

futures-channel/src/oneshot.rs

@@ -14,7 +14,7 @@ use crate::lock::Lock;
 /// A future for a value that will be provided by another asynchronous task.
 ///
 /// This is created by the [`channel`] function.
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 #[derive(Debug)]
 pub struct Receiver<T> {
     inner: Arc<Inner<T>>,

futures-test/src/future/assert_unmoved.rs

@@ -10,7 +10,7 @@ use std::thread::panicking;
 /// [`FutureTestExt::assert_unmoved`](super::FutureTestExt::assert_unmoved)
 /// method.
 #[derive(Debug, Clone)]
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct AssertUnmoved<Fut> {
     future: Fut,
     this_ptr: *const AssertUnmoved<Fut>,

futures-test/src/future/pending_once.rs

@@ -10,7 +10,7 @@ use pin_utils::{unsafe_pinned, unsafe_unpinned};
 /// [`FutureTestExt::pending_once`](super::FutureTestExt::pending_once)
 /// method.
 #[derive(Debug, Clone)]
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct PendingOnce<Fut: Future> {
     future: Fut,
     polled_before: bool,

futures-util/src/compat/compat01as03.rs

@@ -17,7 +17,7 @@ pub use io::{AsyncRead01CompatExt, AsyncWrite01CompatExt};
 /// Converts a futures 0.1 Future, Stream, AsyncRead, or AsyncWrite
 /// object to a futures 0.3-compatible version,
 #[derive(Debug)]
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Compat01As03<T> {
     pub(crate) inner: Spawn01<T>,
 }

futures-util/src/compat/compat03as01.rs

@@ -29,7 +29,7 @@ use std::{
 /// [`Stream`](futures::stream::Stream) or
 /// [`Sink`](futures::sink::Sink).
 #[derive(Debug, Clone, Copy)]
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Compat<T> {
     pub(crate) inner: T,
 }

futures-util/src/future/abortable.rs

@@ -8,7 +8,7 @@ use alloc::sync::Arc;
 
 /// A future which can be remotely short-circuited using an `AbortHandle`.
 #[derive(Debug, Clone)]
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Abortable<Fut> {
     future: Fut,
     inner: Arc<AbortInner>,

futures-util/src/future/catch_unwind.rs

@@ -8,7 +8,7 @@ use std::prelude::v1::*;
 
 /// Future for the [`catch_unwind`](super::FutureExt::catch_unwind) method.
 #[derive(Debug)]
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct CatchUnwind<Fut> where Fut: Future {
     future: Fut,
 }

futures-util/src/future/chain.rs

@@ -2,7 +2,7 @@ use core::pin::Pin;
 use futures_core::future::Future;
 use futures_core::task::{Context, Poll};
 
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 #[derive(Debug)]
 pub(crate) enum Chain<Fut1, Fut2, Data> {
     First(Fut1, Option<Data>),

futures-util/src/future/empty.rs

@@ -5,7 +5,7 @@ use futures_core::task::{Context, Poll};
 
 /// Future for the [`empty`] function.
 #[derive(Debug)]
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Empty<T> {
     _data: marker::PhantomData<T>,
 }

futures-util/src/future/flatten.rs

@@ -6,7 +6,7 @@ use futures_core::task::{Context, Poll};
 use pin_utils::unsafe_pinned;
 
 /// Future for the [`flatten`](super::FutureExt::flatten) method.
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Flatten<Fut>
     where Fut: Future,
           Fut::Output: Future,