From 4847c097b46265963bbf9cd8006456b3ff31169b Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Mon, 4 Feb 2019 22:41:39 +0900
Subject: [PATCH] Add #[must_use] to core::task::Poll

---
 src/libcore/task/poll.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/libcore/task/poll.rs b/src/libcore/task/poll.rs
index 27b1139e15c..ac656153519 100644
--- a/src/libcore/task/poll.rs
+++ b/src/libcore/task/poll.rs
@@ -7,6 +7,7 @@ use result::Result;
 
 /// Indicates whether a value is available or if the current task has been
 /// scheduled to receive a wakeup instead.
+#[must_use = "this `Poll` may be a `Pending` variant, which should be handled"]
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
 pub enum Poll<T> {
     /// Represents that a value is immediately ready.