From f8b774fbf1f57e520b58ae3828e4b3a1ddf1d97c Mon Sep 17 00:00:00 2001
From: Manish Goregaokar <manishsmail@gmail.com>
Date: Mon, 7 May 2018 09:27:50 -0700
Subject: Add explanation for #[must_use] on mutex guards

---
 src/libstd/sys_common/remutex.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'src/libstd/sys_common')

diff --git a/src/libstd/sys_common/remutex.rs b/src/libstd/sys_common/remutex.rs
index ce43ec6d9ab..022056f8a8a 100644
--- a/src/libstd/sys_common/remutex.rs
+++ b/src/libstd/sys_common/remutex.rs
@@ -41,7 +41,7 @@ unsafe impl<T: Send> Sync for ReentrantMutex<T> {}
 /// because implementation of the trait would violate Rust’s reference aliasing
 /// rules. Use interior mutability (usually `RefCell`) in order to mutate the
 /// guarded data.
-#[must_use]
+#[must_use = "if unused the ReentrantMutex will immediately unlock"]
 pub struct ReentrantMutexGuard<'a, T: 'a> {
     // funny underscores due to how Deref currently works (it disregards field
     // privacy).
-- 
cgit 1.4.1-3-g733a5