From d2c069de1e85cf6d236d040a5be4021092bfdb57 Mon Sep 17 00:00:00 2001
From: Vlad-Shcherbina <vlad.shcherbina@gmail.com>
Date: Wed, 17 Jan 2018 21:40:47 +0300
Subject: [PATCH] Document map_clone known problems #498

(cherry picked from commit ada0d2c54831a904a53ff4106e0ebb6a0f06a687)
---
 clippy_lints/src/map_clone.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/clippy_lints/src/map_clone.rs b/clippy_lints/src/map_clone.rs
index 8ca1fbb2759..d45fcc7e860 100644
--- a/clippy_lints/src/map_clone.rs
+++ b/clippy_lints/src/map_clone.rs
@@ -27,7 +27,9 @@ pub struct Pass;
 ///
 /// **Why is this bad?** Readability, this can be written more concisely
 ///
-/// **Known problems:** None.
+/// **Known problems:** Sometimes `.cloned()` requires stricter trait
+/// bound than `.map(|e| e.clone())` (which works because of the coercion).
+/// See [#498](https://github.com/rust-lang-nursery/rust-clippy/issues/498).
 ///
 /// **Example:**
 ///