From ada0d2c54831a904a53ff4106e0ebb6a0f06a687 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

---
 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 e126d5c07d70..8403974629d6 100644
--- a/clippy_lints/src/map_clone.rs
+++ b/clippy_lints/src/map_clone.rs
@@ -10,7 +10,9 @@ use utils::{is_adjusted, iter_input_pats, match_qpath, match_trait_method, match
 /// **Why is this bad?** It makes the code less readable than using the
 /// `.cloned()` adapter.
 ///
-/// **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:**
 /// ```rust