From 6a90eca8fce7edc34b3b11145781fd413c609ce5 Mon Sep 17 00:00:00 2001
From: Manish Goregaokar <manishsmail@gmail.com>
Date: Mon, 26 Jan 2015 20:33:07 +0530
Subject: [PATCH] Add on_unimplemented note to Index

---
 src/libcore/ops.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/libcore/ops.rs b/src/libcore/ops.rs
index 372596cdd44..002c04f852a 100644
--- a/src/libcore/ops.rs
+++ b/src/libcore/ops.rs
@@ -895,6 +895,7 @@ shr_impl_all! { u8 u16 u32 u64 usize i8 i16 i32 i64 isize }
 /// }
 /// ```
 #[lang="index"]
+#[rustc_on_unimplemented = "the type `{Self}` cannot be indexed by `{Index}`"]
 #[stable]
 pub trait Index<Index: ?Sized> {
     type Output: ?Sized;
@@ -933,6 +934,7 @@ pub trait Index<Index: ?Sized> {
 /// }
 /// ```
 #[lang="index_mut"]
+#[rustc_on_unimplemented = "the type `{Self}` cannot be mutably indexed by `{Index}`"]
 #[stable]
 pub trait IndexMut<Index: ?Sized> {
     type Output: ?Sized;