From df01b3a67b33ef0ff7ab1f27f41056093f5b2574 Mon Sep 17 00:00:00 2001
From: r00ster <r00ster91@protonmail.com>
Date: Sun, 18 Apr 2021 15:51:16 +0200
Subject: [PATCH 1/2] Document that `index` and `index_mut` can panic

---
 library/core/src/ops/index.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/library/core/src/ops/index.rs b/library/core/src/ops/index.rs
index a8dea4e9b4ea8..515ccd6aa2389 100644
--- a/library/core/src/ops/index.rs
+++ b/library/core/src/ops/index.rs
@@ -61,6 +61,10 @@ pub trait Index<Idx: ?Sized> {
     type Output: ?Sized;
 
     /// Performs the indexing (`container[index]`) operation.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the index is out of bounds.
     #[stable(feature = "rust1", since = "1.0.0")]
     #[track_caller]
     fn index(&self, index: Idx) -> &Self::Output;
@@ -161,6 +165,10 @@ see chapter in The Book <https://doc.rust-lang.org/book/ch08-02-strings.html#ind
 #[doc(alias = "[]")]
 pub trait IndexMut<Idx: ?Sized>: Index<Idx> {
     /// Performs the mutable indexing (`container[index]`) operation.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the index is out of bounds.
     #[stable(feature = "rust1", since = "1.0.0")]
     #[track_caller]
     fn index_mut(&mut self, index: Idx) -> &mut Self::Output;

From c86ffe9e8910cb1bac1737878a524e146b54375e Mon Sep 17 00:00:00 2001
From: r00ster <r00ster91@protonmail.com>
Date: Sun, 18 Apr 2021 18:16:10 +0200
Subject: [PATCH 2/2] Say that it "may panic"

---
 library/core/src/ops/index.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/library/core/src/ops/index.rs b/library/core/src/ops/index.rs
index 515ccd6aa2389..964378cc9c3c6 100644
--- a/library/core/src/ops/index.rs
+++ b/library/core/src/ops/index.rs
@@ -64,7 +64,7 @@ pub trait Index<Idx: ?Sized> {
     ///
     /// # Panics
     ///
-    /// Panics if the index is out of bounds.
+    /// May panic if the index is out of bounds.
     #[stable(feature = "rust1", since = "1.0.0")]
     #[track_caller]
     fn index(&self, index: Idx) -> &Self::Output;
@@ -168,7 +168,7 @@ pub trait IndexMut<Idx: ?Sized>: Index<Idx> {
     ///
     /// # Panics
     ///
-    /// Panics if the index is out of bounds.
+    /// May panic if the index is out of bounds.
     #[stable(feature = "rust1", since = "1.0.0")]
     #[track_caller]
     fn index_mut(&mut self, index: Idx) -> &mut Self::Output;