From 3e9d1e40cb2a4dc1e1d303e9d9fa382c34106277 Mon Sep 17 00:00:00 2001
From: Scott McMurray <scottmcm@users.noreply.github.com>
Date: Fri, 27 Jan 2023 19:09:52 -0800
Subject: [PATCH] Link to the LLVM issue from a comment on
 `SpecOptionPartialEq`

---
 library/core/src/option.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/library/core/src/option.rs b/library/core/src/option.rs
index 4aeb707fa6788..c43b728022d2f 100644
--- a/library/core/src/option.rs
+++ b/library/core/src/option.rs
@@ -2090,6 +2090,12 @@ impl<T: PartialEq> PartialEq for Option<T> {
     }
 }
 
+/// This specialization trait is a workaround for LLVM not currently (2023-01)
+/// being able to optimize this itself, even though Alive confirms that it would
+/// be legal to do so: </~https://github.com/llvm/llvm-project/issues/52622>
+///
+/// Once that's fixed, `Option` should go back to deriving `PartialEq`, as
+/// it used to do before </~https://github.com/rust-lang/rust/pull/103556>.
 #[unstable(feature = "spec_option_partial_eq", issue = "none", reason = "exposed only for rustc")]
 #[doc(hidden)]
 pub trait SpecOptionPartialEq: Sized {