From f2e1357654c8a18f72e62e0efee266324020666b Mon Sep 17 00:00:00 2001
From: "Felix S. Klock II" <pnkfelix@pnkfx.org>
Date: Wed, 15 Jan 2020 23:40:33 -0500
Subject: [PATCH] Commenting out unsound specialiation.

If perf results indicate that we need this, then we should try to
emulate it via a series of implementations on concrete types.
---
 src/libcore/ops/range.rs | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/libcore/ops/range.rs b/src/libcore/ops/range.rs
index d38b35165695c..93904a4f7e407 100644
--- a/src/libcore/ops/range.rs
+++ b/src/libcore/ops/range.rs
@@ -360,12 +360,15 @@ impl<T> RangeInclusiveEquality for T {
     }
 }
 
-impl<T: PartialOrd> RangeInclusiveEquality for T {
-    #[inline]
-    fn canonicalized_is_empty(range: &RangeInclusive<Self>) -> bool {
-        range.is_empty()
-    }
-}
+// rust-lang/rust#67194: We cannot use this specialized implementation
+// soundly in Rust today.
+//
+// impl<T: PartialOrd> RangeInclusiveEquality for T {
+//     #[inline]
+//     fn canonicalized_is_empty(range: &RangeInclusive<Self>) -> bool {
+//         range.is_empty()
+//     }
+// }
 
 #[stable(feature = "inclusive_range", since = "1.26.0")]
 impl<Idx: PartialEq> PartialEq for RangeInclusive<Idx> {