From a4a8c241c7bcce3604a0ce130a65084101d0ab47 Mon Sep 17 00:00:00 2001
From: pierwill <pierwill@users.noreply.github.com>
Date: Tue, 7 Dec 2021 11:03:53 -0600
Subject: [PATCH] Require Ord for rustc_index::SparseBitSet::last_set_in

---
 compiler/rustc_index/src/bit_set.rs | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/compiler/rustc_index/src/bit_set.rs b/compiler/rustc_index/src/bit_set.rs
index e2f2324f4a8..5aa213cb701 100644
--- a/compiler/rustc_index/src/bit_set.rs
+++ b/compiler/rustc_index/src/bit_set.rs
@@ -715,6 +715,10 @@ impl<T: Idx> SparseBitSet<T> {
         self.elems.iter()
     }
 
+    bit_relations_inherent_impls! {}
+}
+
+impl<T: Idx + Ord> SparseBitSet<T> {
     fn last_set_in(&self, range: impl RangeBounds<T>) -> Option<T> {
         let mut last_leq = None;
         for e in self.iter() {
@@ -724,8 +728,6 @@ impl<T: Idx> SparseBitSet<T> {
         }
         last_leq
     }
-
-    bit_relations_inherent_impls! {}
 }
 
 /// A fixed-size bitset type with a hybrid representation: sparse when there
@@ -802,7 +804,10 @@ impl<T: Idx> HybridBitSet<T> {
     /// Returns the previous element present in the bitset from `elem`,
     /// inclusively of elem. That is, will return `Some(elem)` if elem is in the
     /// bitset.
-    pub fn last_set_in(&self, range: impl RangeBounds<T>) -> Option<T> {
+    pub fn last_set_in(&self, range: impl RangeBounds<T>) -> Option<T>
+    where
+        T: Ord,
+    {
         match self {
             HybridBitSet::Sparse(sparse) => sparse.last_set_in(range),
             HybridBitSet::Dense(dense) => dense.last_set_in(range),