1 files changed, 6 insertions, 2 deletions
diff --git a/compiler/rustc_data_structures/src/unord.rs b/compiler/rustc_data_structures/src/unord.rs
index 6c8d54146..2b21815b6 100644
--- a/compiler/rustc_data_structures/src/unord.rs
+++ b/compiler/rustc_data_structures/src/unord.rs
@@ -107,6 +107,10 @@ impl<T, I: Iterator<Item = T>> UnordItems<T, I> {
     {
         UnordItems(self.0.flat_map(f))
     }
+
+    pub fn collect<C: From<UnordItems<T, I>>>(self) -> C {
+        self.into()
+    }
 }
 
 impl<T> UnordItems<T, std::iter::Empty<T>> {
@@ -140,12 +144,12 @@ impl<T: Ord, I: Iterator<Item = T>> UnordItems<T, I> {
     }
 
     #[inline]
-    pub fn into_sorted_stable_ord(self, use_stable_sort: bool) -> Vec<T>
+    pub fn into_sorted_stable_ord(self) -> Vec<T>
     where
         T: Ord + StableOrd,
     {
         let mut items: Vec<T> = self.0.collect();
-        if use_stable_sort {
+        if !T::CAN_USE_UNSTABLE_SORT {
             items.sort();
         } else {
             items.sort_unstable()