Rollup merge of #60187 - tmandry:generator-optimization, r=eddyb

[rust.git] / src / librustc_data_structures / indexed_vec.rs

diff --git a/src/librustc_data_structures/indexed_vec.rs b/src/librustc_data_structures/indexed_vec.rs
index 359b89f683dc4ea7cc9f4da87e0579aa0862f2c5..c7f6e54c3d56b1dd713af054614859256a7721bb 100644 (file)
--- a/src/librustc_data_structures/indexed_vec.rs
+++ b/src/librustc_data_structures/indexed_vec.rs
@@ -212,6 +212,11 @@ fn sub_one(&self) -> Self {
             fn add_usize(&self, u: usize) -> Option<Self> {
                 Idx::index(*self).checked_add(u).map(Self::new)
             }
+
+            #[inline]
+            fn sub_usize(&self, u: usize) -> Option<Self> {
+                Idx::index(*self).checked_sub(u).map(Self::new)
+            }
         }
 
         impl From<$type> for u32 {