Only rebuild if retain actually changed something

cuviper · cuviper · commit f4948486bab8 · 2020-06-11T10:42:07.000-07:00
diff --git a/src/map_core.rs b/src/map_core.rs
@@ -362,8 +362,10 @@ impl<K, V> IndexMapCore<K, V> {
                 self.entries.swap(i - n_deleted, i);
             }
         }
-        self.entries.truncate(len - n_deleted);
-        self.rebuild_hash_table();
+        if n_deleted > 0 {
+            self.entries.truncate(len - n_deleted);
+            self.rebuild_hash_table();
+        }
     }
 
     pub(crate) fn reverse(&mut self) {

Original file line number	Diff line number	Diff line change
`@@ -362,8 +362,10 @@ impl<K, V> IndexMapCore<K, V> {`
`362`	`362`	`self.entries.swap(i - n_deleted, i);`
`363`	`363`	`}`
`364`	`364`	`}`
`365`		`- self.entries.truncate(len - n_deleted);`
`366`		`- self.rebuild_hash_table();`
	`365`	`+ if n_deleted > 0 {`
	`366`	`+ self.entries.truncate(len - n_deleted);`
	`367`	`+ self.rebuild_hash_table();`
	`368`	`+ }`
`367`	`369`	`}`
`368`	`370`
`369`	`371`	`pub(crate) fn reverse(&mut self) {`