Replace a .truncate(0) call with .clear().

nnethercote · nnethercote · commit 7fe09a6551b7 · 2018-11-25T17:54:06.000+11:00
diff --git a/src/librustc_data_structures/snapshot_map/mod.rs b/src/librustc_data_structures/snapshot_map/mod.rs
@@ -106,7 +106,7 @@ impl<K, V> SnapshotMap<K, V>
         self.assert_open_snapshot(snapshot);
         if snapshot.len == 0 {
             // The root snapshot.
-            self.undo_log.truncate(0);
+            self.undo_log.clear();
         } else {
             self.undo_log[snapshot.len] = UndoLog::CommittedSnapshot;
         }

Original file line number	Diff line number	Diff line change
`@@ -106,7 +106,7 @@ impl<K, V> SnapshotMap<K, V>`
`106`	`106`	`self.assert_open_snapshot(snapshot);`
`107`	`107`	`if snapshot.len == 0 {`
`108`	`108`	`// The root snapshot.`
`109`		`- self.undo_log.truncate(0);`
	`109`	`+ self.undo_log.clear();`
`110`	`110`	`} else {`
`111`	`111`	`self.undo_log[snapshot.len] = UndoLog::CommittedSnapshot;`
`112`	`112`	`}`