Add a comment with implementation notes.
diff --git a/Modules/collectionsmodule.c b/Modules/collectionsmodule.c
index 4026ea5..da276ce 100644
--- a/Modules/collectionsmodule.c
+++ b/Modules/collectionsmodule.c
@@ -359,6 +359,13 @@
return item;
}
+/* delitem() implemented in terms of rotate for simplicity and reasonable
+ performance near the end points. If for some reason this method becomes
+ popular, it is not hard to re-implement this using direct data movement
+ (similar to code in list slice assignment) and achieve a two or threefold
+ performance boost.
+*/
+
static int
deque_del_item(dequeobject *deque, int i)
{