From 34d55b56bde1269f0a0714d04740a5a478e78170 Mon Sep 17 00:00:00 2001
From: Runxi Yu <me@runxiyu.org>
Date: Sun, 21 Sep 2025 22:11:43 +0800
Subject: [PATCH] Update README to reflect ownership rules

---
 ds/map/README | 5 +++++

diff --git a/ds/map/README b/ds/map/README
index bd63a93daa4f04f6bbe8043cd069f308a4a34bdb..e1ed112f3a3b3fc1d9cbbbc29fdda70c6b48499f 100644
--- a/ds/map/README
+++ b/ds/map/README
@@ -2,3 +2,8 @@ map: general-purpose map data structures
 
 You should create a map with the `new` function in each submodule.
 Then, you may use functions defined in this module to manipulate the map.
+
+Note that maps own keys but not values. Do not change the content of the
+[]u8 keys when it's already handled by the map; they are expected to stay
+consistent and their lifetime is automatically managed along with the map.
+However, you must manage the lifetimes of all *opaque values yourself.

-- 
2.48.1