From ce032c39313917d5841a094a35d3c31ed880ba60 Mon Sep 17 00:00:00 2001
From: ghosind <ghosind@gmail.com>
Date: Sun, 4 Jun 2023 22:46:05 +0800
Subject: [PATCH] doc: update readme.

---
 README.md | 4 ++++
 map.go    | 1 +
 2 files changed, 5 insertions(+)

diff --git a/README.md b/README.md
index a89869d..64aa645 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,10 @@ This package provides the following data structure interfaces and implementation
 
     - [`ConcurrentHashSet`](https://pkg.go.dev/github.com/ghosind/collection#ConcurrentHashSet): The thread safe implementation of Set based on Go built-in map structure.
 
+- `Map`: A object that maps keys to values, and it cannot contain duplicate key.
+
+    - [`HashMap`](https://pkg.go.dev/github.com/ghosind/collection#HashMap): The implementation of Map based on Go built-in map structure.
+
 ## Installation
 
 You can install this package by the following command.
diff --git a/map.go b/map.go
index ed3c4f2..a2cf092 100644
--- a/map.go
+++ b/map.go
@@ -1,5 +1,6 @@
 package collection
 
+// Map is a object that maps keys to values, and it cannot contain duplicate key.
 type Map[K comparable, V any] interface {
 	// Clear removes all key-value pairs in this map.
 	Clear()