public class LuaTemplateTester 
{
    public class mm<K, V> 
    {
        public K Key;
        public V Value;
        Dictionary<K, V> dic = new Dictionary<K, V>();

        public V this[K key]
        {
            get
            {
                
                Debug.Log($"index function: key={key} key.getType={key.GetType().Name}" +
                    $" Key.equals(key)={Key.Equals(key)} " +
                    $" Key.GetHashCode()={Key.GetHashCode()}  key.GetHashCode()={key.GetHashCode()}" +
                    $" dic.ContainsKey(key)={dic.ContainsKey(key)} ");
                return Value;
            }
        }          

        public mm(K key, V value)
        {
            this.Key = key;
            this.Value = value;
            dic.Add(key, value);
        }
    }

    public static mm<int,int> Int2Int=>
        new mm<int,int>(10,10);

    public static mm<string, string> Str2Str => 
        new mm<string, string>("ab", "cd");

    public static mm<GObject, string> Gobject2Str => 
        new mm<GObject, string>(new GObject() { name = "test" }, "ee");
  
}

local v=nil
print("testing int2int")
local i2i = CS.LuaTemplateTester.Int2Int;
v = i2i[10]
print(i2i.Key .. i2i.Value .. (v and "ok" or "nil"))

print("test obj2string")
local o2s = CS.LuaTemplateTester.Gobject2Str;
v = o2s[o2s.Key]
print(type(o2s.Key) .. o2s.Value .. (v and "ok" or "nil"))

print("testing str2str")
local s2s = CS.LuaTemplateTester.Str2Str;
v = s2s["ab"]
print(s2s.Key .. s2s.Value .. (v and "ok" or "nil"))

LUA: testing int2int
index function: key=10 key.getType=Int32 Key.equals(key)=True  Key.GetHashCode()=10  key.GetHashCode()=10 dic.ContainsKey(key)=True 
LUA: 1010ok
LUA: test obj2string
index function: key=FairyGUI.GObject key.getType=GObject Key.equals(key)=True  Key.GetHashCode()=-1996357632  key.GetHashCode()=-1996357632 dic.ContainsKey(key)=True 
LUA: userdataeeok
LUA: testing str2str //注意这里没有打印index function
LUA: abcdnil