Updated SerializedDictionary to implement IReadOnlyDictionary.

Author: snarlynarwhal

Assets/Editor Toolbox/Runtime/Serialization/SerializedDictionary.cs

@@ -10,7 +10,7 @@ namespace UnityEngine
     /// Highly suggested to cast it to a <see cref="Dictionary{TKey, TValue}"/> when used in runtime.
     /// </summary>
     [Serializable]
-    public sealed class SerializedDictionary<TK, TV> : IDictionary<TK, TV>, ISerializationCallbackReceiver
+    public sealed class SerializedDictionary<TK, TV> : IDictionary<TK, TV>, IReadOnlyDictionary<TK, TV>, ISerializationCallbackReceiver
     {
         [Serializable]
         private struct KeyValuePair
@@ -224,6 +224,10 @@ public TV this[TK key]
 
         public bool IsReadOnly => false;
 
+        IEnumerable<TK> IReadOnlyDictionary<TK, TV>.Keys => Keys;
+
+        IEnumerable<TV> IReadOnlyDictionary<TK, TV>.Values => Values;
+
         public static implicit operator Dictionary<TK, TV>(SerializedDictionary<TK, TV> serializedDictionary)
         {
             return serializedDictionary.dictionary;
@@ -235,4 +239,4 @@ public static implicit operator SerializedDictionary<TK, TV>(Dictionary<TK, TV>
         }
     }
 }
-#endif
+#endif