Static Indexers?

Question

Why are static indexers disallowed in C#? I see no reason why they should not be allowed and furthermore they could be very useful.

For example:

public static class ConfigurationManager 
{
        public object this[string name]
        {
            get => ConfigurationManager.getProperty(name);
            set => ConfigurationManager.editProperty(name, value);
        }

        /// <summary>
        /// This will write the value to the property. Will overwrite if the property is already there
        /// </summary>
        /// <param name="name">Name of the property</param>
        /// <param name="value">Value to be wrote (calls ToString)</param>
        public static void editProperty(string name, object value) 
        {
            var ds = new DataSet();
            var configFile = new FileStream("./config.xml", FileMode.OpenOrCreate);
            ds.ReadXml(configFile);

            if (ds.Tables["config"] == null)
                ds.Tables.Add("config");

            var config = ds.Tables["config"];

            if (config.Rows[0] == null) 
                config.Rows.Add(config.NewRow());

            if (config.Columns[name] == null) 
                config.Columns.Add(name);

            config.Rows[0][name] = value.ToString();

            ds.WriteXml(configFile);
            configFile.Close();
        }

        public static void addProperty(string name, object value) =>
            ConfigurationManager.editProperty(name, value);

        public static object getProperty(string name) 
        {
            var ds = new DataSet();
            var configFile = new FileStream("./config.xml", FileMode.OpenOrCreate);
            ds.ReadXml(configFile);
            configFile.Close();

            if (ds.Tables["config"] == null) return null;

            var config = ds.Tables["config"];

            if (config.Rows[0] == null) return null;
            if (config.Columns[name] == null) return null;

            return config.Rows[0][name];
        }
    }

The above code would benefit greatly from a static indexer. However it won't compile because static indexers are not allowed. Why is this so?

Answer 1

I believe it was considered not to be terribly useful. I think it's a shame too - an example I tend to use is Encoding, where Encoding.GetEncoding("foo") could be Encoding["Foo"]. I don't think it would come up very often, but aside from anything else it just feels a little inconsistent not to be available.

I would have to check, but I suspect it's available in IL (Intermediate Language) already.