using System;

public interface IRead
    {
        float this[string name] { get; }
    }
 
    public interface IWrite
    {
        float this[string name] { set; }
    }
 
    public class Impl : IRead, IWrite
    {
        public float this[string name]
        {
            get { return 0; }
            set { }
        }
    }
    
public class Test
{
	public static void Main()
	{
	    Impl impl = new Impl();
	    impl["test"] = 42;
	    float x = impl["test"];
	}
}