// CS1061: Type `A' does not contain a definition for `Foo' and no extension method `Foo' of type `A' could be found. Are you missing an assembly reference? // Line: 17 using System; using System.Runtime.CompilerServices; class A { [IndexerName ("Foo")] public int this [int index] { get { return index; } set { ; } } static void Test (A a, int value) { a.Foo = value; } public static void Main () { Test (new A (), 9); } }