// CS0612: `E.GetEnumerator()' is obsolete // Line: 22 // Compiler options: -warnaserror using System.Collections; using System; class E : IEnumerable { [Obsolete] public IEnumerator GetEnumerator () { throw new System.NotImplementedException (); } } class C { public static void Main () { var e = new E (); foreach (var entry in e) { } } }