// CS1640: foreach statement cannot operate on variables of type `T' because it contains multiple implementation of `System.Collections.Generic.IEnumerable<T>'. Try casting to a specific implementation // Line: 11 using System.Collections.Generic; public class C { public static void Test<T>(T t) where T: IEnumerable<string>, IEnumerable<int> { foreach (int i in t) { } } }