namespace System.Collections.Generic;
/// Items in order, read and written by their index.
[Intrinsic]
public interface IList<T> : ICollection<T> {
T this[i32 index] { get; set; }
/// Where `item` first is; -1 when it isn't.
readonly i32 IndexOf(T item);
void Insert(i32 index, T item);
void RemoveAt(i32 index);
}