IList<T> covariance wrapper

gistfile1.cs

    public class ListWrapper<TSource, TDest> : IList<TDest>
        where TDest : class
        where TSource : TDest
    {
        private readonly IList<TSource> list;

        public ListWrapper(IList<TSource> list)
        {
            this.list = list;
        }
        public int IndexOf(TDest item)
        {
            return list.IndexOf((TSource)item);
        }

        public void Insert(int index, TDest item)
        {
            list.Insert(index, (TSource)item);
        }

        public void RemoveAt(int index)
        {
            list.RemoveAt(index);
        }

        public TDest this[int index]
        {
            get { return list[index]; }
            set { list[index] = (TSource)value; }
        }

        public void Add(TDest item)
        {
            list.Add((TSource)item);
        }

        public void Clear()
        {
            list.Clear();
        }

        public bool Contains(TDest item)
        {
            return list.Contains((TSource)item);
        }

        public void CopyTo(TDest[] array, int arrayIndex)
        {
            list.Cast<TDest>().ToList().CopyTo(array, arrayIndex);
        }

        public int Count
        {
            get { return list.Count; }
        }

        public bool IsReadOnly
        {
            get { return list.IsReadOnly; }
        }

        public bool Remove(TDest item)
        {
            return list.Remove((TSource)item);
        }

        public IEnumerator<TDest> GetEnumerator()
        {
            return list.Cast<TDest>().GetEnumerator();
        }

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }