1 files changed, 35 insertions, 0 deletions
diff --git a/Xamarin.Forms.Core/ReadOnlyCastingList.cs b/Xamarin.Forms.Core/ReadOnlyCastingList.cs
new file mode 100644
index 00000000..a3f880c3
--- /dev/null
+++ b/Xamarin.Forms.Core/ReadOnlyCastingList.cs
@@ -0,0 +1,35 @@
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Xamarin.Forms
+{
+	internal class ReadOnlyCastingList<T, TFrom> : IReadOnlyList<T> where T : class where TFrom : class
+	{
+		readonly IList<TFrom> _list;
+
+		public ReadOnlyCastingList(IList<TFrom> list)
+		{
+			_list = list;
+		}
+
+		IEnumerator IEnumerable.GetEnumerator()
+		{
+			return ((IEnumerable)_list).GetEnumerator();
+		}
+
+		public IEnumerator<T> GetEnumerator()
+		{
+			return new CastingEnumerator<T, TFrom>(_list.GetEnumerator());
+		}
+
+		public int Count
+		{
+			get { return _list.Count; }
+		}
+
+		public T this[int index]
+		{
+			get { return _list[index] as T; }
+		}
+	}
+}
+\ No newline at end of file