ArraySegment<T>

sample.cs

class Program
{
    static void Main(string[] args)
    {

        var foo = new[] { 0, 1, 2, 3, 4 }.ToArray();
        var bar = new ArraySegment<int>(foo, 0, 2);
        foo[0] = -1;
        Console.WriteLine(ReferenceEquals(foo, bar.Array)); // True
        Console.WriteLine(bar.ElementAt(0)); // -1
    }
}