using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var blahs = new List<BaseBlah>();

        var originalBlah = new Blah("Hello World");

        blahs.Add(originalBlah);

        var coercedBlahs = blahs.Select(blah => blah as Blah).Where(blah => blah != null).ToList();

        foreach(var blah in coercedBlahs) {

            Console.WriteLine(blah.Test);

            Console.WriteLine(blah == originalBlah);

        }

    }

}

​

​

public class Blah: BaseBlah {

    public Blah(string test) {

        Test = test;

    }

    public string Test {get;set;}

}

​

public abstract class BaseBlah {

}