#nullable enable

​

using System;

public abstract class BaseClass<T>

{

    public abstract void TrySomething(out T? output);

}

​

public class Implementation : BaseClass<int>

{

    public override void TrySomething(out int output)

    {

        output = 42;

        Console.WriteLine("Hello World");

    }

}

​

public class Program

{

    public static void Main()

    {

        BaseClass<int> x = new Implementation();

        int y = 0;

        x.TrySomething(out y);

    }

}