using System;

delegate void D(ref S s);

interface I
{
    void M(D d);
}

struct S : I
{
    public void M(D d)
    {
        d(ref this);
    }
}

static class Program
{
    static void Main()
    {
        I i = new S();
        WeakReference w = new WeakReference(i);
        i.M((ref S s_) => {
            Console.WriteLine("Entered M");

            GC.Collect();
            GC.WaitForPendingFinalizers();
            Console.WriteLine("WeakReference IsAlive: " + w.IsAlive);
            Console.WriteLine("WeakReference Target: " + w.Target);

            i = null;

            GC.Collect();
            GC.WaitForPendingFinalizers();
            Console.WriteLine("WeakReference IsAlive: " + w.IsAlive);
            Console.WriteLine("WeakReference Target: " + w.Target);

            // Console.WriteLine(s_);

            Console.WriteLine("Exiting M");
        });
    }
}