Is it possible to define valid C# interface that cannot be implemented? [closed]

Answer 1

As long as we're talking trivia, I think this is a valid implementation of Eric Lippert's attempt:

class Program
{
    static void Main(string[] args)
    {
        D test = new D();
    }
}

class C
{
    private C() { }
}

interface IFoo where T : C, new() { }

class D : C
{
    public D()
        : this(5) { }

    public D(int x)
        : this() { }
}

class Dfoo : IFoo { }

It compiles fine but crashes with a StackOverflowException when you instantiate D.