C# 8 base interface's default method invocation workaround

Question

According to https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/csharp-8.0/default-interface-methods It is possible to explicitly invoke an interface base implementation with the following syntax.

base(IInterfaceType).Method();

But this doesn't seem to be implemented yet.

Is there a workaround (e.g reflection) to achieve this?

---

Example code to illustrate the problem

interface IA
{
    void M()
    {
        Console.WriteLine("IA.M");
    }
}

interface IB : IA
{
    void IA.M()
    {
        Console.WriteLine("IB.M");
    }
}

interface IC : IA
{
    void IA.M()
    {
        Console.WriteLine("IC.M");
    }
}

class D : IA, IB, IC
{
    public void M()
    {
        // base(IB).M(); Is not yet supported apparently
        ((IB)this).M(); // Throws stack overflow
    }
}

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

Answer 1

This is a workaround. It isn't ideal. Perhaps it will help someone.

class C : IB
{
    public void IBM() => (this as IB).M();
}

class D : IA, IB, IC
{
    private C _c = new C();

    public void M()
    {
        _c.IBM();
    }
}