Count the items from a IEnumerable without iterating?

private IEnumerable<string> Tables
{
    get
    {
        yield return "Foo";
        yield return "Bar";
    }
}

Let’s say I want iterate on those and write something like processing #n of #m.

Is there a way I can find out the value of m without iterating before my main iteration?

I hope I made myself clear.