What is a "yield return" equivalent in the D programming language?

Here is a simple generator in C#.

    IEnumerable<int> Foo()
    {
        int a = 1, b = 1;
        while(true)
        {
            yield return b;
            int temp = a + b;
            a = b;
            b = temp;
        }
    }

How do I write a similar generator in Digital Mars D?

(The question is about the yield return statement)

Thanks!

Update. That's interesting. Since I'm just generating a mathematical sequence, using recurrence may be a good option.

auto fib = recurrence!("a[n-1] + a[n-2]")(1, 1);

foreach (e; take(fib, 10)) // <- prints first ten numbers from the sequence
{ 
    writeln(e); 
}