Two chunks but No allocation

[Salih Dincer via Digitalmars-d-learn]

Is it possible to process both chunks without requiring memory 
allocation (not using an array)?

For example:
```d
import std;
void main()
{
  auto fib = (real a, real b)
       => recurrence!"a[n-1] + a[n-2]"(a, b);

  auto myFib = fib(1, 1).take(48).array;
  auto goldenRadio = myFib.chunks(2).map!
  //"a[1] / a[0]";/* line #9
  ((a) {
    const m = a.front;
    a.popFront();
    const n = a.front;

    return m/n; });//*/

  goldenRadio.back.writefln!"%.21f";
  writeln("0.61803398874989484820");
}
```

Of course, it also works if you remove the comment marks on line 
#9 but I'm still using .array because the .chunks error tells me 
that.

So, not works this:

```d
fib(1, 1).take(48)
         //.array
         .chunks(2)
         .map!"a[1] / a[0]"
         .back
         .writeln; // 1.61803
```

Thanks...

SDB@79