How to walk over two arrays by ref in beautyfull way?

[vitalfadeev via Digitalmars-d-learn]

How to?

I plan scan First array with checkers:
[checker, checker, checker]

...and store result to Second array:
[0, 0, 1]

In next code 'r' not reference. But expected ref.

    import std.range : zip;

    foreach(checker, ref r; zip(checkers, result.set)) {
       r = checker();
    }

What is the best way for speed and beautyfull D code?