Generating all combinations of length X in an array

[wobbles via Digitalmars-d-learn]

On Wednesday, 8 April 2015 at 10:54:45 UTC, bearophile wrote:
> wobbles:
>
>> While trying to generate all combinations of length X in an 
>> array,
>> I came across the question on stackoverflow. [1]
>>
>> Theres a couple good answers there, but one that caught my eye 
>> shows a C# code snippet that is quite nice and short:
>
> Often short code is not the best code.
>
> Take a look at the versions here, the usable one is the third:
> http://rosettacode.org/wiki/Combinations#D
>
> Bye,
> bearophile

Ah, excellent! Dunno why I didnt think of rosettacode before.

Is the 3rd version usable at compile time?

Thanks, all the D stuff on rosettacode is an excellent resource!