Making enum join variadic

["Nordlöw" via Digitalmars-d-learn]

On Friday, 2 May 2014 at 14:36:16 UTC, Meta wrote:
> On Friday, 2 May 2014 at 13:38:39 UTC, Nordlöw wrote:
>> enums.d(25,46): Error: static variable allMembers cannot be 
>> read at compile time
>> enums.d(25,21):        while evaluating: static assert("a" in 
>> allMembers)
>>
>> Is there a solution to this problem?
>
> Associative arrays are not CTFE-able.

So that leaves me with using an array of bool and rank() then, I 
guess...