.dup on an array of BitArray not duplicating

[ixid]

I'd typed the response before it displayed your reply that 
already answered the question. =) Sadly Array!bool doesn't seem 
to be memoizable, I assume memoization only sees container 
information or something like that. How would I go about creating 
an index accessible array using a struct of bits? Say for example 
I wanted it to be 250 bits long, rounded to the nearest 8. 
One-dimensional would be fine.