"||" operator ? : Is there a corresponding operator for iterables ?

[cblake]

I happened to just be adding some very preliminary "guts" for [a 
module](https://github.com/c-blake/cligen/blob/master/cligen/procpool.nim) 
similar to Python's `multiprocessing` to wrap an MT-UNSAFE C facility when I 
noticed this question. No `||` operator yet, but maybe someday. (It is a 
slightly different topic, of course, since parent-child sharing is more 
restricted, but perhaps of interest.)