[Challenge] implementing the ambiguous operator in D

[Peter Alexander]

== Quote from Andrei Alexandrescu (SeeWebsiteForEmail at erdani.org)'s article
> We've discussed this before. Crosscartesian product of multiple infinite
> ranges can be easily done by applying Cantor's trick for proving that
> rational numbers are just as numerous than natural numbers. Google for
> "Cantor" with "site:digitalmars.com".
> Andrei

Thanks.

For some reason I had just assumed that we would have wanted to provide the product in
lexicographic order, but Cantor's trick does seem like a solution to this problem.