Phobos2: sorting and std.typecons.Tuple

[Andrei Alexandrescu]

bearophile wrote:
> dsimcha:
>> Vote++ for giving Tuple a decent default implementation of opCmp and toHash.
> 
> I have a much better idea (that I have expressed here more than one year ago): let's add good *recursive* opCmp, toHash, opEqual, toString to all structs.
> Similar "small" things are able to improve the flexibility of D2 a lot.

s/recursive/transitive/

Litmus test: recursive could recurse forever. Transitive never does.

Andrei