Thanks for tracking down all that info. It would appear my concerns about perldoc.perl.org not being up-to-date are unfounded.

"Of course, you don't need to wait for Perl 5.20.0 to use these functions; List::Util 1.38 is already on CPAN."

Actually, I don't have to wait or, indeed, do anything at all. :-)

As stated above:

"... my versions: List::Util 1.38 and Perl 5.18.1"

I didn't (deliberately) install List::Util 1.38, so it must have been a dependency of some other module I installed via cpan.