What is the idiomatic way of cloning an array?

I had wondered about x.dup but am now worried this is not creating a shallow copy. I have seen people doing things with allocators, e.g. DStats – but am wondering if this is old code that should be excised.

-- 
Russel. ============================================================================= Dr Russel Winder      t: +44 20 7585 2200   voip: sip:russel.winder@ekiga.net 41 Buckmaster Road    m: +44 7770 465 077   xmpp: russel@winder.org.uk London SW11 1EN, UK   w: www.russel.org.uk  skype: russel_winder