Set::Array allows you to create arrays as objects and use OO-style
methods on them. Many convenient methods are provided here that appear
in the FAQ's, the Perl Cookbook or posts from comp.lang.perl.misc. In
addition, there are Set methods with corresponding (overloaded)
operators for the purpose of Set comparison, i.e. +, ==, etc.

WWW: http://search.cpan.org/dist/Set-Array/