From: "Student (Nathan Zook)" Date: 2013-02-08T07:47:36+09:00 Subject: [ruby-core:52011] [ruby-trunk - Feature #7796] Hash#keys should return a set Issue #7796 has been updated by Student (Nathan Zook). The first problem for me is that Hash is part of core while Set is part of the standard lib. One cannot have core depend on lib. The second problem is that hash#keys has returned an array for the entire history of Ruby. It is far from clear to me that breaking that assumption is a good idea. Now, Hash#key_set, defined when you do require 'set', has possibilities, if you have a use case. ---------------------------------------- Feature #7796: Hash#keys should return a set https://bugs.ruby-lang.org/issues/7796#change-36021 Author: alexeymuranov (Alexey Muranov) Status: Feedback Priority: Normal Assignee: Category: core Target version: Next Major =begin In my opinion, (({Hash#keys})) should return an instance of (({Set})). =end -- http://bugs.ruby-lang.org/