From: "lellisga (Li Ellis Galardo)" Date: 2012-06-04T14:36:40+09:00 Subject: [ruby-core:45415] [ruby-trunk - Feature #6515] array.c: added method that verifies if an Array is part of another Issue #6515 has been updated by lellisga (Li Ellis Galardo). Sorry but i'm not sure what you are asking. In other words you really think it's easier to do this: a = [1,2,3,4,5,6,7].to_set => # b = [1,2,3].to_set => # b.subset? a => true If you answer is yes, then we are doing this wrong because subset? or part_of method should be in a parent class (maybe Enumerable class ) in order for it to work for subset, array, hash and any data structure that inherit from it Enumerable. There's a difference between subset and arrays isn't it? they should have different methods, eventually some of them will work for subset just as they work for arrays. ---------------------------------------- Feature #6515: array.c: added method that verifies if an Array is part of another https://bugs.ruby-lang.org/issues/6515#change-27003 Author: lellisga (Li Ellis Galardo) Status: Feedback Priority: Normal Assignee: matz (Yukihiro Matsumoto) Category: Target version: 2.0.0 This method is like the include? method but instead of receiving a value and check if the array has it, it receives an array an check if it's part of another one. https://github.com/ruby/ruby/pull/127 -- http://bugs.ruby-lang.org/