From: shevegen@... Date: 2019-12-17T14:32:00+00:00 Subject: [ruby-core:96289] [Ruby master Feature#16428] Add Array#uniq? Issue #16428 has been updated by shevegen (Robert A. Heiler). > I often need to check if an array have duplicate elements. Makes sense to me; I have had situations where I needed this too in the past (including situations for non-unique entries in an Array), so I agree on the general use case opportunities in this regard. ---------------------------------------- Feature #16428: Add Array#uniq? https://bugs.ruby-lang.org/issues/16428#change-83194 * Author: kyanagi (Kouhei Yanagita) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- I propose Array#uniq?. I often need to check if an array have duplicate elements. This method returns true if no duplicates are found in self, otherwise returns false. If a block is given, it will use the return value of the block for comparison. This is equivalent to `array.uniq.size == array.size`, but faster. ``` % ~/tmp/r/bin/ruby -rbenchmark/ips -e 'a = Array.new(100) { rand(1000) }; Benchmark.ips { |x| x.report("uniq") { a.uniq.size == a.size }; x.report("uniq?") { a.uniq? } }' Warming up -------------------------------------- uniq 25.765k i/100ms uniq? 76.544k i/100ms Calculating ------------------------------------- uniq 278.144k (� 4.1%) i/s - 1.391M in 5.010858s uniq? 981.868k (� 5.1%) i/s - 4.975M in 5.081611s ``` I think the name `uniq?` is natural because Array already has `uniq`. patch: https://github.com/ruby/ruby/pull/2762 -- https://bugs.ruby-lang.org/ Unsubscribe: