Issue #19787 has been reported by joshuay03 (Joshua Young). ---------------------------------------- Feature #19787: Add Enumerable#uniq_map, Enumerable::Lazy#uniq_map, Array#uniq_map and Array#uniq_map! https://bugs.ruby-lang.org/issues/19787 * Author: joshuay03 (Joshua Young) * Status: Open * Priority: Normal ---------------------------------------- I would like to propose a collection of new methods, `Enumerable#uniq_map`, `Enumerable::Lazy#uniq_map`, `Array#uniq_map` and `Array#uniq_map!`. TL;DR: It's a drop in replacement for `.map { ... }.uniq`, with better performance. I've quite often had to map over an array and get its unique elements. It occurred to me when doing so recently that Ruby doesn't have a short form method for doing that, similar to how `flat_map { ... }` replaces `.map { ... }.flatten` and `filter_map { ... }` replaces `.map { ... }.compact` (with minor differences). I think these new methods could be beneficial both in terms of better performance and writing more succinct code. I have already got a draft PR up with some initial benchmarks in the description: https://github.com/ruby/ruby/pull/8140. -- https://bugs.ruby-lang.org/