Issue #19693 has been updated by nobu (Nobuyoshi Nakada). This is a kind of cheat, but... https://github.com/nobu/ruby/tree/data-optimize --- compare-ruby: ruby 3.3.0dev (2023-05-26T17:07:47Z master c6e4337a99) [x86_64-darwin22] built-ruby: ruby 3.3.0dev (2023-05-27T10:07:26Z data-optimize 81baba152b) [x86_64-darwin22] last_commit=[Misc #19693] Optimize Data.new warming up.... ##### Iteration per second (i/s) | |compare-ruby|built-ruby| |:------------|-----------:|---------:| |Struct-list | 7.194M| 7.169M| | | 1.00x| -| |Struct-kwd | 933.437k| 925.462k| | | 1.01x| -| |Data-list | 921.171k| 9.232M| | | -| 10.02x| |Data-kwd | 944.031k| 946.684k| | | -| 1.00x| ---------------------------------------- Misc #19693: Data initialization is significantly slower than Struct https://bugs.ruby-lang.org/issues/19693#change-103327 * Author: janosch-x (Janosch Müller) * Status: Closed * Priority: Normal ---------------------------------------- Maybe there is potential to make it as fast as Struct? ```ruby require 'benchmark/ips' S = Struct.new(:a, :b, :c, :d, :e, :f, :g, :h, :i, :j) D = Data.define(:a, :b, :c, :d, :e, :f, :g, :h, :i, :j) Benchmark.ips do |x| x.report('Struct') { S.new(1, 2, 3, 4, 5, 6, 7, 8, 9, 10) } x.report('Data') { D.new(1, 2, 3, 4, 5, 6, 7, 8, 9, 10) } x.compare! end; 1 # => [...] # => Struct: 6916530.4 i/s # => Data: 1507259.5 i/s - 4.59x slower ``` -- https://bugs.ruby-lang.org/