ruby-sandbox ❯ ruby -v ruby 2.6.2p47 (2019-03-13 revision 67232) [x86_64-darwin18] Example ❯ irb irb(main):001:0> require './struct' => true irb(main):002:0> StructSandbox.basic_usage #<struct atk=100, def=50> "atk:100, def:50" => "atk:100, def:50"