Open2020/12/23にコメント追加2Ruby3.0を覗いてみるmoriq2020/12/23itoさんのまとめ記事 https://qiita.com/jnchito/items/bf8c6c2e1dd6cff05f4e moriq2020/12/23ruby lang公式 https://www.ruby-lang.org/en/news/2020/12/20/ruby-3-0-0-rc1-released/