Implementing Core Set
Jeremy Evans • Hakodate, Hokkaido, Japan • Talk

Held on: April 23, 2026
Published: not published

Historically, Ruby's Set class was in the standard library. Starting in Ruby 3.2, the Set standard library was autoloaded by default. In Ruby 4.0, Set is now implemented as one of the core classes. In this presentation, I'll go over the history of Set, why and how it was implemented as a core class, interesting implementation issues, and how it led to a decrease in memory usage for some embedded RTypedData objects (and what RTypedData objects are).

RubyKaigi 2026