Ruby's object model: eigenclasses, metaclasses, and more

Or, a Class class masterclass. One way or another, a famous question will cross every Rubyist’s mind, probably many times: what’s an eigenclass? In the Ruby docs, there’s a tremendous diagram under the page for class Class that made me think of this again: Classes, modules, and objects are interrelated. In the diagram that follows, the vertical arrows represent inheritance, and the parentheses…