Ruby: Is it possible to define a class method in a module?

Question

Say there are three classes: A, B & C. I want each class to have a class method, say self.foo, that has exactly the s

Answer 1

Rails 3 introduced a module named ActiveSupport::Concern which has the goal of simplifying the syntax of modules.

module Foo
  extend ActiveSupport::Concern

  module ClassMethods
    def some_method
      # stuff
    end
  end
end

It allowed us to save a few lines of "boilerplate" code in the module.