Listing all mixed in classes of a module

module_mixed_in_classes.rb

module MyModule
  def self.included base
    included_classes << base unless included_classes.include?(base)
  end
  
  def self.included_classes
    @@included ||= []
  end
end


class ClassA
  include MyModule
end

class ClassB
  include MyModule
end

puts MyModule.included_classes