class_and_module_methods.rb

def modules_including_module(target_module)
  ObjectSpace.each_object(Module).select do |object|
    # All Class'es are modules, but we are not interested in them, so we exclude them.
    !object.is_a?(Class) \
      && \
      object.ancestors.include?(target_module) \
      && \
      !object.equal?(target_module)
  end
end
module_function :modules_including_module

def classes_including_modules(modules)
  ObjectSpace.each_object(Class).select do |klass|
    (klass.ancestors & modules).any?
  end
end
module_function :classes_including_modules

def classes_not_having_ancestor(classes, ancestor)
  classes.select do |klass|
    !klass.ancestors.include?(ancestor)
  end
end
module_function :classes_not_having_ancestor