fun1.rb

module ClassHook
  extend_object Class

  def new(sclass = Object, *args)
    super(sclass.to_class, *args)
  end
end

module ModuleHook
  append_features Module

  def to_class
    return self if self.is_a? Class
    mixin = self
    Class.new { include mixin }
  end
end

class Foo < Comparable
end

p Foo.ancestors # [Foo, #<Class:0xb88>, Comparable, Object, Kernel]

fun2.rb

module ClassHook
  extend_object Class

  def new(sclass = Object, *args)
    super(sclass.to_class, *args)
  end
end

module ModuleHook
  append_features Module

  def to_class(superclass = Object)
    return self if self.is_a? Class
    mixin = self
    Class.new(superclass) { include mixin }
  end
end

Module.send :alias_method, :<, :to_class

class Foo < Comparable < Enumerable
end

p Foo.ancestors # [Foo, #<Class:0xb88>, Comparable, #<Class:0xb8a>, Enumerable, Object, Kernel]