const_setter.rb

def ConstSetter(opts)
  (@@__const_setter__modules ||= {})[opts] ||= Module.new do |m|
    def m.included c
      @@__const_setter__modules.index(self).each do |key, val|
        c.const_set(key, val)
      end
    end
  end
end

class Test
  include ConstSetter(:TestConst => 123)
end

p Test::TestConst