Add instance methods class methods in one module

module.rb

module AttrLogger
  def log(msg)
    puts msg
  end

  module ClassMethods
    def attr_logger(name)
      attr_reader name
      define_method("#{name}=") do |val|
        puts "Assigning #{val.inspect} to #{name}"
        instance_variable_set("@#{name}", val)
      end
    end
  end


  def self.included(host_class)
    host_class.extend(ClassMethods)
  end
end

class Example
  include AttrLogger
  attr_logger :value
end