gistfile1.txt

require 'classx'
  #=> true

require 'classx/util'
  #=> true
  
class Hoge < ClassX
  extend Util

  has_writer_with_default :x, 30
end
  #=> nil

Hoge.new 
  #=> #<Hoge:0x24428 @__attribute_of={"x"=><#ClassX::Attribute {:optional=>true, :writable=>true, :default=>30}:73230  >}>

hoge = Hoge.new
  #=> #<Hoge:0x1b184 @__attribute_of={"x"=><#ClassX::Attribute {:optional=>true, :writable=>true, :default=>30}:54850  >}>

hoge.x   
  #=> 30