class Object
  def destruct(*arg)
    instance_variables.map{ |k| k.to_s.split('@').last.to_sym }.select {|k| arg.include?(k)}.each do |k|
       main = TOPLEVEL_BINDING.eval("self")
       main.singleton_class.class_eval { attr_accessor "#{k}" }
       main.send("#{k}=", eval("#{k}"))
    end
  end
end

class Hash
  def destruct(*arg)
    select {|k| arg.include?(k)}.each do |k, v|
       main = TOPLEVEL_BINDING.eval("self")
       main.singleton_class.class_eval { attr_accessor "#{k}" }
       main.send("#{k}=", v)
    end
  end
end

class MyClass
  attr_reader :a
  def initialize
    @a = 'b'
  end
end

## EXAMPLES
my_class = MyClass.new
my_class.destruct(:a)
p a

hash = { a: 'b', b: 'a'}
hash.destruct(:b)
p b