Dynamic hash

dynamic_hash.rb

class DynamicHash < Hash
  def []=(key, val)
    super
    self.class.class_eval do
      define_method(key) do
        self[key]
      end
      define_method("#{key}=") do |value|
        self[key] = value
      end
      self
    end
  end
end

dh = DynamicHash.new

dh["foo"] = "bar"
p dh.foo