Like OpenStruct but raises for anything not passed into the constructor.

closed_struct.rb

# Like OpenStruct but raises for anything not passed into the constructor.
# Unlike Struct in that it's built from a hash, and you don't need to define your own class.
#
# By Henrik Nyh <http://henrik.nyh.se> 2009-04-16. Public domain. 

require 'ostruct'
class ClosedStruct < OpenStruct
  def method_missing(symbol, *args)
    raise(NoMethodError, "undefined method `#{symbol}' for #{self}")
  end
end