A toy version of OpenStruct, with no error checking

quick_and_dangerous_struct.rb

# Faster than OpenStruct, but liable to get your box pwned.
class QuickAndDangerousStruct
  def method_missing(name, *args)
    make_method(name)
    send name, *args
  end

  def make_method(name)
    name = name.to_s
    base = name.end_with?('=') ? name[0..-2] : name
    var = "@#{base}"
    eval <<-RUBY
    define_singleton_method base do
      #{var}
    end
    define_singleton_method "#{base}=" do |v|
      #{var} = v
    end
    RUBY
  end
end

quick_and_dirty_struct.rb

# Faster than OpenStruct at retrieving keys that don't exist and for
# setting keys, but slower than OpenStruct for getting keys that exist
class QuickAndDirtyStruct
  def method_missing(name, *args)
    make_method(name)
    send name, *args
  end

  def make_method(name)
    name = name.to_s
    base = name.end_with?('=') ? name[0..-2] : name
    var = "@#{base}".to_sym
    define_singleton_method base do
      instance_variable_get(var)
    end
    define_singleton_method "#{base}=" do |v|
      instance_variable_set(var, v)
    end
  end
end