Sometimes, an options hash is better than a bunch of instance variables. But referring to things like options[:key] is annoying, as is setting things via options[:key] = ... Enter method_missing.

fake_attr_accessor

# If your options hash is stored in @options

attr_accessor :options

def method_missing(meth,*args,&prc)
  if options.keys.include?(meth.to_sym)
    options[meth.to_sym]
  elsif options.keys.include?(meth[0...-1].to_sym) && meth[-1] == "="
    options[meth[0...-1].to_sym] = args.first
  else
    super
  end
end

########## EXAMPLE USE ##########
class Cat
  attr_accessor :options

  def initialize
    @options = {firstname: "Octo", lastname: "Cat"}
  end

  def method_missing(meth,*args,&prc)
    if options.keys.include?(meth.to_sym)
      options[meth.to_sym]
    elsif options.keys.include?(meth[0...-1].to_sym) && meth[-1] == "="
      options[meth[0...-1].to_sym] = args.first
    else
      super
    end
  end
end

octocat = Cat.new
# => #<Cat:0x007f98658315f8 @options={:firstname=>"Octo", :lastname=>"Cat"}>

octocat.firstname
# => "Octo"

octocat.firstname = "Septa"
# => "Septa"

octocat
# => #<Cat:0x007f98658315f8 @options={:firstname=>"Septa", :lastname=>"Cat"}>