disposable.rb

class DisposableHero
  include System::IDisposable
  attr :name
  def initialize(name = "Jed")
    @name = name
  end
  def do_something_to(other)
    puts "#{@name} washes a car for #{other.name}"
  end
  def do_something
    puts "#{@name} doing something"
  end
  def dispose
    puts "#{@name} is being disposed"      
  end
end

module System::IDisposable
  def self.use_these(*disposers, &block)
    block.call(*disposers)
  rescue
    disposers.each {|d| d.dispose}
  end
  def using(&block)
    block.call(self)
  rescue
    self.dispose
  end
end

DisposableHero.new.using do |d|
  d.do_something
end

System::IDisposable.use_these(DisposableHero.new("Tony"), DisposableHero.new("Ryan")) do |t, r|
  t.do_something_to(r)
end