Ruby implementation of queue

queue.rb

class Queue
  def initialize(max_size=nil)
    @max_size ||= Float::INFINITY
    @store = []
  end

  def enqueue(item)
    raise "The queue is full" if self.full?
    @store << item
  end

  def dequeue
    raise "The queue is empty" if self.empty?
    @store.shift
  end

  def empty?
    @store.empty?
  end

  def full?
    @store.size == @max_size
  end
end