String/Hash/Array self-destruction

self_destruct.rb

# Considered adding this to Object, but that's a much more complex job. This gets the work done.

class Hash
  def self_destruct!
    self.each do |k,v|
      v.self_destruct! if v.respond_to? :self_destruct!
      self[k] = nil
      self.delete k
    end
  end
end

class Array
  def self_destruct!
    self.each_with_index do |v,i|
      v.self_destruct! if v.respond_to? :self_destruct!
      self[i] = nil
      self.delete i
    end
  end
end

class String
  def self_destruct!
    return if self.empty?
    ObjectSpace.each_object(String).select { |o| o == self }.each do |string_copy|
      next unless string_copy.object_id != self.object_id
      next if string_copy.frozen?
      string_copy.replace ""
    end
    self.replace ""
  end
end