Transients in Ruby. Transients are a way to mutate an immutable object for a limited scope of changes and then make it immutable again.

transients.rb

class Object
  def transient(&block)
    dup.tap(&block).freeze
  end
end

str = "hey".freeze

new_str = str.transient do |mutable_str|
  mutable_str.upcase!
end

p new_str == "HEY"
p new_str.frozen? == true

@dkubb Mayte that would make sense for adamantium? Dunno a use case for myself, because I normally use Anima#update.