Crystal-lang simple delegator

delegate.cr

class Delegator(T)
  def initialize(@object : T)
  end

  def self.delegate(object)
    new(object)
  end

  forward_missing_to @object
end

class Person
  def greet
    puts "Hi"
  end
end

class PersonDelegator < Delegator(Person)
  def greet_twice
    2.times do greet end # call Person class method
  end
end

person = Person.new()
person = PersonDelegator.delegate(person)
person.greet_twice # => Print "Hi" two times

person = Person.new()
person = Delegator(Person).new(person)
person.greet # "Hi"