Challenge

gistfile1.rb

class TestUser
  def is_ok?
    true
  end

  def receive_message
    yield("message", self)
  end

  def &(other)
    TestUserGroup.new([self, other])
  end
end

class TestUserGroup
  attr_accessor :test_users

  def initialize(users)
    @test_users = users
  end

  def <<(other)
    @test_users << other
  end

  def &(other)
    self.class.new(@test_users + other)
  end

  def method_missing(method, *args, &block)
    @test_users.map do |test_user|
      test_user.send(method, *args, &block)      
    end
  end
end

me_gusta.rb

(bob & cindy).is_ok?
(bob & cindy).receive_message do |msg, user|
end

TestUser === bob.class
TestUserGroup === (bob & cindy).class

no_me_gusta.rb

[bob, cindy].each do |user|
  user.is_ok?
  user.receive_message do |msg|
  end
end

TestUser === bob.class