I have just upgraded to Mongoid 3.0x in my new project and a few things have broken.

One in particular is my has_and_belongs_to_many relationship used to have an 'as' clause but now that doesn't work.

How should I implement models where (for example) a Band can have both musicians and fans? I tried something like this but it's not right. The docs are alas out of date in this respect.

class Band
include Mongoid::Document
field :name, type: String
has_and_belongs_to_many :musicians, as: :member_of, class_name: "User"
has_and_belongs_to_many :fans, as: :fan_of, class_name: "User"

end

class User
include Mongoid::Document
field :name, type: String
has_and_belongs_to_many :bands, as: :member
has_and_belongs_to_many :bands, as: :fan

end

Sorry if this is a noob question, today is my first day with MongoDB and Mongoid.