validates_with needs parameter

I read Active Record Validation section and tried to use
validates_with but i got number argument wrong error,
http://guides.rubyonrails.org/active_record_validations_callbacks.html#validates_with

when i looked into this doc, there is a parameter needed
http://api.rubyonrails.org/classes/ActiveModel/Validations/ClassMethods.html#method-i-validates_with

I think the guide is not correct

This is fixed in the latest changes. The guides will be updated when 3.1 is released.

Thanks for letting us know :slight_smile: