title: Using rails presenters - memoizable getting deprecated in 3.1 - use ||= instead?
body: <p>Issue: To avoid creating multiple objects or multiple queries when possible.</p>
  
  <p>I am using Presenters with rails as a Best Practice.</p>
  
  <p>I am following advice that says that it would be good to use "extend ActiveSupport.Memoizable" (and then memoize :method(s) to use them) over setting up items with <code>@the_record = record ||= @record</code> style because of a couple of issues - false or nil not getting stored so the query gets called again and also that memoizable uses the cache better (i.e. uses it!).</p>
  
  <p>However I see that memoizable is getting deprecated in rails 3.1
  Notes i github under carrierwave and with statement:
  "DEPRECATION WARNING: ActiveSupport::Memoizable is deprecated and will be removed in future releases,simply use Ruby memoization pattern instead. (called from extend at /Users/kain/.rvm/gems/ruby-1.9.3-preview1/bundler/gems/carrierwave-c4459179b0f8/lib/carrierwave/mount.rb:284".</p>
  
  <p>Maybe it's been resolved though? Anyone know?</p>
  
  <p>Any suggestions about the best practice to use going forward? Use the ||= syntax?  What about the above issues?</p>
  
  <p><img src="https://i.stack.imgur.com/ow25A.png" alt="enter image description here"></p>