Which Ruby memoize pattern does ActiveSupport::Memoizable refer to?

Question

So in Rails 3.2, ActiveSupport::Memoizable has been deprecated.

The message reads:

DEPRECATION WARNING: ActiveSupport::Memoizable is deprecated and will be removed in future releases,simply use Ruby memoization pattern instead. 

It refers to "Ruby memoization pattern" (singular) as if there's one pattern we should all know and refer to...

I presume they mean something like:

def my_method   @my_method ||= # ... go get the value end 

or

def my_method   return @my_method if defined?(@my_method)    @my_method = # ... go get the value end 

Is there something else I've missed?

Answer 1

Here is the commit (and subsequent discussion) where Memoizable was deprecated: https://github.com/rails/rails/commit/36253916b0b788d6ded56669d37c96ed05c92c5c

The author advocates the @foo ||= ... approach and points to this commit as an example for migration: https://github.com/rails/rails/commit/f2c0fb32c0dce7f8da0ce446e2d2f0cba5fd44b3.

Edit: Note that I don't necessarily interpret this change as meaning that all instances of memoize can or should be replaced w/ this pattern. I read it as meaning that Memoizable is no longer needed/wanted in the Rails code itself. As the comments point out, Memoizable is much more than just a wrapper around @foo ||= .... If you need those features, go ahead and use Memoizable, you'll just have to get it from somewhere other than ActiveSupport (I'm guessing someone will fork a gem version, if they haven't already).