Add Safe Navigation Operator as a ruby til.

README.md

@@ -209,6 +209,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 - [Question Mark Operator](ruby/question-mark-operator.md)
 - [Rake Only Lists Tasks With Descriptions](ruby/rake-only-lists-tasks-with-descriptions.md)
 - [Replace The Current Process With An External Command](ruby/replace-the-current-process-with-an-external-command.md)
+- [Safe Navigation Operator](ruby/safe-navigation-operator.md)
 - [Set RVM Default Ruby](ruby/set-rvm-default-ruby.md)
 - [Squeeze Out The Extra Space](ruby/squeeze-out-the-extra-space.md)
 - [Summing Collections](ruby/summing-collections.md)

ruby/safe-navigation-operator.md

@@ -0,0 +1,25 @@
+# Safe Navigation Operator
+
+With the release of Ruby 2.3, the *safe navigation operator* (`&.`) is now
+available. This addition to the Ruby language allows you to collapse all
+those pesky `nil` checks into the accessor call they are guarding. Consider
+this snippet of common Ruby code:
+
+```ruby
+if user && user.authenticate(params[:password])
+  # proceed with logged in user
+end
+```
+
+With the *safe navigation operator*, the predicate can now be collapsed:
+
+```ruby
+if user&.authenticate(params[:password])
+  # proceed with logged in user
+end
+```
+
+If `user` is `nil`, then the predicate will evaluate to `false` and the body
+of the if-statement will be passed over.
+
+[Source](http://nithinbekal.com/posts/ruby-2-3-features/)