Thomas Hanning outlines how to use the new defer keyword in Swift in his blog post.

Essentially, the defer keyword executes its block before exiting the scope it is contained within. It’s a great tool to ensure you do any clean-up code required, even if an error is thrown.

It’s almost like a deinit() block for your own functions!

Check out his full post here: http://www.thomashanning.com/swift-2-0-defer/