I don't understand the code in the examples after simply reading it. That's a problem. You need to have comments to clarify or pick a better example of code.

You are in competition with Python and Javascript which has lots of code for training data. I wouldn't touch esoteric features unless it improves readability or is under the hood. The bigger problem with esoteric features is that its hard for humans in general to understand unless you cover it with enough syntactic sugar for people to write it down.