PHP 7.1 will have a neat function to create closures from callables. Joseph Silber explains the function and offers some good examples on his blog.

With PHP 5.5 going EOL earlier this week and the PHP 7.1 beta expected later this month, now sounds like a good time to look into a neat little feature coming in 7.1: easily converting any callable into a proper Closure using the new Closure::fromCallable() method.
  • A short refresher on closures in PHP
  • When you need to convert a callable to a Closure
  • Introducing Closure::fromCallable()
  • Creating a closure that wraps a private method

https://josephsilber.com/posts/2016/07/13/closure-from-callable-in-php-7-1