That's coming in PHP 5.7 anyhow. It's been implemented and works, but Nikita Popov hasn't had the time to change the function definitions of the standard library to work with it, hence PHP 5.6 won't have it, sadly.
Wow, I haven't kept up with things, but gosh that sounds pretty great. Type checking + named params is a fairly difficult combination of great language features to find in the same language.
