How to alias a function in PHP?

Is it possible to alias a function with a different name in PHP? Suppose we have a function with the name sleep. Is there a way to make an alias called wait?

By now I'm doing like this:

function wait( $seconds ) {


PHP 5.6+ only

Starting with PHP 5.6 it is possible to alias a function by importing it:

use function sleep as wait;

There's also an example in the documentation (see "aliasing a function").