<?php
function pop($f) {
echo $f;
}
function hop(Callable $on = NULL) {
if (!is_string($on)) {
echo "no pat no, don't sit on that";
}
}
hop('pop');
hop(NULL);
Catchable fatal error: Argument 1 passed to hop() must be an instance of Callable, string given, called in /in/L5qPA on line 11 and defined in /in/L5qPA on line 5
Process exited with code 255.
Output for 5.1.0 - 5.1.6
Fatal error: Argument 1 passed to hop() must be an object of class Callable, called in /in/L5qPA on line 11 and defined in /in/L5qPA on line 5
Process exited with code 255.
Output for 5.0.0 - 5.0.5
Fatal error: Argument 1 must be an object of class Callable in /in/L5qPA on line 5
Process exited with code 255.
Output for 4.4.2 - 4.4.9
Parse error: syntax error, unexpected T_STRING, expecting ')' in /in/L5qPA on line 5
Process exited with code 255.