1--TEST-- 2Closure 019: Calling lambda using $GLOBALS and global $var 3--FILE-- 4<?php 5 6$lambda = function &(&$x) { 7 return $x = $x * $x; 8}; 9 10function test() { 11 global $lambda; 12 13 $y = 3; 14 var_dump($GLOBALS['lambda']($y)); 15 var_dump($lambda($y)); 16 var_dump($GLOBALS['lambda'](1)); 17} 18 19test(); 20 21?> 22--EXPECTF-- 23Notice: Only variable references should be returned by reference in %sclosure_019.php on line 4 24int(9) 25 26Notice: Only variable references should be returned by reference in %sclosure_019.php on line 4 27int(81) 28 29Fatal error: Uncaught Error: {closure:%s:%d}(): Argument #1 ($x) could not be passed by reference in %s:%d 30Stack trace: 31#0 %s(%d): test() 32#1 {main} 33 thrown in %s on line %d 34