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run code in 150+ php & hhvm versions
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<?php function f(&$a) {} function g($a) { $v = $a; return $v; } $a = function() {}; array(&$a("a")); f(g(3));
Output for 5.3.0 - 5.5.3
Fatal error: Can't use function return value in write context in /in/W132q on line 8
Process exited with code 255.