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run code in 300+ PHP versions simultaneously
<?php function f(&$a) {} function g($a) { $v = $a; return $v; } f(3);
Output for 8.3.0 - 8.3.6
Fatal error: Uncaught Error: f(): Argument #1 ($a) could not be passed by reference in /in/K1M41:6 Stack trace: #0 {main} thrown in /in/K1M41 on line 6
Process exited with code 255.
Output for 8.1.23 - 8.1.28, 8.2.10 - 8.2.18
Fatal error: Uncaught Error: f(): Argument #1 ($a) cannot be passed by reference in /in/K1M41:6 Stack trace: #0 {main} thrown in /in/K1M41 on line 6
Process exited with code 255.
Output for 5.3.0 - 5.3.27, 5.4.0 - 5.4.19
Fatal error: Only variables can be passed by reference in /in/vZSO2 on line 6
Process exited with code 255.

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