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run code in 300+ PHP versions simultaneously
<?php readonly class A implements IteratorAggregate { function __construct(public string $foo = 'bar') {} function getIterator() : Traversable { return new ArrayIterator($this); } } $obj = new A; $v = &$obj->foo; $v = "baz"; var_dump($obj); // changed a readonly property
Output for 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
Fatal error: Uncaught Error: Cannot indirectly modify readonly property A::$foo in /in/OjiIC:12 Stack trace: #0 {main} thrown in /in/OjiIC on line 12
Process exited with code 255.
Output for 8.2.4 - 8.2.30, 8.3.5 - 8.3.30
Fatal error: Uncaught Error: Cannot modify readonly property A::$foo in /in/OjiIC:12 Stack trace: #0 {main} thrown in /in/OjiIC on line 12
Process exited with code 255.
Output for 8.1.30 - 8.1.34
Parse error: syntax error, unexpected token "readonly", expecting end of file in /in/OjiIC on line 3
Process exited with code 255.

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