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run code in 300+ PHP versions simultaneously
<?php function foo(mixed $arg): mixed { echo 'foo'; } foo('arg');
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.31, 8.2.0 - 8.2.27, 8.3.0 - 8.3.15, 8.4.1 - 8.4.2
foo Fatal error: Uncaught TypeError: foo(): Return value must be of type mixed, none returned in /in/I5ipI:6 Stack trace: #0 /in/I5ipI(8): foo('arg') #1 {main} thrown in /in/I5ipI on line 6
Process exited with code 255.
Output for 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33
Fatal error: Uncaught TypeError: Argument 1 passed to foo() must be an instance of mixed, string given, called in /in/I5ipI on line 8 and defined in /in/I5ipI:3 Stack trace: #0 /in/I5ipI(8): foo('arg') #1 {main} thrown in /in/I5ipI on line 3
Process exited with code 255.

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