In this code
<?php declare(strict_types=1);
namespace Persist;
trait IteratorTrait {
/* #region Iterator */
/** @var bool $valid true if a valid object */
private bool $valid = false;
public function current ( ): object { return $this; }
public function key ( ): mixed { return $this-> {$this->getPrimaryKey()} ; }
public function valid ( ): bool { return $this-> valid; }
public function next ( ): void { $this-> findNext(); }
public function rewind ( ): void { $this-> findFirst(); }
/* #endregion */
};
I get an error (on php 7.5) in an class that uses the trait: AH01071: Got error 'PHP message: PHP Fatal error: Uncaught TypeError: Return value of NameSpace\\test::key() must be an instance of mixed, int returned in...
If remove the :mixed on key I get an error on PHP 8.1: PHP Deprecated: Return type of NameSpace\test::key() should either be compatible with Iterator::key(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in ...
What I read here confuses me.
If I add this to the trait I get Fatal error: Attribute "ReturnTypeWillChange" cannot target property (allowed targets: method) in IteratorTrait.php on line 10
EDIT: This error occured because there was a property defined before the key() method.
Where should I change what to get this working on both 7.x and 8.x?
The
#[\ReturnTypeWillChange]
needs to appear directly before the method returning a mixed, but mixed needs to be ommitted to have this working in both PHP versions. The correct syntax is:Tested on PHP 8.1.5 and 7.4.29.