PHP 8.1 requires the offsetGet function to be compatible with the ArrayAccess declaration, i.e. to have a mixed return type. Without this, the Chain library produces deprecation notices like this:
PHP Deprecated: Return type of Cocur\Chain\AbstractChain::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in .../vendor/cocur/chain/src/AbstractChain.php on line 46
Mixed type is only available in PHP 8, Chain supports 7.2, so the only way to meet the new requirements is to add the #[\ReturnTypeWillChange] attribute.
PHP 8.1 requires the offsetGet function to be compatible with the ArrayAccess declaration, i.e. to have a mixed return type. Without this, the Chain library produces deprecation notices like this:
Mixed type is only available in PHP 8, Chain supports 7.2, so the only way to meet the new requirements is to add the
#[\ReturnTypeWillChange]attribute.