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Re: [PHP] Extending SplDoublyLinkedList with specific child types and avoiding strict notices




I don't believe this is possible due to not being able to narrow type hints
for arguments in extended classes. However, you could just remove the
typehint, and check yourself, something like:

        public class push($item)
        {
                if (!($item instanceof SpecificChildTypeClass::class))
                    throw new TypeError(sprintf(
                        'Argument 1 passed to %s::push() must be of the
type %s, %s given',
                       static::class,
                       SpecificChildTypeClass::class,
                       gettype($item) != 'object' ? gettype($item) :
get_class($item)
                    ));
                parent::push($item);
        }

On Mon, Mar 20, 2017 at 12:57 PM, AshleySheridan <ash@xxxxxxxxxxxxxxxxxxxx>
wrote:

> Hopefully the title says it all. Basically I'm extending the
> SplDoublyLinkedList as it's better on memory than arrays, is object
> orientated, and it can be extended with additional functionality more
> easily. It's that last part that is causing some issues. I'm extending
> to create a list class that only takes specific children. This example
> will throw PHP strict notices when run, which I ideally want to avoid:
>
> <?php
> class SomeSpecificListClass extends \SplDoublyLinkedList
> {
>         public class push(SpecificChildTypeClass $item)
>         {
>                 parent::push($item);
>         }
> }
>
> Has anyone else tried something like this before and found a better
> way?
>
>
> Thanks,
> Ash
>
> http://www.ashleysheridan.co.uk
>
>
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