loophp / collection

src/Contract/Operation/Keyable.php

<?php

declare(strict_types=1);

namespace loophp\collection\Contract\Operation;

/**
 * @template TKey
 * @template T
 */
interface Keyable
{
    /**
     * Get the key of an item in the collection given a numeric index, default index is 0.
     *
     * @see https://loophp-collection.readthedocs.io/en/stable/pages/api.html#key
     *
     * @return TKey|null

The type loophp\collection\Contract\Operation\TKey was not found. Maybe you did not declare it correctly or list all dependencies?

     */
    public function key(int $index = 0);
}