src/ArrayObject.php
public function getArrayCopyRec()
    {
        $ret = array();
        $it  = $this->getIterator();

        while ($it->valid()) {
            if ($it->current() instanceof self) {
                $ret[$it->key()] = $it->current()->getArrayCopyRec();
            } else {
                $ret[$it->key()] = $it->current();
            }

            $it->next();
        }

        return $ret;
    }
public function getArrayCopyRec()
    {
        $ret = array();
        $it  = $this->getIterator();

        while ($it->valid()) {
            if ($it->current() instanceof self) {
                $ret[$it->key()] = $it->current()->getArrayCopyRec();
            } else {
                $ret[$it->key()] = $it->current();
            }

            $it->next();
        }

        return $ret;
    }
Returns the multi-dimensional array structure with all instances of
ArrayObject transformed to standard PHP arrays

@return array Flattened array