Parse error: syntax error, unexpected '->' (T_OBJECT_OPERATOR)

Controller

<?php
public function indexAction()
    {
        $item = new \stdClass();
        $item->var1 = '1';
        $item->var2 = '2';
        $item->var4 = '3';
        $test = array(
            'item' =>  $item
        );
        $this->view->setVars(array(
            'test' => $test
        ));
    }

Volt template

{{ dump(test['item'].var1) }}

Code generated in cache

<?php echo var_dump(($test['item'])->var1); ?>

Volt template

{{ test['item'].var1 }}

Code generated in cache

<?php echo ($test['item'])->var1; ?>

I get ( ! ) Parse error: syntax error, unexpected '->' (T_OBJECT_OPERATOR), expecting ',' or ';' in /work/nested-set/tree/app/cache/_work_nested-set_tree_app_views_index_index.volt.php on line 26

In Controller all works as usual

var_dump($test['item']->var1); //1

My question is there is a bug or my mistake?

This structure works as expected

{% for t in tree %}
    {% set a = t["item"] %}
    {{ a.getName() }}
{% endfor %}

But why do I have create another variable for getting object property?

Thanks