SplDatastructure and invalid data

>>>>templates/test.tpl
<opt:section name="foo">
{$foo.item}
<opt:sectionelse>EMPTY</opt:sectionelse>
</opt:section>

>>>>data.php


$view->foo = array('foo' => 'bar');
$view->setFormat('foo', 'SplDatastructure');

>>>>expected.txt
OUTPUT

>>>>result.txt
EMPTY