Disable HTML escaping when manually rendering a Twig string

Question

I have the following code that renders a string into HTML output. How can I stop it from escaping the text for HTML?

$template = '{{ who }} bar';
$params = array('who' => "Foo's");

$twig = new \Twig_Environment(new \Twig_Loader_String);
var_dump($twig->render($template, $params));

Outputs:

string(14) "Foo's bar"

How can I make it output this instead?

string(14) "Foo's bar"

I understand that changing '{{ who }} bar' to '{{ who|raw }} bar' will fix the problem, but I want to solve this at the rendering stage. I do not want to change all of the templates.

Answer 1

I dug through the Twig code and found that this works fine:

$twig = new \Twig_Environment(new \Twig_Loader_String, array(
    'autoescape' => false
));