title: Twig: conditionally return from a macro
body: <p>I'd like to conditionally return from a macro, like this pseudocode:</p>
  
  <pre><code>{% macro example() %}
      ...
      {% if condition %} {% return %} {% endif %}
      ...
  {% endmacro %}
  </code></pre>
  
  <p>Is this possible with Twig, perhaps with a Twig extension?</p>