constant

constant checks if a variable has the exact same value as a constant. You can use either global constants or class constants:

{% if post.status is constant('Post::PUBLISHED') %}
    the status attribute is exactly the same as Post::PUBLISHED
{% endif %}

You can test constants from object instances as well:

{% if post.status is constant('PUBLISHED', post) %}
    the status attribute is exactly the same as Post::PUBLISHED
{% endif %}