--- /dev/null
+``constant``
+============
+
+.. versionadded: 1.13.1
+ constant now accepts object instances as the second argument.
+
+``constant`` checks if a variable has the exact same value as a constant. You
+can use either global constants or class constants:
+
+.. code-block:: jinja
+
+ {% 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:
+
+.. code-block:: jinja
+
+ {% if post.status is constant('PUBLISHED', post) %}
+ the status attribute is exactly the same as Post::PUBLISHED
+ {% endif %}