New in Twig 3.15 (part 1) (Symfony Blog)
symfony.com
Twig 3.15 adds inline comments, the enum() function, the xor operator, improved operator precedence, JSON escaping, the guard tag, and enhanced deprecation handling.

Twig 3.15 was released a few weeks ago and includes an impressive list of new features and improvements. This two-part blog post highlights the most important ones.

Edit: Part 2