
Some of the changes to be found with the PHP 8.5 Alpha 1 development release include:
- Support for Closures and first-class callables in constant expressions.
- Support for backtraces on fatal errors.
- Adding the #[\NoDiscard] attribute to indicate a function's return value is important and should be consumed.
- Support for a (void) cast to indicate that not using a value is intentional.
- Support for casts in constant expressions.
- Added the pipe operator.
- Added array_first() and array_last().
- The PHP CLI binary now supports the "--ini=diff" option to print INI settings changed from the built-in default PHP settings.
PHP 8.5 is working its way toward the stable release in late November while until then will be multiple alpha and beta releases along with a few release candidates throughout October and November.

Downloads and more details on the PHP 8.5 Alpha 1 release via PHP.net .