I am trying to run this Example #1 from this page: http://php.net/manual/en/language.exceptions.php
\Exception doesn't work for me but I found a solution.
I needed to replace try{}catch(Exception $e){} by try{}catch(Throwable $e){}.
For more information : https://trowski.com/2015/06/24/throwable-exceptions-and-errors-in-php7/