PHP 8.0/8.1 Support

CI 3.1.13 is working with PHP 8.0.3 like a charm. With PHP 8.1.4 I get this error:

Message: ltrim(): Passing null to parameter #1 ($string) of type string is deprecated
Filename: core/URI.php
Line Number: 641

ORIGINAL:

PHP Code:

return ltrim(load_class('Router', 'core')->directory, '/').implode('/', $this->rsegments); 


CHANGED/WORKING:

PHP Code:

return ltrim((string)load_class('Router', 'core')->directory, '/').implode('/', $this->rsegments);