Rule no_short_bool_cast Short cast bool using double exclamation mark should not be used. Examples Example #1 --- Original +++ New <?php -$a = !!$b; +$a = (bool)$b; Rule sets The rule is part of the following rule sets: @PhpCsFixer @Symfony Source class PhpCsFixer\Fixer\CastNotation\NoShortBoolCastFixer