non-empty-string $pattern:
int-mask<PREG_UNMATCHED_AS_NULL> $flags PREG_UNMATCHED_AS_NULL is always set, no other flags are supported:
public static function match(string $pattern, string $subject, int $flags = 0, int $offset = 0) : MatchResult { self::checkOffsetCapture($flags, 'matchWithOffsets'); $count = Preg::match($pattern, $subject, $matches, $flags, $offset); return new MatchResult($count, $matches); }