No because that would mean 'non-alphanumeric character followed by a non-whitespace character'. It would have to be written as (?:\W|\S).
If you mean could it be written as [\W\S] then that would match every character. If you imagine that \W is replaced with all characters that aren't alphanumeric (which means all whitespace and punctuation characters) and then replace \S with all non-whitespace characters (which would include all punctuation and alphanumeric characters) then you're left with all characters inside the character set (including punctuation characters twice).
Is it me or did I just completely overuse the word 'characters'?
