Write a function which takes an argument and returns the number of non-alphanumeric characters found.
Write a function which takes an argument and returns the number of bytes used to store the number of non-alphanumeric characters found. (ie: include calculation for multi-byte characters.)
Rules / Notes
Alphanumeric in this case is defined as:
A null character should count as 0 characters, but as 1 byte when stored.
Showing multi-byte support (if too complicated) only has to demonstrate one character set or language reference / codepage (if this actually matters. I don't know, so just putting it out there.)
Since this is code golf, the shortest code that correctly matches the challege wins.