Multibyte trim in PHP?

Question

Apparently there\'s no mb_trim in the mb_* family, so I\'m trying to implement one for my own.

I recently found this regex in a comment in php.net:

Answer 1

This version supports the second optional parameter $charlist:

function mb_trim ($string, $charlist = null) 
{   
    if (is_null($charlist)) {
        return trim ($string);
    } 

    $charlist = str_replace ('/', '\/', preg_quote ($charlist));
    return preg_replace ("/(^[$charlist]+)|([$charlist]+$)/us", '', $string);
}

Does not support ".." for ranges though.