$smcFunc += array(
        'entity_fix' => create_function('$string', '
            $num = substr($string, 0, 1) === 'x' ? hexdec(substr($string, 1)) : (int) $string;
            return $num < 0x20 || $num > 0x10FFFF || ($num >= 0xD800 && $num <= 0xDFFF) || $num == 0x202E ? '' : '&#' . $num . ';';'),

        'htmlspecialchars' => create_function('$string, $quote_style = ENT_COMPAT, $charset = 'ISO-8859-1'', '
            global $smcFunc;
            return ' . strtr($ent_check[0], array('&' => '&')) . 'htmlspecialchars($string, $quote_style, ' . ($utf8 ? ''UTF-8'' : '$charset') . ')' . $ent_check[1] . ';'),

        'htmltrim' => create_function('$string', '
            global $smcFunc;
            return preg_replace('~^(?:[ tnrx0Bx00' . $space_chars . ']|&nbsp;)+|(?:[ tnrx0Bx00' . $space_chars . ']|&nbsp;)+$~' . ($utf8 ? 'u' : '') . '', '', ' . implode('$string', $ent_check) . ');'),

        'strlen' => create_function('$string', '
            global $smcFunc;
            return strlen(preg_replace('~' . $ent_list . ($utf8 ? '|.~u' : '~') . '', '_', ' . implode('$string', $ent_check) . '));'),

        // ...
    );

'entity_fix' => function($string) use ($num) {
    $num = 0 === strpos($string, 'x') ? hexdec(substr($string, 1)) : (int) $string;
    return $num < 0x20 || $num > 0x10FFFF || ($num >= 0xD800 && $num <= 0xDFFF) || $num == 0x202E
        ? ''
        : '&#' . $num . ';';
},