TYPEMAP
wchar_t *                   T_WCHAR
const wchar_t *             T_WCHAR

INPUT
T_WCHAR
    $var = SvToWChar($arg);
    SAVEFREEPV($var);

OUTPUT
T_WCHAR
        {
          wchar_t* src;
          if (!$var)
            XSRETURN_UNDEF;
          src = (wchar_t*) $var;
          WCharToSv(src, (SV*)$arg);
        }