int 
MyLib::strToInt(passfailSV)
    SV* passfailSV
PREINIT:
    bool passfail;
CODE:
    RETVAL = THIS->strToInt(&passfail);
    SvSetMagicSV(passfailSV, passfail ? &PL_sv_yes : &PL_sv_no);
OUTPUT:
    RETVAL