guid

static VALUE
foletypelib_guid(VALUE self)
{
    struct oletypelibdata *ptlib;
    ITypeLib *pTypeLib;
    HRESULT hr;
    OLECHAR bstr[80];
    VALUE guid = Qnil;
    int len;
    TLIBATTR *pTLibAttr;
    Data_Get_Struct(self, struct oletypelibdata, ptlib);
    pTypeLib = ptlib->pTypeLib;
    hr = pTypeLib->lpVtbl->GetLibAttr(pTypeLib, &pTLibAttr);
    if (FAILED(hr)) {
        ole_raise(hr, eWIN32OLERuntimeError, "failed to GetLibAttr from ITypeLib");
    }
    len = StringFromGUID2(&pTLibAttr->guid, bstr, sizeof(bstr)/sizeof(OLECHAR));
    if (len > 3) {
        guid = ole_wc2vstr(bstr, FALSE);
    }
    pTypeLib->lpVtbl->ReleaseTLibAttr(pTypeLib, pTLibAttr);
    return guid;
}