//{{XLP_SRC(OperIsErrorExample) 
    // NOTE - the FunctionWizard will add and remove mapping code here. 
    //    DO NOT EDIT what you see in these blocks of generated code!
IMPLEMENT_XLLFN3(OperIsErrorExample, OperIsErrorExample_4, 
    OperIsErrorExample_12, "RP", "UQ", L"OperIsErrorExample", 0, L"Arg1", 0, 
    L"Example", 0, L"Demonstrates COper::IsError()", 0, L"Argument 1\0", 0, 0, 
    L"{OperIsErrorExample,,,Demonstrates COper::IsError(),Example,1,128,U,{{0,"
    L"{Arg1,Value,0,,Argument 1,,,,}}},{},3,,0,0}", 1)
CXlOper* OperIsErrorExample_Impl(CXlOper&, const CXlOper*);

extern "C" __declspec(dllexport)
LPXLOPER12 OperIsErrorExample_12(LPXLOPER12 Arg1)
{
    XLL_FIX_STATE;
    CXlOper xloResult, Arg1__port(Arg1);
    try {
        CXlStructuredExceptionHandler _seh_;
        xloResult.HandleResult(OperIsErrorExample_Impl(xloResult, &Arg1__port));
    }
    catch(const CXlRuntimeException& ex) {
        CXllApp::Instance()->DisplayException(xloResult, ex);
    }
    return xloResult.Ret12();
}
extern "C" __declspec(dllexport)
LPXLOPER4 OperIsErrorExample_4(LPXLOPER4 Arg1)
{
    XLL_FIX_STATE;
    CXlOper xloResult, Arg1__port(Arg1);
    try {
        CXlStructuredExceptionHandler _seh_;
        xloResult.HandleResult(OperIsErrorExample_Impl(xloResult, &Arg1__port));
    }
    catch(const CXlRuntimeException& ex) {
        CXllApp::Instance()->DisplayException(xloResult, ex);
    }
    return xloResult.Ret4();
}

CXlOper* OperIsErrorExample_Impl(CXlOper& xloResult, const CXlOper* Arg1)
{
    // End of generated code 
//}}XLP_SRC

    xloResult = Arg1->IsError();
    return xloResult.Ret();
}

Uses

CXlOper::IsError