Aspose::Cells::Startup();

//Implement AbstractCalculationEngine interface
class CustomFunction1 : public AbstractCalculationEngine
{
public:
	void Calculate(CalculationData& data)
	{
	    Object funcName = data.GetParamValue(0);
		U16String cellName = data.GetCell().GetName();
		Object cellValue = data.GetParamValue(1);
		if (data.GetFunctionName() == u"MySampleFunc")
		{
			std::cout << funcName.ToString().ToUtf8() << " called successfully." << std::endl;
			data.GetCell().PutValue(cellValue);
		}

		if (data.GetFunctionName() == u"YourSampleFunc")
		{
			std::cout << funcName.ToString().ToUtf8() << " called successfully." << std::endl;
			data.GetCell().PutValue(cellValue);
		}
	}


};

//Create workbook
Workbook wb;

//Access first worksheet in the workbook
Worksheet ws = wb.GetWorksheets().Get(0);

//Adding custom formulas to Cell A1 and A2
ws.GetCells().Get(u"A1").SetFormula(u"=MySampleFunc(\"MySampleFunc-Test\",1)");
ws.GetCells().Get(u"A2").SetFormula(u"=YourSampleFunc(\"YourSampleFunc-Test\",2)");

// Calcualting Formulas
CustomFunction1 custFunc;
CalculationOptions options;
options.SetCustomEngine(&custFunc);
wb.CalculateFormula(options);

//Print the value of cell A1 and A2 after the calculation of custom function implemented by us.
U16String valA1 = ws.GetCells().Get(u"A1").GetStringValue();
U16String valA2 = ws.GetCells().Get(u"A2").GetStringValue();
std::cout << "Value of A1 is : " << valA1.ToUtf8() << std::endl;
std::cout << "Value of A2 is : " << valA2.ToUtf8() << std::endl;

Aspose::Cells::Cleanup();