Exception or Error Messages

Question

I am having a dilemma in designing a function that returns a double value.

The function is performing some calculation and designed as follows:

double SimpsonIntegration(const Function& f, float a, float b,int n,std::string& ErrorMessages)
if(n%2!=0)
{
    ErrorMessages=ErrorMessages+"Simpson Integration: Number of subintervals must be even number\n";
}else if(n<20||n>100)
{
    ErrorMessages=ErrorMessages+"Simpson Integration: Number of subintervals should be between 20 to 100\n");
}

double h=0,x=0,y=0,retVal=0;

My dilemma is if there is an error I do not want to proceed to double h=0 .... line and want to return from the function asap. However, since it is designed to return double, I can not just simply use a return expression. I have thought about using a goto statement to go end of the function or throw errors instead of using an error message string. But if I throw error and forget to catch it, it will simply terminate the program and unfortunately C++ does not have a mechanism to remind programmer that a function throws error and must be caught by the caller.

What type of design would you recommend to handle errors? Thanking you in advance.

You and your team have to agree on a policy and stick to it. There are pros and cons to both ways. — R Sahu, Jun 27 '14 at 23:43
You can throw an exception or perhaps if exceptions are not available to you something like `boost::optional` might do what you want. — shuttle87, Jun 27 '14 at 23:44
Why does the programmer need reminding? Surely if her program terminates, she'll figure out that there was a problem.... — Kerrek SB, Jun 27 '14 at 23:45

score 0 · Answer 1 · answered Jun 27 '14 at 23:44

If the error must not be ignored - use a throw-catch.

If an error can be ignored (doesn't seem to be your case though)you have two options:

Use a separate pass-by-reference parameter for the error code
Return the error code (or a code for success) and use a pass-by-reference parameter to return the actual result

Exception or Error Messages

1 Answers1