Question

Let me start by saying that I do not advocate this approach, but I saw it recently and I was wondering if there was a name for it I could use to point the guilty party to. So here goes.

Now you have a method, and you want to return a value. You also want to return an error code. Of course, exceptions are a much better choice, but for whatever reason you want an error code instead. Remember, I’m playing devil’s advocate here. So you create a generic class, like this:

class FunctionResult<T> {     public T payload;     public int result; } 

And then declare your functions like this:

FunctionResult<string> MyFunction() {     FunctionResult<string> result;     //...      return result; } 

One variation on this pattern is to use an enum for the error code instead of a string. Now, back to my question: is there a name for this, and if so what is it?

Answer 1

I’d agree that this isn’t specifically an antipattern. It might be a smell depending upon the usage. There are reasons why one would actually not want to use exceptions (e.g. the errors being returned are not ‘exceptional’, for starters).

There are instances where you want to have a service return a common model for its results, including both errors and good values. This might be wrapped by a low level service interaction that translates the result into an exception or other error structure, but at the level of the service, it lets the service return a result and a status code without having to define some exception structure that might have to be translated across a remote boundary.

This code may not necessarily be an error either: consider an HTTP response, which consists of a lot of different data, including a status code, along with the body of the response.