Minimal

I coded something the other day that got me thinking, primarily because I wasn’t satisfied with my solution. The dialog class in which I was working needed to make some changes to a couple of its controls. I added a new private method to make those changes and then coded away.

When done, I noticed I’d coded the same thing twice in the new method: once for each control. So, being a diligent refactorisor, I factored the duplication out to another private method and just called that for each control. Now, however, I had a private method that really shouldn’t be called from anywhere but another, specific private method.

This felt bad. I didn’t want other client code to mistakenly call the second method, as it logically belonged to the first method. At least, it did in my head. The second method’s existence only really made sense in the context of the first one. What to do? The following options fluttered into my head:

• Do nothing. Just live with it and get over it.
• Revert back to having the duplication — at least that would keep it hidden from client code.
• Explain the weirdness in the second method’s header comment.
• Make the second method into a nested method inside the first one. (D’oh! Turns out C++ doesn’t support nested functions.)
• Extract a class to do the control-fiddling that the two methods achieved and make the second method a private member of that class.
• Move the two methods into a new pair of CPP & H files, putting the first method into a namespace (exposing it in the header) and the second method into the implementation file only. This is essentially the same as the previous option, but without a class, so it sucks harder.
• Something else?

I read an article by Herb Sutter that converted the whole shebang into a functor, but it just looked too damn obscure. Anyone reading the resulting code would no doubt blurt a swift “WTF?”. Overkill, for sure.

In the end, I went with the second option above. Normally, I might’ve gone with the new class option, but in this case, I needed to avoid adding new files to the project (and that’s another story). I’m still not sure I did the right thing. What approach would you have taken?