C++ Exceptions

I guess every C++ programmer out there have struggled with the question of whether or not to use exceptions. Some say they complicate the code, others that they are a serious performance hit.

I also gave it some time. After long hours of musing on the subject, coming up with examples - no matter how hard I tried to come up with a better solution for error handling, I always landed with something similar to exceptions.

You need some registration mechanism on entering a scope to get the best out of RAII. Also exceptions remove that obnoxious check and return pattern. Exceptions make you aware of the cost of a function call, so you are mildly pushed to rearrange your data and algorithms.

So my conclusion is: always use exceptions, just use them right. There is only one case for not using them, that is in real-time critical code (but you always have the option of redesigning algorithms to offset the cost of exceptions).

My personal checklist when using exceptions is this:

• any problem related to resources (network connection, files, memory etc.) should end with an exception
• any sort of bad input from outside world: wrong numbers, corrupted files, invalid input
• don't use exceptions for checking preconditions (use types and asserts for that)
• don't use exceptions for business logic
• combine exceptions with RAII for full throttle (take a look at Alexandrescu's scope_guard)
• don't confuse recovarable and irrecovarable ( covered by assertions ) cases

Exceptions are indispensable. There is just and odd anxiety among developers about them.