SCFrench SCFrench - 1 month ago 19
C++ Question

Does ScopeGuard use really lead to better code?

I came across this article written by Andrei Alexandrescu and Petru Marginean many years ago, which presents and discusses a utility class called ScopeGuard for writing exception-safe code. I'd like to know if coding with these objects truly leads to better code or if it obfuscates error handling, in that perhaps the guard's callback would be better presented in a catch block? Does anyone have any experience using these in actual production code?

Answer

It definitely improves your code. Your tentatively formulated claim, that it's obscure and that code would merit from a catch block is simply not true in C++ because RAII is an established idiom. Resource handling in C++ is done by resource acquisition and garbage collection is done by implicit destructor calls.

On the other hand, explicit catch blocks would bloat the code and introduce subtle errors because the code flow gets much more complex and resource handling has to be done explicitly.

RAII (including ScopeGuards) isn't an obscure technique in C++ but firmly established best-practice.