Item — HN Reader

> So some kids would complain that C++ destructors RAII philosophy require creating a whole "class X{public:~X()}" which is sometimes inconvenient so it doesn't exactly equal "finally".

Those figurative kids would be stuck in a mental model where they try to shoehorn their ${LanguageA} idioms onto applications written in ${LanguageB}. As the article says, C++ has destructors since the "C with Classes" days. Complaining that you might need to write a class is specious reasoning because if you have a resource worth managing, you already use RAII to manage it. And RAII is one of the most fundamental and defining features of C++.

It all boils down to whether one knows what they are doing, or even bothers to know what they are doing.

1 comments

Ok, but sometimes you just need a single line in a finally and writing a class is more annoying

> Ok, but sometimes you just need a single line in a finally and writing a class is more annoying

I don't think you understand.

If you need to run cleanup code whenever you need to destroy a resource, there is already a special member function designed to handle that: the destructor. Read up on RAII.

It somehow you failed to understand RAII and basic resource management, you can still use one-liners. Read up on scope guard.

If you are too lazy to learn about RAII and too lazy to implement a basic scope guard, you can use one of the many scope guard implementations around. Even Boost has those.

https://www.boost.org/doc/libs/latest/libs/scope/doc/html/sc...

So, unless you are lazy and want to keep mindlessly writing Java in ${LANGUAGE} regardless it makes sense or not, there is absolutely no reason at all to use finally in C++.

Slightly more than that: If you need to run cleanup code, whatever needs cleaned up should be a class and do the cleanup in the destructor.

Take a file handle, for instance. Don't use open() or fopen() and then try to close it in a finally. Instead, use a file class and let it close itself by going out of scope.