devcodex · HackerTrans

vor 12 Jahrendiscuss

Thank you for taking the time to write this out, you hit the head exactly on what I was trying to accomplish with this article. I saw an opportunity to make a reusable tool for myself while at the same time being able to work on some of the best practices I've seen for developing library code. The real payoff is in the usage code.

Your simplification of the original code is great! I like how pulling out the creation of the the resource to its own line makes the typedef and unique_ptr initialization much easier to read (as far as templates go that is, a real sticking point here today).

I have updated my article and attributed the clarification to you, thanks again for your feedback and comments!

devcodex

vor 12 Jahrendiscuss

std::unique_ptr is a class that wraps around a pointer for the express purpose of providing RAII semantics. How is it not a wrapper class? All you're proposing is writing a class that does what unique_ptr does only now without templates each type has to be written out by hand.

Do you not ever make use of any of the STL templates like std::vector because their implementations are hard to read? Probably not, because they are easy to use and you never have to worry about how they are implemented. Well, here is how you use my function, please tell me how I could make this function call any easier because I honestly would like to know.

auto window = sdl2::create_window("New Window", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, 0);

I wrote a short function that I can reuse with any C based Init/Destroy created resource. Now that it works I never have to think about any of the template magic that went into writing it because using it is dead simple... there aren't even any angle brackets in the call. Not a single proposed "better" solution in this thread has shown the capability of creating resources in the general manner, each one shows the creation of a concrete class which means it has to be duplicated for each type. Which defeats the point of the article.

If you worked with templates back in the day then you probably aren't too familiar with the parameter pack syntax or auto return type deduction, these are new things and yes they are bleeding edge. How is anyone suppose to understand and learn good practices for using these features if they don't make use of them and write about it for others to provide feedback on?

I wrote this article to learn about specific techniques and get feedback on them. It's C++, there's a million ways to skin a cat here... and this article was specifically to address C++14 features. That's why it wasn't titled "C++03 and SDL". I thank you for taking the time to comment but telling someone they shouldn't make use of new compiler features because you aren't familiar with them and then not providing any sort of example yourself to the proposed problem doesn't come across as constructive at all.

devcodex

vor 12 Jahrendiscuss

The function that does all the work is 5 lines and then it works for any resource created from Init/Destroy function pair (a very common practice in C libraries), that's a hideous amount of code to you?

With your experience, how would you write a general solution for this problem?

devcodex

vor 12 Jahrendiscuss

Haha I wouldn't call myself a smart dev, just one that's trying to learn how to write good library code. If you really want to make your eyes bleed look at the proposed implementation of just such a utility:

http://isocpp.org/files/papers/N3949.pdf

Behind that wonderful STL code lies some crazy code behind the scenes. Is it beautiful? You won't catch me taking that argument! But is it typesafe with minimal overhead and easy for the end user of the code to understand and use? That's the one that's most important. For all the complexity of the template function itself, using it comes down to this:

    auto window = sdl2::make_window("App Name", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, 0);

Not an angle bracket in sight!

devcodex

vor 12 Jahrendiscuss

The code that makes use of templates and such is meant to be library code in the same way that STL is, not something the average user interacts with other than to know they need to pass an Init and Destroy function followed by initialization parameters. I don't see people tearing apart <tuple>'s code because of its complexity, or <vector> or any other reusable STL component that most developers who've complained about the verbosity of my solution use every day without batting an eye.

In these proposed solutions I've not yet seen one that has the capability to do this:

    auto window = make_resource(SDL_CreateWindow, SDL_DestroyWindow, ....);

With my solution all you have to do is call make resource with different parameters it automatically works with other C style init/destroy created resources, not just from the SDL library but any C library that follows that practice.

Can you try posting what your solution to the general problem would look like?

devcodex

vor 12 Jahrendiscuss

I definitely like the cleanliness of this solution but I'm still not sure how to work this into the general solution yet. The purpose was to take an opportunity to learn about how to implement reusable library code (as well as test drive a few C++14 features).

That said, I do like this approach and it gives me more to consider when approaching a problem like this again. I'm writing to learn so I welcome the constructive criticism.

devcodex

vor 12 Jahrendiscuss

Thanks for the comment and suggestion. How might this look in the general solution though? The type of the resource has to be deduced somewhere and I wasn't able to figure out a good way to deduce that and declare this style of deleter within the std namespace.

I'm all for eliminating that extra bit of overhead and don't claim to be an expert, the whole purpose for me writing this article was to specifically learn about how to write reusable library code. If you have any suggestions for how to pull this off in the general solution I'm all ears!

Thanks again for taking time to comment!