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Comment by lifthrasiir | Hacker News Reader

You completely ignored dependencies, which in my experience everyone seems to handle differently (and definitely not in a declarative way).

Differently put: a phrase "metabuild system" has both a lexical sense and an idealized sense. The lexical sense would be something that generates an input to build systems. The idealized sense would be something that does everything else not possible or difficult in build systems. CMake was definitely far from that ideal [1]; it was often simpler to make a configure script in your favorite language (and, for god's sake, not in M4) than using CMake.

[1] Was using a present tense but edited after realizing that I don't know much about recent changes to CMake. Still enough to justify my (and others') criticism.

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> You completely ignored dependencies

Not really. When people talk about setting up a new project, they talk about starting a hello world project and build up from there.

Anyway, I'll bite. What would it take to add a dependency? If it exports a cmake config file which exports targets, all it takes is this:

find_package(MyDependency),

target_link_libraries(bar MyDependency::targetA MyDependency::targetB ... MyDependency::targetZ )

If it doesn't and it is instead a system library then you can even pass the library instead.

add_library(bar systemlibrary )

If the library exports no cmake config and you have anything exotic you can put together your own cmake find modules, and proceed to follow step A.

Alternatively, you can even bolt on something like Conan and just follow step A all the time.

> Differently put: a phrase "metabuild system" has (...)

Sorry, but do you actually have any concrete example of any difficulty setting up a C++ project?

> When people talk about setting up a new project, they talk about starting a hello world project and build up from there.

The original reply said one dabbled C++ via "creative coding, graphics programming, etc.", which definitely needs dependencies from the beginning. Can you draw a nicely shaded triangle only with the C++ standard library?

> If the library exports no cmake config and you have anything exotic you can put together your own cmake find modules, and proceed to follow step A.

They are not exotic, libraries without cmake config are common. So, as I've said before, people had to come up with their own find modules and this requires lots of trial and error to get it right. Guaranteed, it might have been possible to collect those into some sort of registry (a la DefinitelyTyped for TypeScript .d.ts files), and probably something like Conan can provide that, but ideally that should have been built into CMake. And keep in mind that Cargo---something we were comparing against back in time---does all of them declaratively. (Arguably, from users' perspective, it can handle C/C++ dependencies better than CMake!)

> The original reply said one dabbled C++ via "creative coding, graphics programming, etc.", which definitely needs dependencies from the beginning. Can you draw a nicely shaded triangle only with the C++ standard library?

Taken straight from Qt's page on OpenGL support:

find_package(Qt6 REQUIRED COMPONENTS OpenGL) target_link_libraries(mytarget PRIVATE Qt6::OpenGL)

https://doc.qt.io/qt-6/qtopengl-index.html

Do you feel this is too hard to setup?

That's because Qt 6 wholeheartedly converted to CMake for you. (At least it is better than qmake.) In order to support this Qt has this large battery of CMake files [1]. Qt is of course a clear outlier, but you can't expect the same level of support from every other library you want. My points about "anything exotic" still stand.

[1] https://github.com/qt/qtbase/tree/dev/cmake

> That's because Qt 6 wholeheartedly converted to CMake for you.

It's not Qt6. The same goes for Qt5, which has been around for what, close to a decade?

And what's your point, exactly? That things are hard if you purposedly ignore all the examples that prove that things are patently easy and trivial? Because it seems evident to me that if you want to quickly setup a C++ project to try out stuff, a CMake project with single-digit lines of code that get you a window with an OpenGL context going is right what you'd be looking for.

But instead you complain that the choice of build system and framework made things easy? And that's why things are not hard

What exactly do you think is your point?

Yes! I spent 2 hours the other day trying to figure out why some OpenGL header had moved in between macOS versions, or had failed to install correctly with Xcode. OpenGL is indeed, not an exotic library, but this is the perfect example of why working on these projects is annoying. It's totally platform dependent, and while people who spend most of their time in C/C++ land are used to hunting down system libraries, "where does this random file that got installed with unrelated platform toolchain get installed" is painful.

I have no doubt that people who work on big commercial C++ project have sensible build systems and documentation that's not too hard. But it's incredibly common when working in this art/graphics space to need to try to get someone's bitrotted random project without docs or build system running. Common to have to do that AND have to do it on another platform.

OpenGL is particularly strange because the libraries can be provided by the graphics card vendor.

That said... Rust and OpenGL have quite an impedance mismatch, don't they?

There totally is an impedance mismatch. It's definitely not as bad as you might think, but this is exactly the reason that I theoretically want to use C++. Art code is the perfect example of code where (a). mutability is whatever / good and (b). safety literally does not matter. Its the ultimate domain of hacking something together to make something pretty on the screen, not serious software engineering.

In Rust, using a library is as simple as “cargo add library”, and this is always the case. It’s even the case for most popular C/C++ libraries which tend to have Rust wrappers available that seamlessly integrate them with cargo.

In modern C++ if one isn't using either vcpkg nor conan, they shouldn't complain about having an hard time to find libraries.

The options are there to be used.

> do you actually have any concrete example of any difficulty setting up a C++ project?

Take a look: https://stackoverflow.com/questions/75270938/thread-pool-wit...

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