QMetaObject crate for Rust VS Cargo

You can use Rust with QML[1].

QML is actually pretty amazing. I've been building my block editor[2] view entirely in QML while the model is in C++. This separation of logic and presentation works great. And yes, there are some crashes sometimes (that I find quite easy to debug thanks to the built-in debugger), but take for example a similar app that's built with Rust and Dart[3], in my testing there were still memory leaks that caused my computer to hang. It's better to know you have a bug than for it to be hidden from you.

I agree with parent commenter, saying these cross-platform frameworks will end up supporting the least common denominator set of features. But I found with external open source libraries, the community is catching up very fast. For example, you want the awesome translucency macOS apps have for your Qt app? Here you go[4]. Many such cases. It's also pretty straightforward to add your own custom OS-dependent code, especially so, if someone already open sourced his approach. I recently wanted to move the traffic light buttons on macOS for my app, but couldn't figure the Objective-C code for that. I ended up looking at either Tauri or Electron source code and found my answer.

[1] https://github.com/woboq/qmetaobject-rs

[2] https://www.get-plume.com/

[3] https://www.appflowy.io/

[4] https://github.com/stdware/qwindowkit

I just used qmetaobject-rs and my experience with Qt/QML. There's the QML book from Qt if you're just starting, which is pretty nice https://www.qt.io/product/qt6/qml-book

qmetaobject is probably the most mature Qt Rust binding at the moment. It uses the cpp crate to embed C++ inline in Rust to create its bindings. There are some people using it and it does get some maintenance, but it's not under active development since the original author is now working on Slint.

The bindings currently use the git version of qttypes since I had to merge some upstream changes that are needed for these bindings. So they are not ready for prime time just yet.

There are a bunch of bindings with different language, but even the ones that are officially supported like PySide will still be second class citizen and awkward to use.

Automated binding generation will never give you idiomatic API in whatever language. And if you want an idiomatic library that wraps Qt, it's going to take a huge amount of work.

Which is why I think restricting to QML makes sense because that's a much smaller API surface. That was the ambition behind my previous crate that exposes QML to rust: https://github.com/woboq/qmetaobject-rs/

But now I've moved on to another GUI project: Slint https://github.com/slint-ui/slint

Whisperfish does this with Qt: https://github.com/woboq/qmetaobject-rs/issues/102

What do you want to know? It's pretty easy thanks to the amazing work of guys behind qmetaobject-rs.

This is probably the portion that I found the most difficult. The README of qmetaobject-rs gives us a basic idea of the build script, so I started with that. Here is my starting script

Installing Trunk happens through Cargo. Remember, Cargo is more than a package manager, it also supports sub-commands.

Dependency Management in Other Languages: We've discussed Python and Node.js in this article, but dependency management is a universal concept in programming. Exploring how you handle dependencies in other languages like Java, C#, or Rust could be beneficial. (I think Rust's cargo is an excellent example of a package manager.)

Nice hack! Would it have been possible back then to use cargo to pull in some dependencies?

The clean solution of cargo script is here: https://github.com/rust-lang/cargo/issues/12207

Yes, I am sure this is going to be a part of Rust 1.77.0 and it will release on 21st March. I say that because of the tag in the PR (https://github.com/rust-lang/cargo/pull/13257#event-11505613...).

I'm no expert on Rust compiler development, but my understanding is that all code that is merged into master is available on nightly. If they're not behind a feature flag (this one isn't), they'll be available in a full release within 12 weeks of being merged. Larger features that need a lot more testing remain behind feature flags. Once they are merged into master, they remain on nightly until they're sufficiently tested. The multi-threaded frontend (https://blog.rust-lang.org/2023/11/09/parallel-rustc.html) is an example of such a feature. It'll remain nightly only for several months.

Again, I'm not an expert. This is based on what I've observed of Rust development.

The author provides very surface-level criticism of two Rust tools, but they don't look into why those choices were made.

With about five minutes of my time, I found out:

wrap_comments was introduced in 2019 [0]. There are bugs in the implementation (it breaks Markdown tables), so the option hasn't been marked as stable. Progress on the issue has been spotty.

--no-merge-sources is not trivial to re-implement [1]. The author has already explained why the flag no longer works -- Cargo integrated the command, but not all of the flags. This commit [2] explains why this functionality was removed in the first place.

Rust is open source, so the author of this blog post could improve the state of the software they care about by championing these issues. The --no-merge-sources error message even encourages you to open an issue, presumably so that the authors of Cargo can gauge the importance of certain flags/features.

You could even do something much simpler, like adding a comment to the related issues mentioning that you ran into these rough edges and that it made your life a little worse, or with a workaround that you found.

Alternatively, you can continue to write about how much free software sucks.

[0]: https://github.com/rust-lang/rustfmt/issues/3347

[1]: https://github.com/rust-lang/cargo/pull/10344

[2]: https://github.com/rust-lang/cargo/commit/3842d8e6f20067f716...

You try to use it as a part of multi-language project, with an external build tool to tie it all together, and you discover that --out-dir flag is still not stabilized over some future compatibility concerns.

To create a new application we'll use cargo (a build tool and also a package manager for Rust. It is used for scaffolding new library/binary projects). So in your projects folder, you can run this command in your terminal:

> ...but at the end of the day Cargo is the reason that Rust is popular.

FWIW, maybe that's true for you, but there are numerous other advantages to the language for which many people choose to use Rust--some even "despite" Cargo: you see Google having had to put in way way WAY too much work to get Bazel working for Rust :/--that it honestly feels a bit like belittling an extremely important language to make this claim so flippantly.

> You can set a default build target for a Cargo project with two lines of configuration, no nightly features necessary...

This doesn't work as, as soon as you start setting target-specific options, it infects the host build, as they incorrectly modelled the problem as some kind of map from targets to flags. If you don't believe me, on your Linux computer, try cross-compile something complicated that will runs on a "least common denominator" Linux distribution, such as CentOS 7.

> Can you clarify what this is referring to?

Sure. I've Googled rust cargo target host bugs for you (which, FWIW, finds a number of bugs I've filed or have talked about, but it isn't as if I have a list anywhere). Note that one of these bugs is "closed", but I still provide them for context as a patch might have been merged but (as you'll find out if you read through all of these) it isn't stable.

https://github.com/rust-lang/cargo/issues/8147

https://github.com/rust-lang/cargo/issues/3349

https://github.com/rust-lang/cargo/pull/9322

https://github.com/rust-lang/cargo/issues/9453

https://github.com/rust-lang/cargo/pull/9753

The result of this work being left incomplete is that increasingly large numbers of "serious" projects--things I'd expect people in packaging land to have heard of, such as BuildRoot--are being forced to set the ridiculous environment variable __CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS="nightly" in order to get access to a flag that makes Cargo sort of work.

(And yet, I often see people surprised at how long it is taking for various of the more important clients to fully get into using Rust, as the safety issues are so severe from continuing to use C/C++: as you made the contention that you believe the reason why people use Rust is Cargo, I will say the opposite: the reason why we don't see more Rust is also Cargo.)