crubit VS verdigris

See also:

Thomas Neumann's current proposal for memory safe C++ using dependency tracking:

- https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p27...

Google's proposal for memory safety using Rust-like lifetime analysis:

- https://discourse.llvm.org/t/rfc-lifetime-annotations-for-c/...

- https://github.com/google/crubit/tree/main/lifetime_analysis

For the people who are curious: crubit is an attempt to develop the way to seamlessly integrate C++ and Rust.

Please see the experimentation and proposals at https://github.com/google/crubit/blob/main/docs/lifetime_annotations_cpp.md and https://github.com/google/crubit/blob/main/docs/lifetimes_static_analysis.md

autocxx is good, though crubit is aiming for direct bidirectional interop

The areas you mentioned (CLI, web services, low level systems programming) are not mutually exclusive. Doing a good job on one doesn't mean something else is affected.

The folks who worked on the most popular command line argument parser (https://docs.rs/clap/latest/clap/#example) made a positive contribution that didn't detract from any other use case.

Similarly, the folks working on improving Rust for web services will also make it better for systems programming. In a blog post published today (https://blog.rust-lang.org/inside-rust/2022/07/27/keyword-ge...), they discuss keyword generics, a feature that will be equally helpful for `async` code and `const` functions evaluated at compile time.

There is already some interoperability with C++ (http://cxx.rs) and ongoing research into automating this interoperability (https://github.com/google/autocxx, https://github.com/google/crubit). Feels like there's enough effort

This language was started by folks at Google. (Although it's interesting that they're publishing it under a separate github org, which suggests ambitions beyond Google's needs.) Google has a huge, performance-sensitive C++ codebase. At Google, major product teams' backends are typically written in C++, as well as common infrastructure like D (disk server), Colossus (distributed filesystem), Spanner (distributed SQL database), and Borg (cluster management). More than a few people would love for it all to be be written in Rust instead, but migration would be challenging, to say the least. I'm told people are looking into it—see Crubit for example. But AFAIK, no one's decided yet whether Google will stay with C++ for all these things, migrate some to Rust, migrate some to Carbon, and/or do something else entirely.

It's currently unclear if Rust can interop with C++ with high fidelity. For example https://docs.rs/moveit/latest/moveit/ and https://github.com/google/crubit/blob/main/rs_bindings_from_... provide functionality to use non-trivially relocatable C++ types from Rust.

This is overly dramatic. The "keywords" are just macros. If you don't want an additional preprocessor to generate code in a separate .cpp file from these macros, you can use https://github.com/woboq/verdigris

The concurrency model, object ownership and life cycle you are mentioning are not part of C++, those are just conventions in specific C++ user groups - Qt code compiles plain and simple with pretty much every conformant C++ compiler and that makes it as much C++ as anything else.

There were a couple of attempts in that direction, but i haven't really seen them used in any production codebase.

https://woboq.com/blog/verdigris-qt-without-moc.html

Is Moc for signals and slots still needed? Mind you, I haven't used Qt in 15 years, but I was sure I heard about some standard C++ way of building Qt apps without needing the MOC prebuild step (IIRC https://woboq.com/blog/verdigris-qt-without-moc.html).

Nope, Qt 6 still uses moc. I don't think modern C++ meta programming is quite capable of entirely replacing moc. The closest thing I'm aware of is [0], but it requires additional macros compared to what moc requires, and compilation speed can suffer. Chances are moc won't be dropped until full reflection lands, if ever, and even then if compilation speed is too bad I wouldn't be entirely surprised if moc remains.

[0]: https://github.com/woboq/verdigris

Verdigris

`QML_ELEMENT` support for Verdigris. https://github.com/woboq/verdigris/pull/99

> it's possible to do Qt without moc even in C++ with https://github.com/woboq/verdigris/, why wouldn't it be possible from D ?

You're talking about an entirely different thing. While OP was referring to the current state of D's ecosystem and the impact that missing key frameworks have on hindering adoption, you're arguing about the theoretical possibility of writing a framework with a language, which really does not address OP's point.

And much more importantly, MOC specifically is a code generator which has a competitor without the code generation requirement. Fully compatible even. So no, sorry "Qt is bad because MOC" stopped being an argument years ago (if it ever was).

But copperspice is not a better version: see the benchmark here: https://woboq.com/blog/verdigris-qt-without-moc.html