rust-orphan-rules VS gdnative

Well, unless someone comes up with better, compatible rules, the orpan rules are gonna stick around.

Additionally there are other issues with rust currently. Compile time code (ala constexpr) is not up to par with C++20 (not really close). The const generic aren't as powerful as C++20 which added non primitive non type template parameters (though with you stuck with C++14, it actually is significantly better than what you have, again, if you're going to use C++, just use 20). Generics accepting closures is a bit more of an ordeal in rust, compared to C++. Also C++'s Duck Typed templates allow for some uncharacteristically strong typing compared to what is expressible in Rust generics currently. Now, duck typed templates do have major downsides, for example the entire feature of concepts is completely irrelevant in rust, but required for sane DTT type bounds, but they also have major upsides. Rust currently doesn't have "negative trait bounds", basically "This objected does not implement this trait, or std::enable_if> or the equivalent concepts implementation. Rust also doesn't have trait specializations, basically template specialization. Do note all features I've talked about to this point have nightly options, they just are at various stages of being stable/complete. Another issue is the orphan rule, though this is kind of a problem in C++ too in some respects, and that's unlikely to change drastically, since there are legitimate reasons for it's existence. For a lot of code none of these things are big deals, others they are, which is why you find inconsistent feed back on these issues.

Not that simple... hence why Orphan rule is still in-place. The struct wrapper was implemented in Rust as a temporary safe work-around. However, they are making progress on a solution: https://github.com/Ixrec/rust-orphan-rules/issues/1

That's still not an entirely complete explanation because there's more nuanced situations which aren't completely foreign but are foreign enough that if allowed, two crates could write the same impls. Some of the definitions are still unofficial as far as am I'm aware. For the best reference I’ve seen so far see this for more details.

In our crate the compiler doesn't know when calling MyTrait methods on MyStruct whether to use the implementation defined in crate 3 or crate 4! Rust has a set of orphan rules to prevent this situation from happening.

Sadly because of the rusts orphan rule you cannot implement a Trait on a Type where you do not own one or the other. So, apart from upstream contributions your only options are either a new Trait or a new Type.

If anyone is looking for additional background about orphan rules, check out https://github.com/Ixrec/rust-orphan-rules

It's a little less standard use, but Godot has been used to build application guis, which could be paired with rust bindings to implement app logic. I can't speak to reproducibility/scalability, but Godot's ui is extremely solid, and I'd probably choose that over Bevy until Bevy's ui progress matures.

Adding onto this, I successfully written a game in Godot using gdnative / gdext. I started with a split approach using gdscript and rust for CPU intensive but found that the API layer was slow at transferring large amounts of data (serialization?). I ended up rewriting it in all rust and it worked like a charm. I was able to target native and web assembly, the web assembly was much slower but worked on the browser.

Check this: https://github.com/tomuxmon/bevy_roguelike if you are still into bevy. Scheduling is a bit bork and I have not found time to port it to latest bevy. But most of the systems should work fine(if used on latest bevy). But again. If you want faster result go with something like Godot. In fact, just go with Godot. It is mature, easy to start, no lock in(free and MIT license), a lot of learning material. Also with Godot you can also use Rust https://godot-rust.github.io/. Ditch Unity (do not have time to explain 😅). Have fun!

Bevy Godot-Rust

> Same for Godot.

While likely true that it's "Unlikely to ever be as supported" as the 4 officially supported languages[0] ("GDScript, C#, and, via its GDExtension technology, C and C++."), Godot's GDExtension technology is specifically intended for use in adding support for other languages.

The most relevant tracking issue for Rust is presumably:

* <https://github.com/godot-rust/gdnative/issues/824>

Which links to:

* <https://github.com/godot-rust/gdextension>

[0] https://docs.godotengine.org/en/4.0/getting_started/step_by_...

...Godot v3.x has Rust support via godot-rust and Godot v4.0 is released as of this month?

I was curious, and looked it up. Nothing built in, but there's an interesting project that works with godot: https://godot-rust.github.io/

There's people working on it: https://godot-rust.github.io/