iced-counter2 VS druid

The iced package requires the messages to implement the Debug, Clone, and Send traits, none of which are available for closures. I was able to implement something similar to your example[0] but it only supports plain function pointers for the callbacks. The compiler wasn't able to derive a sufficiently general Debug trait for the function pointer due to an issue with the lifetime of the argument, so I had to implement that myself as well.

Incidentally, as long as there are situations where only function pointers can be used and not closures it would be really nice to have some support for anonymous function pointers in Rust (with the fn type and not just the Fn trait) so that one could write e.g. "Message(fn |c| c.value += 1)" instead of "Message({ fn f(c: &mut Counter) { c.value += 1 } f })". Or just infer the fn type for "closures" which don't actually close over any variables without the need for an extra keyword.

[0] https://github.com/nybble41/iced-counter2/blob/master/src/ma...

For GUI applications, the story is mixed. There are several GUI frameworks in active development, but nothing as polished and battle-tested as Electron for TypeScript. There are bindings to GTK, but they're cumbersome to work with, and I wouldn't recommend it to a Rust newbie. There's also Tauri, which is a bit like Electron and lets you write the GUI in HTML/CSS/JS and the business logic in Rust.

Concerning GUI frameworks, the most common ones are druid, egui and iced. All three of them run native and on the Web.

Going to give a shoutout to druid. I've recently tried it with the Lapce editor and it's just so smooth, fast and works so well for a pre-alpha app.

As iced and egui were difficult for me, i started with druid.

There is Iced which is used by system76 in Pop!_OS, Druid [DISCONTINUED], GTK-rs, Relm, Azul and Tauri. Personally I would use Tauri for its speed using the OS's native web render, documentation of use with things such as Sveltekit and the ability to make UI's using JS, CSS and HTML. Tauri similarly to Electron whilst being far faster. But its up to personal preference really. There aren't any solid "go to" options at the moment.

Druid should be good for most cases, it has a lot of built-in widget for the UI, you can even make a custom widget with a canvas-alike painting API.

Druid, which is a Rust-native UI toolkit for building desktop applications targeting Windows/macOS/Linux/OpenBSD/FreeBSD, has a new version out - v0.8.

There's a memoize View node in the previous iteration of the Xilem prototype, but it hasn't made it in to the current branch yet. That sounds like what you're asking, but it's possible I'm missing something.

You can use GTK from Rust. But the Rust native ones aren't really there yet. [Iced](https://github.com/iced-rs/iced) which has been picked up by System76 and [Druid](https://github.com/linebender/druid) (and it's next gen version [Xilem](https://github.com/linebender/xilem)) are the ones to watch, along with Dioxus which is the main post here.

I'd expect there to be something useable by the end of 2023.