cross-posted from: https://vger.social/post/19509421

godot-rust v0.3 brings type-safe signals to the table.
If you register a signal:

#[signal]
fn damage_taken(amount: i32);

you can now freely connect it with other Rust functions:

fn ready(&mut self) {
    // Connect signal to the method:
    self.signals().damage_taken().connect(Self::on_damage_taken);
    
    // Or to an ad-hoc closure:
    self.signals().damage_taken().connect(|amount| {
        println!("Damage taken: {}", amount);
    });
    
    // Or to a method of another object:
    let stats: Gd<Stats>;
    self.signals().damage_taken().connect_other(&stats, |stats, amount| {
        stats.update_total_damage(amount);
    });
}

Emitting is also type-safe:

self.signals().damage_taken().emit(42);

Furthermore, you can now await signals, effectively introducing async tasks:

godot::task::spawn(async move {
    godot_print!("Wait for damage to occur...");
    
    let (dmg,) = player.signals().damage_taken().to_future().await;
    godot_print!("Player took {dmg} damage.");
});

There are many other improvements, see devlog and feel free to ask me anything :)

Huge thanks to all the contributors who helped ship these features!

~this was originally posted by @[email protected] the project author on reddit. I’m just maintaining some parts of the project.~