Bevy Discovery

This crate adds #[derive(DiscoveryPlugin)] which will scan the project files for functions annotated with #[system] and register them automagically. Example:

use bevy::prelude::*;

#[macro_use]
extern crate bevy_discovery;

fn main() {
    App::build()
        .add_plugin(DiscoveryPlugin)
        .run();
}

#[system]
fn discovered_system() {
    println!("Woo, discovered system!");
}

#[system(stage::POST_UPDATE)]
fn post_update_system() {
    println!("Hey, post update system!");
}

#[derive(DiscoveryPlugin)]
struct DiscoveryPlugin;

Compile time performance

These are the compile times for my fork of bevy-robbo, averaged over five runs with a discarded warmup round each using hyperfine.