bevy/crates/bevy_app/src/plugin.rs

use crate::App;
use std::any::Any;

/// A collection of Bevy App logic and configuration
///
/// Plugins configure an [App](crate::App). When an [App](crate::App) registers
/// a plugin, the plugin's [Plugin::build] function is run.
pub trait Plugin: Any + Send + Sync {
    fn build(&self, app: &mut App);
    fn name(&self) -> &str {
        std::any::type_name::<Self>()
    }
}

pub type CreatePlugin = unsafe fn() -> *mut dyn Plugin;