refactor: collect collections

crates/tek_core/src/engine/component.rs

@@ -5,3 +5,13 @@ pub trait Component<E: Engine>: Render<E> + Handle<E> {}
 
 /// Everything that implements [Render] and [Handle] is a [Component].
 impl<E: Engine, C: Render<E> + Handle<E>> Component<E> for C {}
+
+/// Marker trait for [Component]s that can [Exit]
+pub trait ExitableComponent<E>: Exit + Component<E> where E: Engine {
+    /// Perform type erasure for collecting heterogeneous components.
+    fn boxed (self) -> Box<dyn ExitableComponent<E>> where Self: Sized + 'static {
+        Box::new(self)
+    }
+}
+
+impl<E: Engine, C: Component<E> + Exit> ExitableComponent<E> for C {}