diff --git a/src/layout/widget.rs b/src/layout/widget.rs
index 9aec149..7f1eebb 100644
--- a/src/layout/widget.rs
+++ b/src/layout/widget.rs
@@ -70,10 +70,6 @@ macro_rules! WidgetFnRet {
 }
 pub(crate) use WidgetFnRet;
 
-pub trait _WidgetFn<W: Widget> {
-    fn call(ui: &mut Ui) -> W;
-}
-
 pub trait Idable {
     type Widget: Widget;
     fn set(self, ui: &mut Ui, id: &WidgetId<Self::Widget>);
diff --git a/src/util/id.rs b/src/util/id.rs
index cca6616..d5fd9ae 100644
--- a/src/util/id.rs
+++ b/src/util/id.rs
@@ -4,12 +4,12 @@
 /// point to something valid, although duplicate
 /// gets around this if needed
 #[derive(Eq, Hash, PartialEq, Debug)]
-pub struct ID(usize);
+pub struct ID(u64);
 
 #[derive(Default)]
 pub struct IDTracker {
     free: Vec<ID>,
-    cur: usize,
+    cur: u64,
 }
 
 impl IDTracker {