Allow Overlay::overlay to borrow Layout

core/src/overlay.rs

@@ -82,7 +82,7 @@ where
     /// Returns the nested overlay of the [`Overlay`], if there is any.
     fn overlay<'a>(
         &'a mut self,
-        _layout: Layout<'_>,
+        _layout: Layout<'a>,
         _renderer: &Renderer,
     ) -> Option<Element<'a, Message, Theme, Renderer>> {
         None

core/src/overlay/element.rs

@@ -130,7 +130,7 @@ where
 
     fn overlay<'a>(
         &'a mut self,
-        layout: Layout<'_>,
+        layout: Layout<'a>,
         renderer: &Renderer,
     ) -> Option<Element<'a, B, Theme, Renderer>> {
         self.content

core/src/overlay/group.rs

@@ -138,7 +138,7 @@ where
 
     fn overlay<'a>(
         &'a mut self,
-        layout: Layout<'_>,
+        layout: Layout<'a>,
         renderer: &Renderer,
     ) -> Option<overlay::Element<'a, Message, Theme, Renderer>> {
         let children = self

runtime/src/overlay/nested.rs

@@ -42,12 +42,15 @@ where
             let overlay = element.as_overlay_mut();
             let node = overlay.layout(renderer, bounds);
 
-            if let Some(mut nested) =
+            let nested_node = overlay
-                overlay.overlay(Layout::new(&node), renderer)
+                .overlay(Layout::new(&node), renderer)
-            {
+                .as_mut()
+                .map(|nested| recurse(nested, renderer, bounds));
+
+            if let Some(nested_node) = nested_node {
                 layout::Node::with_children(
                     node.size(),
-                    vec![node, recurse(&mut nested, renderer, bounds)],
+                    vec![node, nested_node],
                 )
             } else {
                 layout::Node::with_children(node.size(), vec![node])

widget/src/themer.rs

@@ -257,7 +257,7 @@ where
 
             fn overlay<'b>(
                 &'b mut self,
-                layout: Layout<'_>,
+                layout: Layout<'b>,
                 renderer: &Renderer,
             ) -> Option<overlay::Element<'b, Message, Theme, Renderer>>
             {