Merge branch 'master' into feature/test-recorder

widget/src/column.rs

@@ -206,7 +206,7 @@ where
     }
 
     fn layout(
-        &self,
+        &mut self,
         tree: &mut Tree,
         renderer: &Renderer,
         limits: &layout::Limits,
@@ -222,13 +222,13 @@ where
             self.padding,
             self.spacing,
             self.align,
-            &self.children,
+            &mut self.children,
             &mut tree.children,
         )
     }
 
     fn operate(
-        &self,
+        &mut self,
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
@@ -237,12 +237,12 @@ where
         operation.container(None, layout.bounds());
         operation.traverse(&mut |operation| {
             self.children
-                .iter()
+                .iter_mut()
                 .zip(&mut tree.children)
                 .zip(layout.children())
                 .for_each(|((child, state), layout)| {
                     child
-                        .as_widget()
+                        .as_widget_mut()
                         .operate(state, layout, renderer, operation);
                 });
         });