Work around issues with derive(Default)

src/widget/color_picker/mod.rs

@@ -122,7 +122,7 @@ impl<Message> ColorPickerModel<Message> {
         &self,
         f: T,
         icon_portion: Option<u16>,
-    ) -> crate::widget::Button<'a, Message, crate::Theme, crate::Renderer> {
+    ) -> crate::widget::Button<'a, Message, crate::Theme, crate::Renderer> where Message: 'static {
         color_button(
             Some(f(ColorPickerUpdate::ToggleColorPicker)),
             self.applied_color,

src/widget/segmented_button/model/builder.rs

@@ -8,9 +8,15 @@ use crate::widget::icon::Icon;
 use std::borrow::Cow;
 
 /// A builder for a [`Model`].
-#[derive(Default)]
 pub struct ModelBuilder<SelectionMode: Default, Message>(Model<SelectionMode, Message>);
 
+//TODO: Default derive ends up requiring Message to implement Default
+impl<SelectionMode: Default, Message> Default for ModelBuilder<SelectionMode, Message> {
+    fn default() -> Self {
+        Self(Model::default())
+    }
+}
+
 /// Constructs a new item for the [`ModelBuilder`].
 pub struct BuilderEntity<SelectionMode: Default, Message> {
     model: ModelBuilder<SelectionMode, Message>,

src/widget/segmented_button/model/mod.rs

@@ -53,7 +53,6 @@ pub type MultiSelectEntityMut<'a, Message> = EntityMut<'a, MultiSelect, Message>
 pub(super) struct Storage(HashMap<TypeId, SecondaryMap<Entity, Box<dyn Any>>>);
 
 /// The model held by the application, containing the unique IDs and data of each inserted item.
-#[derive(Default)]
 pub struct Model<SelectionMode: Default, Message> {
     /// The content used for drawing segmented items.
     pub(super) items: SlotMap<Entity, Settings>,
@@ -80,6 +79,22 @@ pub struct Model<SelectionMode: Default, Message> {
     pub(super) storage: Storage,
 }
 
+//TODO: Default derive ends up requiring Message to implement Default
+impl<SelectionMode: Default, Message> Default for Model<SelectionMode, Message> {
+    fn default() -> Self {
+        Self {
+            items: SlotMap::default(),
+            elements: SecondaryMap::default(),
+            icons: SecondaryMap::default(),
+            indents: SecondaryMap::default(),
+            text: SecondaryMap::default(),
+            order: VecDeque::default(),
+            selection: SelectionMode::default(),
+            storage: Storage::default(),
+        }
+    }
+}
+
 impl<SelectionMode: Default, Message> Model<SelectionMode, Message>
 where
     Self: Selectable,