diff --git a/egui/src/containers/collapsing_header.rs b/egui/src/containers/collapsing_header.rs
index 117b7811..fd8e249b 100644
--- a/egui/src/containers/collapsing_header.rs
+++ b/egui/src/containers/collapsing_header.rs
@@ -347,10 +347,19 @@ impl CollapsingHeader {
         }
     }
 
+    #[inline]
     pub fn show<R>(
         self,
         ui: &mut Ui,
         add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> CollapsingResponse<R> {
+        self.show_dyn(ui, Box::new(add_contents))
+    }
+
+    fn show_dyn<'c, R>(
+        self,
+        ui: &mut Ui,
+        add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> CollapsingResponse<R> {
         // Make sure contents are bellow header,
         // and make sure it is one unit (necessary for putting a `CollapsingHeader` in a grid).
diff --git a/egui/src/containers/combo_box.rs b/egui/src/containers/combo_box.rs
index c088f251..5d171acc 100644
--- a/egui/src/containers/combo_box.rs
+++ b/egui/src/containers/combo_box.rs
@@ -69,6 +69,14 @@ impl ComboBox {
         self,
         ui: &mut Ui,
         menu_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<Option<R>> {
+        self.show_ui_dyn(ui, Box::new(menu_contents))
+    }
+
+    fn show_ui_dyn<'c, R>(
+        self,
+        ui: &mut Ui,
+        menu_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<Option<R>> {
         let Self {
             id_source,
@@ -83,7 +91,7 @@ impl ComboBox {
             if let Some(width) = width {
                 ui.spacing_mut().slider_width = width; // yes, this is ugly. Will remove later.
             }
-            let mut ir = combo_box(ui, button_id, selected_text, menu_contents);
+            let mut ir = combo_box_dyn(ui, button_id, selected_text, menu_contents);
             if let Some(label) = label {
                 ir.response
                     .widget_info(|| WidgetInfo::labeled(WidgetType::ComboBox, label.text()));
@@ -144,11 +152,11 @@ impl ComboBox {
 }
 
 #[allow(clippy::needless_pass_by_value)]
-fn combo_box<R>(
+fn combo_box_dyn<'c, R>(
     ui: &mut Ui,
     button_id: Id,
     selected: impl ToString,
-    menu_contents: impl FnOnce(&mut Ui) -> R,
+    menu_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
 ) -> InnerResponse<Option<R>> {
     let popup_id = button_id.with("popup");
 
diff --git a/egui/src/containers/frame.rs b/egui/src/containers/frame.rs
index a81710bc..c95ebe4f 100644
--- a/egui/src/containers/frame.rs
+++ b/egui/src/containers/frame.rs
@@ -155,6 +155,14 @@ impl Frame {
     }
 
     pub fn show<R>(self, ui: &mut Ui, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
+        self.show_dyn(ui, Box::new(add_contents))
+    }
+
+    fn show_dyn<'c, R>(
+        self,
+        ui: &mut Ui,
+        add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
+    ) -> InnerResponse<R> {
         let mut prepared = self.begin(ui);
         let ret = add_contents(&mut prepared.content_ui);
         let response = prepared.end(ui);
diff --git a/egui/src/containers/panel.rs b/egui/src/containers/panel.rs
index 47482083..6bf72de8 100644
--- a/egui/src/containers/panel.rs
+++ b/egui/src/containers/panel.rs
@@ -147,6 +147,15 @@ impl SidePanel {
         self,
         ui: &mut Ui,
         add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        self.show_inside_dyn(ui, Box::new(add_contents))
+    }
+
+    /// Show the panel inside a `Ui`.
+    fn show_inside_dyn<'c, R>(
+        self,
+        ui: &mut Ui,
+        add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<R> {
         let Self {
             side,
@@ -259,6 +268,15 @@ impl SidePanel {
         self,
         ctx: &CtxRef,
         add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        self.show_dyn(ctx, Box::new(add_contents))
+    }
+
+    /// Show the panel at the top level.
+    fn show_dyn<'c, R>(
+        self,
+        ctx: &CtxRef,
+        add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<R> {
         let layer_id = LayerId::background();
         let side = self.side;
@@ -266,7 +284,7 @@ impl SidePanel {
         let clip_rect = ctx.input().screen_rect();
         let mut panel_ui = Ui::new(ctx.clone(), layer_id, self.id, available_rect, clip_rect);
 
-        let inner_response = self.show_inside(&mut panel_ui, add_contents);
+        let inner_response = self.show_inside_dyn(&mut panel_ui, add_contents);
         let rect = inner_response.response.rect;
 
         match side {
@@ -406,6 +424,15 @@ impl TopBottomPanel {
         self,
         ui: &mut Ui,
         add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        self.show_inside_dyn(ui, Box::new(add_contents))
+    }
+
+    /// Show the panel inside a `Ui`.
+    fn show_inside_dyn<'c, R>(
+        self,
+        ui: &mut Ui,
+        add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<R> {
         let Self {
             side,
@@ -520,6 +547,15 @@ impl TopBottomPanel {
         self,
         ctx: &CtxRef,
         add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        self.show_dyn(ctx, Box::new(add_contents))
+    }
+
+    /// Show the panel at the top level.
+    fn show_dyn<'c, R>(
+        self,
+        ctx: &CtxRef,
+        add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<R> {
         let layer_id = LayerId::background();
         let available_rect = ctx.available_rect();
@@ -528,7 +564,7 @@ impl TopBottomPanel {
         let clip_rect = ctx.input().screen_rect();
         let mut panel_ui = Ui::new(ctx.clone(), layer_id, self.id, available_rect, clip_rect);
 
-        let inner_response = self.show_inside(&mut panel_ui, add_contents);
+        let inner_response = self.show_inside_dyn(&mut panel_ui, add_contents);
         let rect = inner_response.response.rect;
 
         match side {
@@ -585,6 +621,15 @@ impl CentralPanel {
         self,
         ui: &mut Ui,
         add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        self.show_inside_dyn(ui, Box::new(add_contents))
+    }
+
+    /// Show the panel inside a `Ui`.
+    fn show_inside_dyn<'c, R>(
+        self,
+        ui: &mut Ui,
+        add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<R> {
         let Self { frame } = self;
 
@@ -603,6 +648,15 @@ impl CentralPanel {
         self,
         ctx: &CtxRef,
         add_contents: impl FnOnce(&mut Ui) -> R,
+    ) -> InnerResponse<R> {
+        self.show_dyn(ctx, Box::new(add_contents))
+    }
+
+    /// Show the panel at the top level.
+    fn show_dyn<'c, R>(
+        self,
+        ctx: &CtxRef,
+        add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<R> {
         let available_rect = ctx.available_rect();
         let layer_id = LayerId::background();
@@ -611,7 +665,7 @@ impl CentralPanel {
         let clip_rect = ctx.input().screen_rect();
         let mut panel_ui = Ui::new(ctx.clone(), layer_id, id, available_rect, clip_rect);
 
-        let inner_response = self.show_inside(&mut panel_ui, add_contents);
+        let inner_response = self.show_inside_dyn(&mut panel_ui, add_contents);
 
         // Only inform ctx about what we actually used, so we can shrink the native window to fit.
         ctx.frame_state()
diff --git a/egui/src/containers/popup.rs b/egui/src/containers/popup.rs
index 54b5f25c..db03aad6 100644
--- a/egui/src/containers/popup.rs
+++ b/egui/src/containers/popup.rs
@@ -100,12 +100,12 @@ pub fn show_tooltip_under<R>(
     add_contents: impl FnOnce(&mut Ui) -> R,
 ) -> Option<R> {
     let expanded_rect = rect.expand2(vec2(2.0, 4.0));
-    show_tooltip_at_avoid(
+    show_tooltip_at_avoid_dyn(
         ctx,
         id,
         Some(expanded_rect.left_bottom()),
         expanded_rect,
-        add_contents,
+        Box::new(add_contents),
     )
 }
 
@@ -118,15 +118,21 @@ pub fn show_tooltip_at<R>(
     suggested_position: Option<Pos2>,
     add_contents: impl FnOnce(&mut Ui) -> R,
 ) -> Option<R> {
-    show_tooltip_at_avoid(ctx, id, suggested_position, Rect::NOTHING, add_contents)
+    show_tooltip_at_avoid_dyn(
+        ctx,
+        id,
+        suggested_position,
+        Rect::NOTHING,
+        Box::new(add_contents),
+    )
 }
 
-fn show_tooltip_at_avoid<R>(
+fn show_tooltip_at_avoid_dyn<'c, R>(
     ctx: &CtxRef,
     mut id: Id,
     suggested_position: Option<Pos2>,
     mut avoid_rect: Rect,
-    add_contents: impl FnOnce(&mut Ui) -> R,
+    add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
 ) -> Option<R> {
     let mut tooltip_rect = Rect::NOTHING;
     let mut count = 0;
@@ -170,7 +176,7 @@ fn show_tooltip_at_avoid<R>(
 
     let position = position.max(ctx.input().screen_rect().left_top());
 
-    let InnerResponse { inner, response } = show_tooltip_area(ctx, id, position, add_contents);
+    let InnerResponse { inner, response } = show_tooltip_area_dyn(ctx, id, position, add_contents);
     ctx.memory()
         .data_temp
         .get_mut_or_default::<crate::containers::popup::MonoState>()
@@ -201,11 +207,11 @@ pub fn show_tooltip_text(ctx: &CtxRef, id: Id, text: impl ToString) -> Option<()
 }
 
 /// Show a pop-over window.
-fn show_tooltip_area<R>(
+fn show_tooltip_area_dyn<'c, R>(
     ctx: &CtxRef,
     id: Id,
     window_pos: Pos2,
-    add_contents: impl FnOnce(&mut Ui) -> R,
+    add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
 ) -> InnerResponse<R> {
     use containers::*;
     Area::new(id)
diff --git a/egui/src/containers/scroll_area.rs b/egui/src/containers/scroll_area.rs
index a74f8c5b..a4dfdfbd 100644
--- a/egui/src/containers/scroll_area.rs
+++ b/egui/src/containers/scroll_area.rs
@@ -304,7 +304,7 @@ impl ScrollArea {
     ///
     /// If the inner area can be very long, consider using [`Self::show_rows`] instead.
     pub fn show<R>(self, ui: &mut Ui, add_contents: impl FnOnce(&mut Ui) -> R) -> R {
-        self.show_viewport(ui, |ui, _viewport| add_contents(ui))
+        self.show_viewport_dyn(ui, Box::new(|ui, _viewport| add_contents(ui)))
     }
 
     /// Efficiently show only the visible part of a large number of rows.
@@ -357,6 +357,14 @@ impl ScrollArea {
     /// `add_contents` is past the viewport, which is the relative view of the content.
     /// So if the passed rect has min = zero, then show the top left content (the user has not scrolled).
     pub fn show_viewport<R>(self, ui: &mut Ui, add_contents: impl FnOnce(&mut Ui, Rect) -> R) -> R {
+        self.show_viewport_dyn(ui, Box::new(add_contents))
+    }
+
+    fn show_viewport_dyn<'c, R>(
+        self,
+        ui: &mut Ui,
+        add_contents: Box<dyn FnOnce(&mut Ui, Rect) -> R + 'c>,
+    ) -> R {
         let mut prepared = self.begin(ui);
         let ret = add_contents(&mut prepared.content_ui, prepared.viewport);
         prepared.end(ui);
diff --git a/egui/src/containers/window.rs b/egui/src/containers/window.rs
index e9fa1e80..7468eae0 100644
--- a/egui/src/containers/window.rs
+++ b/egui/src/containers/window.rs
@@ -240,15 +240,16 @@ impl<'open> Window<'open> {
 impl<'open> Window<'open> {
     /// Returns `None` if the window is not open (if [`Window::open`] was called with `&mut false`).
     /// Returns `Some(InnerResponse { inner: None })` if the window is collapsed.
+    #[inline]
     pub fn show<R>(
         self,
         ctx: &CtxRef,
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> Option<InnerResponse<Option<R>>> {
-        self.show_impl(ctx, Box::new(add_contents))
+        self.show_dyn(ctx, Box::new(add_contents))
     }
 
-    fn show_impl<'c, R>(
+    fn show_dyn<'c, R>(
         self,
         ctx: &CtxRef,
         add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
diff --git a/egui/src/grid.rs b/egui/src/grid.rs
index 1b1c5896..b8489f04 100644
--- a/egui/src/grid.rs
+++ b/egui/src/grid.rs
@@ -328,6 +328,14 @@ impl Grid {
 
 impl Grid {
     pub fn show<R>(self, ui: &mut Ui, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
+        self.show_dyn(ui, Box::new(add_contents))
+    }
+
+    fn show_dyn<'c, R>(
+        self,
+        ui: &mut Ui,
+        add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
+    ) -> InnerResponse<R> {
         let Self {
             id_source,
             num_columns,
diff --git a/egui/src/response.rs b/egui/src/response.rs
index 65fdd28a..c181626c 100644
--- a/egui/src/response.rs
+++ b/egui/src/response.rs
@@ -552,6 +552,7 @@ pub struct InnerResponse<R> {
 }
 
 impl<R> InnerResponse<R> {
+    #[inline]
     pub fn new(inner: R, response: Response) -> Self {
         Self { inner, response }
     }
diff --git a/egui/src/ui.rs b/egui/src/ui.rs
index d8fefb88..1de9032e 100644
--- a/egui/src/ui.rs
+++ b/egui/src/ui.rs
@@ -1279,6 +1279,13 @@ impl Ui {
     /// });
     /// ```
     pub fn scope<R>(&mut self, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
+        self.scope_dyn(Box::new(add_contents))
+    }
+
+    fn scope_dyn<'c, R>(
+        &mut self,
+        add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
+    ) -> InnerResponse<R> {
         let child_rect = self.available_rect_before_wrap();
         let next_auto_id_source = self.next_auto_id_source;
         let mut child_ui = self.child_ui(child_rect, *self.layout());
@@ -1391,13 +1398,12 @@ impl Ui {
     /// ```
     ///
     /// See also [`Self::with_layout`] for more options.
-    #[inline(always)]
+    #[inline]
     pub fn horizontal<R>(&mut self, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
-        self.horizontal_with_main_wrap(false, add_contents)
+        self.horizontal_with_main_wrap_dyn(false, Box::new(add_contents))
     }
 
     /// Like [`Self::horizontal`], but aligns content with top.
-    #[inline(always)]
     pub fn horizontal_top<R>(
         &mut self,
         add_contents: impl FnOnce(&mut Ui) -> R,
@@ -1431,16 +1437,7 @@ impl Ui {
         &mut self,
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> InnerResponse<R> {
-        self.horizontal_with_main_wrap(true, add_contents)
-    }
-
-    #[inline(always)]
-    fn horizontal_with_main_wrap<R>(
-        &mut self,
-        main_wrap: bool,
-        add_contents: impl FnOnce(&mut Ui) -> R,
-    ) -> InnerResponse<R> {
-        self.horizontal_with_main_wrap_dyn(main_wrap, Box::new(add_contents))
+        self.horizontal_with_main_wrap_dyn(true, Box::new(add_contents))
     }
 
     fn horizontal_with_main_wrap_dyn<'c, R>(
@@ -1477,7 +1474,7 @@ impl Ui {
     /// See also [`Self::with_layout`] for more options.
     #[inline(always)]
     pub fn vertical<R>(&mut self, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
-        self.with_layout(Layout::top_down(Align::Min), add_contents)
+        self.with_layout_dyn(Layout::top_down(Align::Min), Box::new(add_contents))
     }
 
     /// Start a ui with vertical layout.
@@ -1490,11 +1487,12 @@ impl Ui {
     ///     ui.label("under");
     /// });
     /// ```
+    #[inline]
     pub fn vertical_centered<R>(
         &mut self,
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> InnerResponse<R> {
-        self.with_layout(Layout::top_down(Align::Center), add_contents)
+        self.with_layout_dyn(Layout::top_down(Align::Center), Box::new(add_contents))
     }
 
     /// Start a ui with vertical layout.
@@ -1511,9 +1509,9 @@ impl Ui {
         &mut self,
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> InnerResponse<R> {
-        self.with_layout(
+        self.with_layout_dyn(
             Layout::top_down(Align::Center).with_cross_justify(true),
-            add_contents,
+            Box::new(add_contents),
         )
     }
 
@@ -1529,6 +1527,7 @@ impl Ui {
     ///
     /// See also [`Self::allocate_ui_with_layout`],
     /// and the helpers [`Self::horizontal]`, [`Self::vertical`], etc.
+    #[inline]
     pub fn with_layout<R>(
         &mut self,
         layout: Layout,
@@ -1562,9 +1561,9 @@ impl Ui {
         &mut self,
         add_contents: impl FnOnce(&mut Self) -> R,
     ) -> InnerResponse<R> {
-        self.with_layout(
+        self.with_layout_dyn(
             Layout::centered_and_justified(Direction::TopDown),
-            add_contents,
+            Box::new(add_contents),
         )
     }
 
@@ -1605,10 +1604,20 @@ impl Ui {
     ///     columns[1].label("Second column");
     /// });
     /// ```
-    pub fn columns<F, R>(&mut self, num_columns: usize, add_contents: F) -> R
-    where
-        F: FnOnce(&mut [Self]) -> R,
-    {
+    #[inline]
+    pub fn columns<R>(
+        &mut self,
+        num_columns: usize,
+        add_contents: impl FnOnce(&mut [Self]) -> R,
+    ) -> R {
+        self.columns_dyn(num_columns, Box::new(add_contents))
+    }
+
+    fn columns_dyn<'c, R>(
+        &mut self,
+        num_columns: usize,
+        add_contents: Box<dyn FnOnce(&mut [Self]) -> R + 'c>,
+    ) -> R {
         // TODO: ensure there is space
         let spacing = self.spacing().item_spacing.x;
         let total_spacing = spacing * (num_columns as f32 - 1.0);
diff --git a/sh/find_bloat.sh b/sh/find_bloat.sh
index 813e35fd..f77f8d84 100755
--- a/sh/find_bloat.sh
+++ b/sh/find_bloat.sh
@@ -4,3 +4,5 @@ script_path=$( cd "$(dirname "${BASH_SOURCE[0]}")" ; pwd -P )
 cd "$script_path/.."
 
 cargo bloat --release --bin egui_demo_app -n 200 | rg "egui "
+
+cargo llvm-lines -p egui_demo_lib | rg egui | head -30