From 9c600cb3cede8bb439186c879da8ce229efac125 Mon Sep 17 00:00:00 2001
From: Padraic Fanning <fanninpm@miamioh.edu>
Date: Fri, 30 Apr 2021 14:45:03 -0400
Subject: [PATCH] Add 84727

Issue: rust-lang/rust#84727
---
 ices/84727.rs | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 ices/84727.rs

diff --git a/ices/84727.rs b/ices/84727.rs
new file mode 100644
index 00000000..865d0b03
--- /dev/null
+++ b/ices/84727.rs
@@ -0,0 +1,55 @@
+pub struct Color<T>(pub T);
+
+pub struct Cell<Fg, Bg = Fg> {
+    foreground: Color<Fg>,
+    background: Color<Bg>,
+}
+
+pub trait Over<Bottom, Output> {
+    fn over(self, bottom: Bottom) -> Output;
+}
+
+// Cell: Over<Color, Cell>
+impl<C, Fg, Bg, NewFg, NewBg> Over<Color<C>, Cell<NewFg, NewBg>> for Cell<Fg, Bg>
+where
+    Fg: Over<C, NewFg>,
+    Bg: Over<C, NewBg>,
+{
+    fn over(self, _: Color<C>) -> Cell<NewFg, NewBg> {
+        todo!();
+    }
+}
+
+// Cell: Over<Cell, Cell>
+impl<TopFg, TopBg, BottomFg, BottomBg, NewFg, NewBg>
+    Over<Cell<BottomFg, BottomBg>, Cell<NewFg, NewBg>> for Cell<TopFg, TopBg>
+where
+    Self: Over<Color<BottomBg>, Cell<NewFg, NewBg>>,
+{
+    fn over(self, bottom: Cell<BottomFg, BottomBg>) -> Cell<NewFg, NewBg> {
+        self.over(bottom.background);
+        todo!();
+    }
+}
+
+// Cell: Over<&mut Cell, ()>
+impl<'b, TopFg, TopBg, BottomFg, BottomBg> Over<&'b mut Cell<BottomFg, BottomBg>, ()>
+    for Cell<TopFg, TopBg>
+where
+    Cell<TopFg, TopBg>: Over<Cell<BottomFg, BottomBg>, Cell<BottomFg, BottomBg>>,
+{
+    fn over(self, _: &'b mut Cell<BottomFg, BottomBg>) {
+        todo!();
+    }
+}
+
+// &Cell: Over<&mut Cell, ()>
+impl<'t, 'b, TopFg, TopBg, BottomFg, BottomBg> Over<&'b mut Cell<BottomFg, BottomBg>, ()>
+    for &'t Cell<TopFg, TopBg>
+where
+    Cell<TopFg, TopBg>: Over<Cell<BottomFg, BottomBg>, Cell<BottomFg, BottomBg>>,
+{
+    fn over(self, _: &'b mut Cell<BottomFg, BottomBg>) {
+        todo!();
+    }
+}