Add 80231

Issue: rust-lang/rust#80231

ices/80231.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+rustc -Zchalk - <<'EOF'
+use std::ops::Add;
+
+pub trait Encoder {
+	type Size: Add<Output = Self::Size>;
+
+	fn foo(&self) -> Self::Size;
+}
+
+pub trait SubEncoder : Encoder {
+	type ActualSize;
+
+	fn bar(&self) -> Self::Size;
+}
+
+impl<T> Encoder for T where T: SubEncoder {
+	type Size = <Self as SubEncoder>::ActualSize;
+
+	fn foo(&self) -> Self::Size {
+		self.bar() + self.bar()
+	}
+}
+
+pub struct UnitEncoder;
+
+impl SubEncoder for UnitEncoder {
+	type ActualSize = ();
+
+	fn bar(&self) {}
+}
+
+
+fn main() {
+	fun(&UnitEncoder {});
+}
+
+pub fn fun<R: Encoder>(encoder: &R) {
+	encoder.foo();
+}
+EOF