1 files changed, 26 insertions, 0 deletions
diff --git a/src/test/ui/traits/inheritance/num5.rs b/src/test/ui/traits/inheritance/num5.rs
new file mode 100644
index 000000000..f478618f7
--- /dev/null
+++ b/src/test/ui/traits/inheritance/num5.rs
@@ -0,0 +1,26 @@
+// run-pass
+// pretty-expanded FIXME #23616
+
+pub trait NumCast: Sized {
+    fn from(i: i32) -> Option<Self>;
+}
+
+pub trait NumExt: PartialEq + NumCast {}
+
+impl NumExt for f32 {}
+impl NumExt for isize {}
+
+impl NumCast for f32 {
+    fn from(i: i32) -> Option<f32> { Some(i as f32) }
+}
+impl NumCast for isize {
+    fn from(i: i32) -> Option<isize> { Some(i as isize) }
+}
+
+fn num_eq_one<T:NumExt>() -> T {
+    NumCast::from(1).unwrap()
+}
+
+pub fn main() {
+    num_eq_one::<isize>(); // you need to actually use the function to trigger the ICE
+}