Normalize super trait bounds when confirming object candidates

1 files changed, 26 insertions, 0 deletions

diff --git a/src/test/ui/associated-types/object-normalization.rs b/src/test/ui/associated-types/object-normalization.rs
new file mode 100644
index 00000000000..1f93248e10e
--- /dev/null
+++ b/src/test/ui/associated-types/object-normalization.rs
@@ -0,0 +1,26 @@
+// ignore-tidy-linelength
+
+// Check that we normalize super predicates for object candidates.
+
+// check-pass
+
+use std::ops::Index;
+
+fn next<'a, T>(s: &'a mut dyn SVec<Item = T, Output = T>) {
+    // To prove
+    // `dyn SVec<Item = T, Output = T>: SVec`
+    // we need to show
+    // `dyn SVec<Item = T, Output = T> as Index>::Output == <dyn SVec<Item = T, Output = T> as SVec>::Item`
+    // which, with the current normalization strategy, has to be eagerly
+    // normalized to:
+    // `dyn SVec<Item = T, Output = T> as Index>::Output == T`.
+    let _ = s.len();
+}
+
+trait SVec: Index<usize, Output = <Self as SVec>::Item> {
+    type Item;
+
+    fn len(&self) -> usize;
+}
+
+fn main() {}