1 files changed, 86 insertions, 0 deletions
diff --git a/tests/ui/traits/trait-upcasting/basic.rs b/tests/ui/traits/trait-upcasting/basic.rs
new file mode 100644
index 00000000000..570ec5160bf
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/basic.rs
@@ -0,0 +1,86 @@
+// run-pass
+
+#![feature(trait_upcasting)]
+
+trait Foo: PartialEq<i32> + std::fmt::Debug + Send + Sync {
+    fn a(&self) -> i32 {
+        10
+    }
+
+    fn z(&self) -> i32 {
+        11
+    }
+
+    fn y(&self) -> i32 {
+        12
+    }
+}
+
+trait Bar: Foo {
+    fn b(&self) -> i32 {
+        20
+    }
+
+    fn w(&self) -> i32 {
+        21
+    }
+}
+
+trait Baz: Bar {
+    fn c(&self) -> i32 {
+        30
+    }
+}
+
+impl Foo for i32 {
+    fn a(&self) -> i32 {
+        100
+    }
+}
+
+impl Bar for i32 {
+    fn b(&self) -> i32 {
+        200
+    }
+}
+
+impl Baz for i32 {
+    fn c(&self) -> i32 {
+        300
+    }
+}
+
+fn main() {
+    let baz: &dyn Baz = &1;
+    let _: &dyn std::fmt::Debug = baz;
+    assert_eq!(*baz, 1);
+    assert_eq!(baz.a(), 100);
+    assert_eq!(baz.b(), 200);
+    assert_eq!(baz.c(), 300);
+    assert_eq!(baz.z(), 11);
+    assert_eq!(baz.y(), 12);
+    assert_eq!(baz.w(), 21);
+
+    let bar: &dyn Bar = baz;
+    let _: &dyn std::fmt::Debug = bar;
+    assert_eq!(*bar, 1);
+    assert_eq!(bar.a(), 100);
+    assert_eq!(bar.b(), 200);
+    assert_eq!(bar.z(), 11);
+    assert_eq!(bar.y(), 12);
+    assert_eq!(bar.w(), 21);
+
+    let foo: &dyn Foo = baz;
+    let _: &dyn std::fmt::Debug = foo;
+    assert_eq!(*foo, 1);
+    assert_eq!(foo.a(), 100);
+    assert_eq!(foo.z(), 11);
+    assert_eq!(foo.y(), 12);
+
+    let foo: &dyn Foo = bar;
+    let _: &dyn std::fmt::Debug = foo;
+    assert_eq!(*foo, 1);
+    assert_eq!(foo.a(), 100);
+    assert_eq!(foo.z(), 11);
+    assert_eq!(foo.y(), 12);
+}