3 files changed, 126 insertions, 0 deletions
diff --git a/src/test/ui/rfc-2027-object-safe-for-dispatch/downcast-unsafe-trait-objects.rs b/src/test/ui/rfc-2027-object-safe-for-dispatch/downcast-unsafe-trait-objects.rs
new file mode 100644
index 000000000..fa04f4b12
--- /dev/null
+++ b/src/test/ui/rfc-2027-object-safe-for-dispatch/downcast-unsafe-trait-objects.rs
@@ -0,0 +1,23 @@
+// Check that we if we get ahold of an object unsafe trait
+// object with auto traits and lifetimes, we can downcast it
+//
+// check-pass
+
+#![feature(object_safe_for_dispatch)]
+
+trait Trait: Sized {}
+
+fn downcast_auto(t: &(dyn Trait + Send)) -> &dyn Trait {
+    t
+}
+
+fn downcast_lifetime<'a, 'b, 't>(t: &'a (dyn Trait + 't))
+                                 -> &'b (dyn Trait + 't)
+where
+    'a: 'b,
+    't: 'a + 'b,
+{
+    t
+}
+
+fn main() {}
diff --git a/src/test/ui/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs b/src/test/ui/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs
new file mode 100644
index 000000000..721890db4
--- /dev/null
+++ b/src/test/ui/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs
@@ -0,0 +1,66 @@
+// Check that we can manually implement an object-unsafe trait for its trait object.
+
+// run-pass
+
+#![feature(object_safe_for_dispatch)]
+
+trait Bad {
+    fn stat() -> char {
+        'A'
+    }
+    fn virt(&self) -> char {
+        'B'
+    }
+    fn indirect(&self) -> char {
+        Self::stat()
+    }
+}
+
+trait Good {
+    fn good_virt(&self) -> char {
+        panic!()
+    }
+    fn good_indirect(&self) -> char {
+        panic!()
+    }
+}
+
+impl<'a> Bad for dyn Bad + 'a {
+    fn stat() -> char {
+        'C'
+    }
+    fn virt(&self) -> char {
+        'D'
+    }
+}
+
+struct Struct {}
+
+impl Bad for Struct {}
+
+impl Good for Struct {}
+
+fn main() {
+    let s = Struct {};
+
+    let mut res = String::new();
+
+    // Directly call static.
+    res.push(Struct::stat()); // "A"
+    res.push(<dyn Bad>::stat()); // "AC"
+
+    let good: &dyn Good = &s;
+
+    // These look similar enough...
+    let bad = unsafe { std::mem::transmute::<&dyn Good, &dyn Bad>(good) };
+
+    // Call virtual.
+    res.push(s.virt()); // "ACB"
+    res.push(bad.virt()); // "ACBD"
+
+    // Indirectly call static.
+    res.push(s.indirect()); // "ACBDA"
+    res.push(bad.indirect()); // "ACBDAC"
+
+    assert_eq!(&res, "ACBDAC");
+}
diff --git a/src/test/ui/rfc-2027-object-safe-for-dispatch/static-dispatch-unsafe-object.rs b/src/test/ui/rfc-2027-object-safe-for-dispatch/static-dispatch-unsafe-object.rs
new file mode 100644
index 000000000..df97d2c13
--- /dev/null
+++ b/src/test/ui/rfc-2027-object-safe-for-dispatch/static-dispatch-unsafe-object.rs
@@ -0,0 +1,37 @@
+// Check that we can statically dispatch methods for object
+// unsafe trait objects, directly and indirectly
+//
+// check-pass
+
+#![feature(object_safe_for_dispatch)]
+
+trait Statics {
+    fn plain() {}
+    fn generic<T>() {}
+}
+
+trait Trait: Sized {}
+
+impl<'a> Statics for dyn Trait + 'a {}
+
+fn static_poly<T: Statics + ?Sized>() {
+    T::plain();
+    T::generic::<usize>();
+}
+
+fn inferred_poly<T: Statics + ?Sized>(t: &T) {
+    static_poly::<T>();
+    T::plain();
+    T::generic::<usize>();
+}
+
+fn call(t: &dyn Trait) {
+    static_poly::<dyn Trait>();
+    inferred_poly(t);
+}
+
+fn main() {
+    static_poly::<dyn Trait>();
+    <dyn Trait>::plain();
+    <dyn Trait>::generic::<usize>()
+}