Unions are not PointerLike

2 files changed, 36 insertions, 0 deletions

diff --git a/tests/ui/dyn-star/union.rs b/tests/ui/dyn-star/union.rs
new file mode 100644
index 00000000000..ad3a85a937a
--- /dev/null
+++ b/tests/ui/dyn-star/union.rs
@@ -0,0 +1,16 @@
+#![feature(dyn_star)]
+//~^ WARN the feature `dyn_star` is incomplete and may not be safe to use and/or cause compiler crashes
+
+union Union {
+    x: usize,
+}
+
+trait Trait {}
+impl Trait for Union {}
+
+fn bar(_: dyn* Trait) {}
+
+fn main() {
+    bar(Union { x: 0usize });
+    //~^ ERROR `Union` needs to have the same ABI as a pointer
+}
diff --git a/tests/ui/dyn-star/union.stderr b/tests/ui/dyn-star/union.stderr
new file mode 100644
index 00000000000..906eb4f5163
--- /dev/null
+++ b/tests/ui/dyn-star/union.stderr
@@ -0,0 +1,20 @@
+warning: the feature `dyn_star` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/union.rs:1:12
+   |
+LL | #![feature(dyn_star)]
+   |            ^^^^^^^^
+   |
+   = note: see issue #102425 <https://github.com/rust-lang/rust/issues/102425> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error[E0277]: `Union` needs to have the same ABI as a pointer
+  --> $DIR/union.rs:14:9
+   |
+LL |     bar(Union { x: 0usize });
+   |         ^^^^^^^^^^^^^^^^^^^ `Union` needs to be a pointer-like type
+   |
+   = help: the trait `PointerLike` is not implemented for `Union`
+
+error: aborting due to 1 previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0277`.