From 1b5ac399082253288772dc1dabaa9d5458c927a9 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Tue, 4 Apr 2023 00:28:05 +0000
Subject: [PATCH] dyn* is a valid const

---
 .../src/transform/check_consts/check.rs               |  2 +-
 tests/ui/dyn-star/const-and-static.rs                 | 10 ++++++++++
 tests/ui/dyn-star/const-and-static.stderr             | 11 +++++++++++
 3 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 tests/ui/dyn-star/const-and-static.rs
 create mode 100644 tests/ui/dyn-star/const-and-static.stderr

diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs
index d6110a050f2dc..20c0852fe33a9 100644
--- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs
+++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs
@@ -553,7 +553,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
             }
 
             Rvalue::Cast(CastKind::DynStar, _, _) => {
-                unimplemented!()
+                // `dyn*` coercion is implemented for CTFE.
             }
 
             Rvalue::Cast(_, _, _) => {}
diff --git a/tests/ui/dyn-star/const-and-static.rs b/tests/ui/dyn-star/const-and-static.rs
new file mode 100644
index 0000000000000..551b072abfab8
--- /dev/null
+++ b/tests/ui/dyn-star/const-and-static.rs
@@ -0,0 +1,10 @@
+// check-pass
+
+#![feature(dyn_star)]
+//~^ WARN the feature `dyn_star` is incomplete
+
+const C: dyn* Send + Sync = &();
+
+static S: dyn* Send + Sync = &();
+
+fn main() {}
diff --git a/tests/ui/dyn-star/const-and-static.stderr b/tests/ui/dyn-star/const-and-static.stderr
new file mode 100644
index 0000000000000..df8f42fb0f573
--- /dev/null
+++ b/tests/ui/dyn-star/const-and-static.stderr
@@ -0,0 +1,11 @@
+warning: the feature `dyn_star` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/const-and-static.rs:3:12
+   |
+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
+
+warning: 1 warning emitted
+