1 files changed, 29 insertions, 0 deletions
diff --git a/third_party/rust/bytemuck/tests/std_tests.rs b/third_party/rust/bytemuck/tests/std_tests.rs
new file mode 100644
index 0000000000..0e0fb48710
--- /dev/null
+++ b/third_party/rust/bytemuck/tests/std_tests.rs
@@ -0,0 +1,29 @@
+//! The integration tests seem to always have `std` linked, so things that would
+//! depend on that can go here.
+
+use bytemuck::*;
+
+#[test]
+fn test_transparent_vtabled() {
+  use core::fmt::Display;
+
+  #[repr(transparent)]
+  struct DisplayTraitObj(dyn Display);
+
+  unsafe impl TransparentWrapper<dyn Display> for DisplayTraitObj {}
+
+  impl Display for DisplayTraitObj {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+      self.0.fmt(f)
+    }
+  }
+
+  let v = DisplayTraitObj::wrap_ref(&5i32);
+  let s = format!("{}", v);
+  assert_eq!(s, "5");
+
+  let mut x = 100i32;
+  let v_mut = DisplayTraitObj::wrap_mut(&mut x);
+  let s = format!("{}", v_mut);
+  assert_eq!(s, "100");
+}