1 files changed, 29 insertions, 0 deletions
diff --git a/tests/ui/transmutability/primitives/unit.rs b/tests/ui/transmutability/primitives/unit.rs
new file mode 100644
index 00000000000..1975a61de98
--- /dev/null
+++ b/tests/ui/transmutability/primitives/unit.rs
@@ -0,0 +1,29 @@
+//! The unit type, `()`, should be one byte.
+
+#![crate_type = "lib"]
+#![feature(transmutability)]
+#![allow(dead_code)]
+
+mod assert {
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
+
+    pub fn is_transmutable<Src, Dst, Context>()
+    where
+        Dst: BikeshedIntrinsicFrom<Src, Context, {
+            Assume::ALIGNMENT
+                .and(Assume::LIFETIMES)
+                .and(Assume::SAFETY)
+                .and(Assume::VALIDITY)
+        }>
+    {}
+}
+
+#[repr(C)]
+struct Zst;
+
+fn should_have_correct_size() {
+    struct Context;
+    assert::is_transmutable::<(), Zst, Context>();
+    assert::is_transmutable::<Zst, (), Context>();
+    assert::is_transmutable::<(), u8, Context>(); //~ ERROR cannot be safely transmuted
+}