1 files changed, 33 insertions, 0 deletions
diff --git a/src/test/ui/consts/issue-79690.rs b/src/test/ui/consts/issue-79690.rs
new file mode 100644
index 000000000..56747bf5a
--- /dev/null
+++ b/src/test/ui/consts/issue-79690.rs
@@ -0,0 +1,33 @@
+// ignore-32bit
+// This test gives a different error on 32-bit architectures.
+// stderr-per-bitwidth
+
+union Transmute<T: Copy, U: Copy> {
+    t: T,
+    u: U,
+}
+trait Bar {
+    fn bar(&self) -> u32;
+}
+struct Foo {
+    foo: u32,
+    bar: bool,
+}
+impl Bar for Foo {
+    fn bar(&self) -> u32 {
+        self.foo
+    }
+}
+#[derive(Copy, Clone)]
+struct Fat<'a>(&'a Foo, &'static VTable);
+struct VTable {
+    size: Foo,
+}
+const FOO: &dyn Bar = &Foo {
+    foo: 128,
+    bar: false,
+};
+const G: Fat = unsafe { Transmute { t: FOO }.u };
+//~^ ERROR it is undefined behavior to use this value
+
+fn main() {}