1 files changed, 27 insertions, 0 deletions
diff --git a/src/test/ui/union/union-transmute.rs b/src/test/ui/union/union-transmute.rs
new file mode 100644
index 000000000..1a3b32d55
--- /dev/null
+++ b/src/test/ui/union/union-transmute.rs
@@ -0,0 +1,27 @@
+// run-pass
+// revisions: mirunsafeck thirunsafeck
+// [thirunsafeck]compile-flags: -Z thir-unsafeck
+
+union U {
+    a: (u8, u8),
+    b: u16,
+}
+
+union W {
+    a: u32,
+    b: f32,
+}
+
+fn main() {
+    unsafe {
+        let mut u = U { a: (1, 1) };
+        assert_eq!(u.b, (1 << 8) + 1);
+        u.b = (2 << 8) + 2;
+        assert_eq!(u.a, (2, 2));
+
+        let mut w = W { a: 0b0_11111111_00000000000000000000000 };
+        assert_eq!(w.b, f32::INFINITY);
+        w.b = f32::NEG_INFINITY;
+        assert_eq!(w.a, 0b1_11111111_00000000000000000000000);
+    }
+}