1 files changed, 25 insertions, 0 deletions
diff --git a/tests/ui/unsafe/unsafe-assign.rs b/tests/ui/unsafe/unsafe-assign.rs
new file mode 100644
index 00000000000..15273165b5e
--- /dev/null
+++ b/tests/ui/unsafe/unsafe-assign.rs
@@ -0,0 +1,25 @@
+// revisions: mirunsafeck thirunsafeck
+// [thirunsafeck]compile-flags: -Z thir-unsafeck
+
+#![feature(rustc_attrs)]
+#![allow(unused,dead_code)]
+
+fn nested_field() {
+    #[rustc_layout_scalar_valid_range_start(1)]
+    struct NonZero<T>(T);
+
+    let mut foo = unsafe { NonZero((1,)) };
+    foo.0.0 = 0;
+    //~^ ERROR: mutation of layout constrained field is unsafe
+}
+
+fn block() {
+    #[rustc_layout_scalar_valid_range_start(1)]
+    struct NonZero<T>(T);
+
+    let mut foo = unsafe { NonZero((1,)) };
+    { foo.0 }.0 = 0;
+    // ^ not unsafe because the result of the block expression is a new place
+}
+
+fn main() {}