1 files changed, 20 insertions, 0 deletions
diff --git a/src/test/ui/let-else/let-else-binding-explicit-mut.rs b/src/test/ui/let-else/let-else-binding-explicit-mut.rs
new file mode 100644
index 000000000..dbe4715b1
--- /dev/null
+++ b/src/test/ui/let-else/let-else-binding-explicit-mut.rs
@@ -0,0 +1,20 @@
+// from rfc2005 test suite
+
+#![feature(let_else)]
+
+// Verify the binding mode shifts - only when no `&` are auto-dereferenced is the
+// final default binding mode mutable.
+
+fn main() {
+    let Some(n) = &&Some(5i32) else { return };
+    *n += 1; //~ ERROR cannot assign to `*n`, which is behind a `&` reference
+    let _ = n;
+
+    let Some(n) = &mut &Some(5i32) else { return };
+    *n += 1; //~ ERROR cannot assign to `*n`, which is behind a `&` reference
+    let _ = n;
+
+    let Some(n) = &&mut Some(5i32) else { return };
+    *n += 1; //~ ERROR cannot assign to `*n`, which is behind a `&` reference
+    let _ = n;
+}