try to fix lvalue ops for real

Hopefully this is the last PR needed.

Fixes #41726.
Fixes #41742.
Fixes #41774.

1 files changed, 35 insertions, 0 deletions

diff --git a/src/test/compile-fail/issue-41742.rs b/src/test/compile-fail/issue-41742.rs
new file mode 100644
index 00000000000..067531e036a
--- /dev/null
+++ b/src/test/compile-fail/issue-41742.rs
@@ -0,0 +1,35 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::ops::{Index, IndexMut};
+
+struct S;
+struct H;
+
+impl S {
+    fn f(&mut self) {}
+}
+
+impl Index<u32> for H {
+    type Output = S;
+    fn index(&self, index: u32) -> &S {
+        unimplemented!()
+    }
+}
+
+impl IndexMut<u32> for H {
+    fn index_mut(&mut self, index: u32) -> &mut S {
+        unimplemented!()
+    }
+}
+
+fn main() {
+    H["?"].f(); //~ ERROR mismatched types
+}