From 98f4b20abc9ad5ff77874119bbec305f4c7c6226 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Sat, 3 Sep 2022 19:13:17 +0000
Subject: Also suggest dereferencing LHS when both &mut T and T are valid binop
 LHS

---
 src/test/ui/typeck/assign-non-lval-needs-deref.rs     | 19 +++++++++++++++++++
 src/test/ui/typeck/assign-non-lval-needs-deref.stderr | 16 ++++++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 src/test/ui/typeck/assign-non-lval-needs-deref.rs
 create mode 100644 src/test/ui/typeck/assign-non-lval-needs-deref.stderr

(limited to 'src')

diff --git a/src/test/ui/typeck/assign-non-lval-needs-deref.rs b/src/test/ui/typeck/assign-non-lval-needs-deref.rs
new file mode 100644
index 00000000000..c979d76b4f4
--- /dev/null
+++ b/src/test/ui/typeck/assign-non-lval-needs-deref.rs
@@ -0,0 +1,19 @@
+// issue #101376
+
+use std::ops::AddAssign;
+struct Foo;
+
+impl AddAssign<()> for Foo {
+    fn add_assign(&mut self, _: ()) {}
+}
+
+impl AddAssign<()> for &mut Foo {
+    fn add_assign(&mut self, _: ()) {}
+}
+
+fn main() {
+    (&mut Foo) += ();
+    //~^ ERROR invalid left-hand side of assignment
+    //~| NOTE cannot assign to this expression
+    //~| HELP consider dereferencing the left-hand side of this operation
+}
diff --git a/src/test/ui/typeck/assign-non-lval-needs-deref.stderr b/src/test/ui/typeck/assign-non-lval-needs-deref.stderr
new file mode 100644
index 00000000000..ee83b145321
--- /dev/null
+++ b/src/test/ui/typeck/assign-non-lval-needs-deref.stderr
@@ -0,0 +1,16 @@
+error[E0067]: invalid left-hand side of assignment
+  --> $DIR/assign-non-lval-needs-deref.rs:15:16
+   |
+LL |     (&mut Foo) += ();
+   |     ---------- ^^
+   |     |
+   |     cannot assign to this expression
+   |
+help: consider dereferencing the left-hand side of this operation
+   |
+LL |     *(&mut Foo) += ();
+   |     +
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0067`.
-- 
cgit 1.4.1-3-g733a5