Auto merge of #101411 - matthiaskrgr:rollup-uj24yb5, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #101322 (Fix internal doc link)
 - #101385 (updated description of File struct in std::fs)
 - #101388 (Don't delay invalid LHS bug unless it will be covered by an error in `check_overloaded_binop`)
 - #101394 (Forbid mixing `System` with direct sytem allocator calls)
 - #101397 (rustdoc: remove redundant mobile-sized `.source nav:not(.sidebar).sub`)
 - #101401 (Make `char::is_lowercase` and `char::is_uppercase` const)
 - #101407 (Remove duplicated test (superseeded by search-form-elements.goml))

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

2 files changed, 35 insertions, 0 deletions

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`.