Rollup merge of #83945 - SkiFire13:fix-83924, r=estebank

Add suggestion to reborrow mutable references when they're moved in a for loop

Address #83924

3 files changed, 65 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-83924.fixed b/src/test/ui/issues/issue-83924.fixed
new file mode 100644
index 00000000000..aa40da12b87
--- /dev/null
+++ b/src/test/ui/issues/issue-83924.fixed
@@ -0,0 +1,20 @@
+// run-rustfix
+
+fn main() {
+    let mut values = vec![10, 11, 12];
+    let v = &mut values;
+
+    let mut max = 0;
+
+    for n in &mut *v {
+        max = std::cmp::max(max, *n);
+    }
+
+    println!("max is {}", max);
+    println!("Converting to percentages of maximum value...");
+    for n in v {
+        //~^ ERROR: use of moved value: `v` [E0382]
+        *n = 100 * (*n) / max;
+    }
+    println!("values: {:#?}", values);
+}
diff --git a/src/test/ui/issues/issue-83924.rs b/src/test/ui/issues/issue-83924.rs
new file mode 100644
index 00000000000..22b80fe2f38
--- /dev/null
+++ b/src/test/ui/issues/issue-83924.rs
@@ -0,0 +1,20 @@
+// run-rustfix
+
+fn main() {
+    let mut values = vec![10, 11, 12];
+    let v = &mut values;
+
+    let mut max = 0;
+
+    for n in v {
+        max = std::cmp::max(max, *n);
+    }
+
+    println!("max is {}", max);
+    println!("Converting to percentages of maximum value...");
+    for n in v {
+        //~^ ERROR: use of moved value: `v` [E0382]
+        *n = 100 * (*n) / max;
+    }
+    println!("values: {:#?}", values);
+}
diff --git a/src/test/ui/issues/issue-83924.stderr b/src/test/ui/issues/issue-83924.stderr
new file mode 100644
index 00000000000..682bc323cb0
--- /dev/null
+++ b/src/test/ui/issues/issue-83924.stderr
@@ -0,0 +1,25 @@
+error[E0382]: use of moved value: `v`
+  --> $DIR/issue-83924.rs:15:14
+   |
+LL |     let v = &mut values;
+   |         - move occurs because `v` has type `&mut Vec<i32>`, which does not implement the `Copy` trait
+...
+LL |     for n in v {
+   |              - `v` moved due to this implicit call to `.into_iter()`
+...
+LL |     for n in v {
+   |              ^ value used here after move
+   |
+note: this function takes ownership of the receiver `self`, which moves `v`
+  --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
+   |
+LL |     fn into_iter(self) -> Self::IntoIter;
+   |                  ^^^^
+help: consider creating a fresh reborrow of `v` here
+   |
+LL |     for n in &mut *v {
+   |              ^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0382`.