mirror of
https://github.com/rust-lang/rust
synced 2024-10-14 12:33:57 +00:00
14473adf42
When encountering a move error on a value within a loop of any kind,
identify if the moved value belongs to a call expression that should not
be cloned and avoid the semantically incorrect suggestion. Also try to
suggest moving the call expression outside of the loop instead.
```
error[E0382]: use of moved value: `vec`
--> $DIR/recreating-value-in-loop-condition.rs:6:33
|
LL | let vec = vec!["one", "two", "three"];
| --- move occurs because `vec` has type `Vec<&str>`, which does not implement the `Copy` trait
LL | while let Some(item) = iter(vec).next() {
| ----------------------------^^^--------
| | |
| | value moved here, in previous iteration of loop
| inside of this loop
|
note: consider changing this parameter type in function `iter` to borrow instead if owning the value isn't necessary
--> $DIR/recreating-value-in-loop-condition.rs:1:17
|
LL | fn iter<T>(vec: Vec<T>) -> impl Iterator<Item = T> {
| ---- ^^^^^^ this parameter takes ownership of the value
| |
| in this function
help: consider moving the expression out of the loop so it is only moved once
|
LL ~ let mut value = iter(vec);
LL ~ while let Some(item) = value.next() {
|
```
We use the presence of a `break` in the loop that would be affected by
the moved value as a heuristic for "shouldn't be cloned".
Fix #121466.
32 lines
1.2 KiB
Plaintext
32 lines
1.2 KiB
Plaintext
error[E0382]: use of moved value: `value`
|
|
--> $DIR/mut-borrow-in-loop-2.rs:30:23
|
|
|
|
|
LL | fn this_does_not<'a, R>(value: &'a mut Events<R>) {
|
|
| ----- move occurs because `value` has type `&mut Events<R>`, which does not implement the `Copy` trait
|
|
LL | for _ in 0..3 {
|
|
| ------------- inside of this loop
|
|
LL | Other::handle(value);
|
|
| ^^^^^ value moved here, in previous iteration of loop
|
|
|
|
|
note: consider changing this parameter type in function `handle` to borrow instead if owning the value isn't necessary
|
|
--> $DIR/mut-borrow-in-loop-2.rs:8:22
|
|
|
|
|
LL | fn handle(value: T) -> Self;
|
|
| ------ ^ this parameter takes ownership of the value
|
|
| |
|
|
| in this function
|
|
help: consider moving the expression out of the loop so it is only moved once
|
|
|
|
|
LL ~ let mut value = Other::handle(value);
|
|
LL ~ for _ in 0..3 {
|
|
LL ~ value;
|
|
|
|
|
help: consider creating a fresh reborrow of `value` here
|
|
|
|
|
LL | Other::handle(&mut *value);
|
|
| ++++++
|
|
|
|
error: aborting due to 1 previous error
|
|
|
|
For more information about this error, try `rustc --explain E0382`.
|