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78d29ad8d6
Sometimes move errors are because of a misplaced `continue`, but we didn't
surface that anywhere. Now when there are more than one set of nested loops
we show them out and point at the `continue` and `break` expressions within
that might need to go elsewhere.
```
error[E0382]: use of moved value: `foo`
--> $DIR/nested-loop-moved-value-wrong-continue.rs:46:18
|
LL | for foo in foos {
| ---
| |
| this reinitialization might get skipped
| move occurs because `foo` has type `String`, which does not implement the `Copy` trait
...
LL | for bar in &bars {
| ---------------- inside of this loop
...
LL | baz.push(foo);
| --- value moved here, in previous iteration of loop
...
LL | qux.push(foo);
| ^^^ value used here after move
|
note: verify that your loop breaking logic is correct
--> $DIR/nested-loop-moved-value-wrong-continue.rs:41:17
|
LL | for foo in foos {
| ---------------
...
LL | for bar in &bars {
| ----------------
...
LL | continue;
| ^^^^^^^^ this `continue` advances the loop at line 33
help: consider moving the expression out of the loop so it is only moved once
|
LL ~ let mut value = baz.push(foo);
LL ~ for bar in &bars {
LL |
...
LL | if foo == *bar {
LL ~ value;
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help: consider cloning the value if the performance cost is acceptable
|
LL | baz.push(foo.clone());
| ++++++++
```
Fix #92531.
60 lines
1.3 KiB
Rust
60 lines
1.3 KiB
Rust
fn iter<T>(vec: Vec<T>) -> impl Iterator<Item = T> {
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vec.into_iter()
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}
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fn foo() {
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let vec = vec!["one", "two", "three"];
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while let Some(item) = iter(vec).next() { //~ ERROR use of moved value
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println!("{:?}", item);
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}
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}
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fn bar() {
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let vec = vec!["one", "two", "three"];
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loop {
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let Some(item) = iter(vec).next() else { //~ ERROR use of moved value
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break;
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};
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println!("{:?}", item);
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}
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}
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fn baz() {
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let vec = vec!["one", "two", "three"];
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loop {
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let item = iter(vec).next(); //~ ERROR use of moved value
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if item.is_none() {
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break;
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}
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println!("{:?}", item);
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}
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}
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fn qux() {
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let vec = vec!["one", "two", "three"];
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loop {
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if let Some(item) = iter(vec).next() { //~ ERROR use of moved value
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println!("{:?}", item);
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break;
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}
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}
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}
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fn zap() {
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loop {
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let vec = vec!["one", "two", "three"];
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loop {
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loop {
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loop {
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if let Some(item) = iter(vec).next() { //~ ERROR use of moved value
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println!("{:?}", item);
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break;
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}
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}
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}
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}
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}
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}
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fn main() {
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foo();
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bar();
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baz();
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qux();
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zap();
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}
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