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When encountering a for loop that is rejected by the borrow checker because it is being advanced within its body, provide a structured suggestion for `while let Some(pat) = iter.next()`.
79 lines
3.1 KiB
Plaintext
79 lines
3.1 KiB
Plaintext
error[E0499]: cannot borrow `chars` as mutable more than once at a time
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--> $DIR/issue-102972.rs:6:9
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LL | for _c in chars.by_ref() {
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| --------------
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| first mutable borrow occurs here
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| first borrow later used here
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LL | chars.next();
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| ^^^^^ second mutable borrow occurs here
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= note: a for loop advances the iterator for you, the result is stored in `_c`
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help: if you want to call `next` on a iterator within the loop, consider using `while let`
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LL ~ let iter = chars.by_ref();
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LL ~ while let Some(_c) = iter.next() {
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LL ~ iter.next();
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error[E0382]: borrow of moved value: `iter`
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--> $DIR/issue-102972.rs:14:9
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LL | let mut iter = v.iter();
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| -------- move occurs because `iter` has type `std::slice::Iter<'_, i32>`, which does not implement the `Copy` trait
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LL | for _i in iter {
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| ---- `iter` moved due to this implicit call to `.into_iter()`
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LL | iter.next();
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| ^^^^ value borrowed here after move
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= note: a for loop advances the iterator for you, the result is stored in `_i`
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note: `into_iter` takes ownership of the receiver `self`, which moves `iter`
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--> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
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help: if you want to call `next` on a iterator within the loop, consider using `while let`
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LL | while let Some(_i) = iter.next() {
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| ~~~~~~~~~~~~~~~ ~~~ +++++++
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error[E0499]: cannot borrow `i` as mutable more than once at a time
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--> $DIR/issue-102972.rs:22:9
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LL | for () in i.by_ref() {
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| ----------
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| first mutable borrow occurs here
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| first borrow later used here
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LL | i.next();
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| ^ second mutable borrow occurs here
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= note: a for loop advances the iterator for you, the result is stored in its pattern
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help: if you want to call `next` on a iterator within the loop, consider using `while let`
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LL ~ let iter = i.by_ref();
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LL ~ while let Some(()) = iter.next() {
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LL ~ iter.next();
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error[E0382]: borrow of moved value: `iter`
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--> $DIR/issue-102972.rs:30:9
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LL | let mut iter = v.iter();
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| -------- move occurs because `iter` has type `std::slice::Iter<'_, ()>`, which does not implement the `Copy` trait
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LL | for () in iter {
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| ---- `iter` moved due to this implicit call to `.into_iter()`
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LL | iter.next();
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| ^^^^ value borrowed here after move
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= note: a for loop advances the iterator for you, the result is stored in its pattern
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note: `into_iter` takes ownership of the receiver `self`, which moves `iter`
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--> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
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help: if you want to call `next` on a iterator within the loop, consider using `while let`
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LL | while let Some(()) = iter.next() {
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| ~~~~~~~~~~~~~~~ ~~~ +++++++
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error: aborting due to 4 previous errors
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Some errors have detailed explanations: E0382, E0499.
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For more information about an error, try `rustc --explain E0382`.
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