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When encountering multiple mutable borrows, suggest cloning and adding
derive annotations as needed.
```
error[E0596]: cannot borrow `sm.x` as mutable, as it is behind a `&` reference
--> $DIR/accidentally-cloning-ref-borrow-error.rs:32:9
|
LL | foo(&mut sm.x);
| ^^^^^^^^^ `sm` is a `&` reference, so the data it refers to cannot be borrowed as mutable
|
help: `Str` doesn't implement `Clone`, so this call clones the reference `&Str`
--> $DIR/accidentally-cloning-ref-borrow-error.rs:31:21
|
LL | let mut sm = sr.clone();
| ^^^^^^^
help: consider annotating `Str` with `#[derive(Clone)]`
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LL + #[derive(Clone)]
LL | struct Str {
|
help: consider specifying this binding's type
|
LL | let mut sm: &mut Str = sr.clone();
| ++++++++++
```
```
error[E0596]: cannot borrow `*inner` as mutable, as it is behind a `&` reference
--> $DIR/issue-91206.rs:14:5
|
LL | inner.clear();
| ^^^^^ `inner` is a `&` reference, so the data it refers to cannot be borrowed as mutable
|
help: you can `clone` the `Vec<usize>` value and consume it, but this might not be your desired behavior
--> $DIR/issue-91206.rs:11:17
|
LL | let inner = client.get_inner_ref();
| ^^^^^^^^^^^^^^^^^^^^^^
help: consider specifying this binding's type
|
LL | let inner: &mut Vec<usize> = client.get_inner_ref();
| +++++++++++++++++
```
31 lines
1.2 KiB
Rust
31 lines
1.2 KiB
Rust
fn main() {
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let mut test = Vec::new();
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let rofl: &Vec<Vec<i32>> = &mut test;
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//~^ HELP consider changing this binding's type
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//~| HELP you can `clone` the `Vec<Vec<i32>>` value and consume it, but this might not be your desired behavior
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rofl.push(Vec::new());
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//~^ ERROR cannot borrow `*rofl` as mutable, as it is behind a `&` reference
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//~| NOTE `rofl` is a `&` reference, so the data it refers to cannot be borrowed as mutable
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let mut mutvar = 42;
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let r = &mutvar;
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//~^ HELP consider changing this to be a mutable reference
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*r = 0;
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//~^ ERROR cannot assign to `*r`, which is behind a `&` reference
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//~| NOTE `r` is a `&` reference, so the data it refers to cannot be written
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#[rustfmt::skip]
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let x: &usize = &mut{0};
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//~^ HELP consider changing this binding's type
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*x = 1;
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//~^ ERROR cannot assign to `*x`, which is behind a `&` reference
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//~| NOTE `x` is a `&` reference, so the data it refers to cannot be written
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#[rustfmt::skip]
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let y: &usize = &mut(0);
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//~^ HELP consider changing this binding's type
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*y = 1;
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//~^ ERROR cannot assign to `*y`, which is behind a `&` reference
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//~| NOTE `y` is a `&` reference, so the data it refers to cannot be written
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}
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