71b0755a98
Point at statics and consts being mutable borrowed or written to:
```
error[E0594]: cannot assign to immutable static item `NUM`
--> $DIR/E0594.rs:4:5
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LL | static NUM: i32 = 18;
| --------------- this `static` cannot be written to
...
LL | NUM = 20;
| ^^^^^^^^ cannot assign
```
Point at the expression that couldn't be mutably borrowed from a pattern:
```
error[E0596]: cannot borrow data in a `&` reference as mutable
--> $DIR/mut-pattern-of-immutable-borrow.rs:19:14
|
LL | match &arg.field {
| ---------- this cannot be borrowed as mutable
LL | Some(ref mut s) => s.push('a'),
| ^^^^^^^^^ cannot borrow as mutable
```
31 lines
669 B
Rust
31 lines
669 B
Rust
struct S {
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field: Option<String>,
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}
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fn a(arg: &mut S) {
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match arg.field { //~ ERROR cannot move out of `arg.field`
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Some(s) => s.push('a'), //~ ERROR cannot borrow `s` as mutable
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None => {}
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}
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}
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fn b(arg: &mut S) {
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match &arg.field { //~ ERROR cannot move out of a shared reference
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Some(mut s) => s.push('a'),
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None => {}
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}
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}
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fn c(arg: &mut S) {
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match &arg.field {
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Some(ref mut s) => s.push('a'), //~ ERROR cannot borrow data in a `&` reference as mutable
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None => {}
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}
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}
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fn main() {
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let mut s = S {
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field: Some("a".to_owned()),
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};
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a(&mut s);
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b(&mut s);
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c(&mut s);
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}
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