rust/tests/ui/did_you_mean/issue-38147-3.rs

struct Qux<'a> {
    s: &'a String
}

impl<'a> Qux<'a> {
    fn f(&self) {
        self.s.push('x');
        //~^ ERROR cannot borrow `*self.s` as mutable, as it is behind a `&` reference
    }
}

fn main() {}
Point to immutable arg/fields when trying to use as &mut Point to immutable borrow arguments and fields when trying to use them as mutable borrows. Add label to primary span on "cannot borrow as mutable" errors. Present the following output when trying to access an immutable borrow's field as mutable: ``` error[E0389]: cannot borrow data mutably in a `&` reference --> $DIR/issue-38147-1.rs:27:9 \| 26 \| fn f(&self) { \| ----- use `&mut self` here to make mutable 27 \| f.s.push('x'); \| ^^^ assignment into an immutable reference ``` And the following when trying to access an immutable struct field as mutable: ``` error: cannot borrow immutable borrowed content `*self.s` as mutable --> $DIR/issue-38147-3.rs:17:9 \| 12 \| s: &'a String \| ------------- use `&'a mut String` here to make mutable ...\| 16 \| fn f(&self) { \| ----- use `&mut self` here to make mutable 17 \| self.s.push('x'); \| ^^^^^^ cannot borrow as mutable ``` 2017-01-17 07:42:11 +00:00			`struct Qux<'a> {`
			`s: &'a String`
			`}`

			`impl<'a> Qux<'a> {`
			`fn f(&self) {`
Reword trying to operate in immutable fields The previous message ("cannot assign/mutably borrow immutable field") when trying to modify a field of an immutable binding gave the (incorrect) impression that fields can be mutable independently of their ADT's binding. Slightly reword the message to read "cannot assign/mutably borrow field of immutable binding". 2017-12-31 23:32:41 +00:00			`self.s.push('x');`
update tests for migrate mode by default 2019-04-22 07:40:08 +00:00			//~^ ERROR cannot borrow `*self.s` as mutable, as it is behind a `&` reference
Point to immutable arg/fields when trying to use as &mut Point to immutable borrow arguments and fields when trying to use them as mutable borrows. Add label to primary span on "cannot borrow as mutable" errors. Present the following output when trying to access an immutable borrow's field as mutable: ``` error[E0389]: cannot borrow data mutably in a `&` reference --> $DIR/issue-38147-1.rs:27:9 \| 26 \| fn f(&self) { \| ----- use `&mut self` here to make mutable 27 \| f.s.push('x'); \| ^^^ assignment into an immutable reference ``` And the following when trying to access an immutable struct field as mutable: ``` error: cannot borrow immutable borrowed content `*self.s` as mutable --> $DIR/issue-38147-3.rs:17:9 \| 12 \| s: &'a String \| ------------- use `&'a mut String` here to make mutable ...\| 16 \| fn f(&self) { \| ----- use `&mut self` here to make mutable 17 \| self.s.push('x'); \| ^^^^^^ cannot borrow as mutable ``` 2017-01-17 07:42:11 +00:00			`}`
			`}`

			`fn main() {}`