mirror of
https://github.com/rust-lang/rust.git
synced 2026-04-26 13:01:27 +03:00
Esteban Küber
73fe905f3c
```
error[E0277]: the trait bound `Rc<RefCell<S>>: Borrow<S>` is not satisfied
--> $DIR/shadowed-intrinsic-method-deref.rs:16:22
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LL | let sb : &S = &s.borrow();
| ^^^^^^ the trait `Borrow<S>` is not implemented for `Rc<RefCell<S>>`
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help: the trait `Borrow<S>` is not implemented for `Rc<RefCell<S>>`
but trait `Borrow<RefCell<S>>` is implemented for it
--> $SRC_DIR/alloc/src/rc.rs:LL:COL
= help: for that trait implementation, expected `RefCell<S>`, found `S`
= note: there's an inherent method on `RefCell<S>` of the same name, which can be auto-dereferenced from `&RefCell<T>`
help: to access the inherent method on `RefCell<S>`, use the fully-qualified path
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LL - let sb : &S = &s.borrow();
LL + let sb : &S = &RefCell::borrow(&s);
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```
In the example above, method `borrow` is available both on `<RefCell<S> as Borrow<S>>` *and* on `RefCell<S>`. Adding the import `use std::borrow::Borrow;` causes `s.borrow()` to find the former instead of the latter. We now point out that the other exists, and provide a suggestion on how to call it.
22 lines
635 B
Rust
22 lines
635 B
Rust
//@ run-rustfix
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#![allow(unused_imports)]
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use std::rc::Rc;
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use std::cell::RefCell;
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use std::borrow::Borrow; // Without this import, the code would compile.
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pub struct S {
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flag: bool,
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}
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type SCell = Rc<RefCell<S>>;
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fn main() {
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// Type annotations just for clarity
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let s : SCell = Rc::new(RefCell::new(S {flag: false}));
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let sb : &S = &s.borrow();
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//~^ ERROR: the trait bound `Rc<RefCell<S>>: Borrow<S>` is not satisfied [E0277]
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//~| NOTE: the trait `Borrow<S>` is not implemented for `Rc<RefCell<S>>`
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//~| NOTE: there's an inherent method on `RefCell<S>` of the same name
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println!("{:?}", sb.flag);
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}
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