rust/tests/ui/borrowck/issue-83760.fixed
Esteban Küber 98cfed7b97 Suggest cloning and point out obligation errors on move error
When encountering a move error, look for implementations of `Clone` for
the moved type. If there is one, check if all its obligations are met.
If they are, we suggest cloning without caveats. If they aren't, we
suggest cloning while mentioning the unmet obligations, potentially
suggesting `#[derive(Clone)]` when appropriate.

```
error[E0507]: cannot move out of a shared reference
  --> $DIR/suggest-clone-when-some-obligation-is-unmet.rs:20:28
   |
LL |     let mut copy: Vec<U> = map.clone().into_values().collect();
   |                            ^^^^^^^^^^^ ------------- value moved due to this method call
   |                            |
   |                            move occurs because value has type `HashMap<T, U, Hash128_1>`, which does not implement the `Copy` trait
   |
note: `HashMap::<K, V, S>::into_values` takes ownership of the receiver `self`, which moves value
  --> $SRC_DIR/std/src/collections/hash/map.rs:LL:COL
help: you could `clone` the value and consume it, if the `Hash128_1: Clone` trait bound could be satisfied
   |
LL |     let mut copy: Vec<U> = <HashMap<T, U, Hash128_1> as Clone>::clone(&map.clone()).into_values().collect();
   |                            ++++++++++++++++++++++++++++++++++++++++++++           +
help: consider annotating `Hash128_1` with `#[derive(Clone)]`
   |
LL + #[derive(Clone)]
LL | pub struct Hash128_1;
   |
```

Fix #109429.
2023-12-04 21:54:32 +00:00

48 lines
998 B
Rust

// run-rustfix
#![allow(unused_variables, dead_code)]
#[derive(Clone)]
struct Struct;
#[derive(Clone)]
struct Struct2;
// We use a second one here because otherwise when applying suggestions we'd end up with two
// `#[derive(Clone)]` annotations.
fn test1() {
let mut val = Some(Struct);
while let Some(ref foo) = val { //~ ERROR use of moved value
if true {
val = None;
} else {
}
}
}
fn test2() {
let mut foo = Some(Struct);
let _x = foo.clone().unwrap();
if true {
foo = Some(Struct);
} else {
}
let _y = foo; //~ ERROR use of moved value: `foo`
}
fn test3() {
let mut foo = Some(Struct2);
let _x = foo.clone().unwrap();
if true {
foo = Some(Struct2);
} else if true {
foo = Some(Struct2);
} else if true {
foo = Some(Struct2);
} else if true {
foo = Some(Struct2);
} else {
}
let _y = foo; //~ ERROR use of moved value: `foo`
}
fn main() {}