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a754fcaa43
When encountering a case where `let x: T = (val: &T).clone();` and
`T: !Clone`, already mention that the reference is being cloned. We now
also suggest `#[derive(Clone)]` not only on `T` but also on type
parameters to satisfy blanket implementations.
```
error[E0308]: mismatched types
--> $DIR/assignment-of-clone-call-on-ref-due-to-missing-bound.rs:17:39
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LL | let mut x: HashSet<Day> = v.clone();
| ------------ ^^^^^^^^^ expected `HashSet<Day>`, found `&HashSet<Day>`
| |
| expected due to this
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= note: expected struct `HashSet<Day>`
found reference `&HashSet<Day>`
note: `HashSet<Day>` does not implement `Clone`, so `&HashSet<Day>` was cloned instead
--> $DIR/assignment-of-clone-call-on-ref-due-to-missing-bound.rs:17:39
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LL | let mut x: HashSet<Day> = v.clone();
| ^
= help: `Clone` is not implemented because the trait bound `Day: Clone` is not satisfied
help: consider annotating `Day` with `#[derive(Clone)]`
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LL + #[derive(Clone)]
LL | enum Day {
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```
Case taken from # #41825.
30 lines
557 B
Rust
30 lines
557 B
Rust
// run-rustfix
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#![allow(unused_variables, dead_code)]
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use std::collections::BTreeMap;
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use std::collections::HashSet;
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#[derive(Debug,Eq,PartialEq,Hash)]
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enum Day {
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Mon,
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}
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struct Class {
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days: BTreeMap<u32, HashSet<Day>>
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}
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impl Class {
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fn do_stuff(&self) {
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for (_, v) in &self.days {
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let mut x: HashSet<Day> = v.clone(); //~ ERROR
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let y: Vec<Day> = x.drain().collect();
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println!("{:?}", x);
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}
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}
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}
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fn fail() {
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let c = Class { days: BTreeMap::new() };
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c.do_stuff();
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}
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fn main() {}
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