rust/tests/ui/borrowck/borrowck-struct-update-with-dtor.rs
Esteban Küber d578ac9e47 Account for move error in the spread operator on struct literals
We attempt to suggest an appropriate clone for move errors on expressions
like `S { ..s }` where a field isn't `Copy`. If we can't suggest, we still don't
emit the incorrect suggestion of `S { ..s }.clone()`.

```
error[E0509]: cannot move out of type `S<K>`, which implements the `Drop` trait
  --> $DIR/borrowck-struct-update-with-dtor.rs:28:19
   |
LL |         let _s2 = S { a: 2, ..s0 };
   |                   ^^^^^^^^^^^^^^^^
   |                   |
   |                   cannot move out of here
   |                   move occurs because `s0.c` has type `K`, which does not implement the `Copy` trait
   |
help: clone the value from the field instead of using the spread operator syntax
   |
LL |         let _s2 = S { a: 2, c: s0.c.clone(), ..s0 };
   |                           +++++++++++++++++
```
```
error[E0509]: cannot move out of type `S<()>`, which implements the `Drop` trait
  --> $DIR/borrowck-struct-update-with-dtor.rs:20:19
   |
LL |         let _s2 = S { a: 2, ..s0 };
   |                   ^^^^^^^^^^^^^^^^
   |                   |
   |                   cannot move out of here
   |                   move occurs because `s0.b` has type `B`, which does not implement the `Copy` trait
   |
note: `B` doesn't implement `Copy` or `Clone`
  --> $DIR/borrowck-struct-update-with-dtor.rs:4:1
   |
LL | struct B;
   | ^^^^^^^^
help: if `B` implemented `Clone`, you could clone the value from the field instead of using the spread operator syntax
   |
LL |         let _s2 = S { a: 2, b: s0.b.clone(), ..s0 };
   |                           +++++++++++++++++
```
2024-04-11 16:41:42 +00:00

65 lines
1.3 KiB
Rust

// Issue 4691: Ensure that functional-struct-update can only copy, not
// move, when the struct implements Drop.
struct B;
struct S<K> { a: isize, b: B, c: K }
impl<K> Drop for S<K> { fn drop(&mut self) { } }
struct T { a: isize, b: Box<isize> }
impl Drop for T { fn drop(&mut self) { } }
struct V<K> { a: isize, b: Box<isize>, c: K }
impl<K> Drop for V<K> { fn drop(&mut self) { } }
#[derive(Clone)]
struct Clonable;
mod not_all_clone {
use super::*;
fn a(s0: S<()>) {
let _s2 = S { a: 2, ..s0 };
//~^ ERROR [E0509]
}
fn b(s0: S<B>) {
let _s2 = S { a: 2, ..s0 };
//~^ ERROR [E0509]
//~| ERROR [E0509]
}
fn c<K: Clone>(s0: S<K>) {
let _s2 = S { a: 2, ..s0 };
//~^ ERROR [E0509]
//~| ERROR [E0509]
}
}
mod all_clone {
use super::*;
fn a(s0: T) {
let _s2 = T { a: 2, ..s0 };
//~^ ERROR [E0509]
}
fn b(s0: T) {
let _s2 = T { ..s0 };
//~^ ERROR [E0509]
}
fn c(s0: T) {
let _s2 = T { a: 2, b: s0.b };
//~^ ERROR [E0509]
}
fn d<K: Clone>(s0: V<K>) {
let _s2 = V { a: 2, ..s0 };
//~^ ERROR [E0509]
//~| ERROR [E0509]
}
fn e(s0: V<Clonable>) {
let _s2 = V { a: 2, ..s0 };
//~^ ERROR [E0509]
//~| ERROR [E0509]
}
}
fn main() { }