rust/tests/ui/variance/variance-issue-20533.rs
Esteban Küber a1a3abb08f When possible, suggest cloning the result of a call instead of an argument
```
error[E0505]: cannot move out of `a` because it is borrowed
  --> $DIR/variance-issue-20533.rs:28:14
   |
LL |         let a = AffineU32(1);
   |             - binding `a` declared here
LL |         let x = foo(&a);
   |                     -- borrow of `a` occurs here
LL |         drop(a);
   |              ^ move out of `a` occurs here
LL |         drop(x);
   |              - borrow later used here
   |
help: consider cloning the value if the performance cost is acceptable
   |
LL |         let x = foo(&a).clone();
   |                        ++++++++
```
2024-04-11 16:41:41 +00:00

62 lines
1.2 KiB
Rust

// Regression test for issue #20533. At some point, only 1 out of the
// 3 errors below were being reported.
use std::marker::PhantomData;
fn foo<'a, T>(_x: &'a T) -> PhantomData<&'a ()> {
PhantomData
}
struct Wrap<T>(T);
fn bar<'a, T>(_x: &'a T) -> Wrap<PhantomData<&'a ()>> {
Wrap(PhantomData)
}
struct Baked<'a>(PhantomData<&'a ()>);
fn baz<'a, T>(_x: &'a T) -> Baked<'a> {
Baked(PhantomData)
}
fn bat(x: &AffineU32) -> &u32 {
&x.0
}
struct AffineU32(u32);
#[derive(Clone)]
struct ClonableAffineU32(u32);
fn main() {
{
let a = AffineU32(1);
let x = foo(&a);
drop(a); //~ ERROR cannot move out of `a`
drop(x);
}
{
let a = AffineU32(1);
let x = bar(&a);
drop(a); //~ ERROR cannot move out of `a`
drop(x);
}
{
let a = AffineU32(1);
let x = baz(&a);
drop(a); //~ ERROR cannot move out of `a`
drop(x);
}
{
let a = AffineU32(1);
let x = bat(&a);
drop(a); //~ ERROR cannot move out of `a`
drop(x);
}
{
let a = ClonableAffineU32(1);
let x = foo(&a);
drop(a); //~ ERROR cannot move out of `a`
drop(x);
}
}