rust/tests/ui/foreign-fn-return-lifetime.rs
Esteban Küber b7a23bc08b On borrow return type, suggest borrowing from arg or owned return type
When we encounter a function with a return type that has an anonymous
lifetime with no argument to borrow from, besides suggesting the
`'static` lifetime we now also suggest changing the arguments to be
borrows or changing the return type to be an owned type.

```
error[E0106]: missing lifetime specifier
  --> $DIR/variadic-ffi-6.rs:7:6
   |
LL | ) -> &usize {
   |      ^ expected named lifetime parameter
   |
   = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
   |
LL | ) -> &'static usize {
   |       +++++++
help: instead, you are more likely to want to change one of the arguments to be borrowed...
   |
LL |     x: &usize,
   |        +
help: ...or alternatively, to want to return an owned value
   |
LL - ) -> &usize {
LL + ) -> usize {
   |
```

Fix #85843.
2023-11-20 23:44:36 +00:00

7 lines
124 B
Rust

extern "C" {
pub fn g(_: &u8) -> &u8; // OK
pub fn f() -> &u8; //~ ERROR missing lifetime specifier
}
fn main() {}