rust/tests/ui/rfcs/rfc-2632-const-trait-impl/const-closure-trait-method-fail.stderr
Esteban Küber e6bd6c2044 Use parenthetical notation for Fn traits
Always use the `Fn(T) -> R` format when printing closure traits instead of `Fn<(T,), Output = R>`.

Fix #67100:

```
error[E0277]: expected a `Fn()` closure, found `F`
 --> file.rs:6:13
  |
6 |     call_fn(f)
  |     ------- ^ expected an `Fn()` closure, found `F`
  |     |
  |     required by a bound introduced by this call
  |
  = note: wrap the `F` in a closure with no arguments: `|| { /* code */ }`
note: required by a bound in `call_fn`
 --> file.rs:1:15
  |
1 | fn call_fn<F: Fn() -> ()>(f: &F) {
  |               ^^^^^^^^^^ required by this bound in `call_fn`
help: consider further restricting this bound
  |
5 | fn call_any<F: std::any::Any + Fn()>(f: &F) {
  |                              ++++++
```
2024-05-29 22:26:54 +00:00

26 lines
966 B
Plaintext

error: `~const` can only be applied to `#[const_trait]` traits
--> $DIR/const-closure-trait-method-fail.rs:14:39
|
LL | const fn need_const_closure<T: ~const FnOnce(()) -> i32>(x: T) -> i32 {
| ^^^^^^^^^^^^^^^^^
error[E0015]: cannot call non-const closure in constant functions
--> $DIR/const-closure-trait-method-fail.rs:15:5
|
LL | x(())
| ^^^^^
|
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: consider further restricting this bound
|
LL | const fn need_const_closure<T: ~const FnOnce(()) -> i32 + ~const FnOnce(())>(x: T) -> i32 {
| +++++++++++++++++++
help: add `#![feature(effects)]` to the crate attributes to enable
|
LL + #![feature(effects)]
|
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0015`.