mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-25 08:13:41 +00:00
22 lines
901 B
Plaintext
22 lines
901 B
Plaintext
error[E0746]: return type cannot have an unboxed trait object
|
|
--> $DIR/box-instead-of-dyn-fn.rs:5:56
|
|
|
|
|
LL | fn print_on_or_the_other<'a>(a: i32, b: &'a String) -> dyn Fn() + 'a {
|
|
| ^^^^^^^^^^^^^ doesn't have a size known at compile-time
|
|
|
|
|
help: return an `impl Trait` instead of a `dyn Trait`, if all returned values are the same type
|
|
|
|
|
LL | fn print_on_or_the_other<'a>(a: i32, b: &'a String) -> impl Fn() + 'a {
|
|
| ~~~~
|
|
help: box the return type, and wrap all of the returned values in `Box::new`
|
|
|
|
|
LL ~ fn print_on_or_the_other<'a>(a: i32, b: &'a String) -> Box<dyn Fn() + 'a> {
|
|
LL |
|
|
LL | if a % 2 == 0 {
|
|
LL ~ Box::new(move || println!("{a}"))
|
|
|
|
|
|
|
error: aborting due to previous error
|
|
|
|
For more information about this error, try `rustc --explain E0746`.
|