blob: ad55f40b5b6382703bffae17bf321c29d55439c7 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
--> $DIR/try-operator-on-main.rs:7:31
|
LL | / fn main() {
LL | | // error for a `Try` type on a non-`Try` fn
LL | | std::fs::File::open("foo")?;
| | ^ cannot use the `?` operator in a function that returns `()`
LL | |
... |
LL | | try_trait_generic::<()>();
LL | | }
| |_- this function should return `Result` or `Option` to accept `?`
|
= help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
error[E0277]: the `?` operator can only be applied to values that implement `Try`
--> $DIR/try-operator-on-main.rs:10:5
|
LL | ()?;
| ^^^ the `?` operator cannot be applied to type `()`
|
= help: the trait `Try` is not implemented for `()`
error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
--> $DIR/try-operator-on-main.rs:10:7
|
LL | / fn main() {
LL | | // error for a `Try` type on a non-`Try` fn
LL | | std::fs::File::open("foo")?;
LL | |
LL | | // a non-`Try` type on a non-`Try` fn
LL | | ()?;
| | ^ cannot use the `?` operator in a function that returns `()`
... |
LL | | try_trait_generic::<()>();
LL | | }
| |_- this function should return `Result` or `Option` to accept `?`
|
= help: the trait `FromResidual<_>` is not implemented for `()`
error[E0277]: the trait bound `(): Try` is not satisfied
--> $DIR/try-operator-on-main.rs:14:25
|
LL | try_trait_generic::<()>();
| ^^ the trait `Try` is not implemented for `()`
|
note: required by a bound in `try_trait_generic`
--> $DIR/try-operator-on-main.rs:17:25
|
LL | fn try_trait_generic<T: Try>() -> T {
| ^^^ required by this bound in `try_trait_generic`
error[E0277]: the `?` operator can only be applied to values that implement `Try`
--> $DIR/try-operator-on-main.rs:19:5
|
LL | ()?;
| ^^^ the `?` operator cannot be applied to type `()`
|
= help: the trait `Try` is not implemented for `()`
error: aborting due to 5 previous errors
For more information about this error, try `rustc --explain E0277`.
|