src/test/ui/try-trait/try-operator-on-main.stderr

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