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