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

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 `()`
note: required by `from_residual`
  --> $SRC_DIR/core/src/ops/try_trait.rs:LL:COL
   |
LL |     fn from_residual(residual: R) -> Self;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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 `()`
note: required by `branch`
  --> $SRC_DIR/core/src/ops/try_trait.rs:LL:COL
   |
LL |     fn branch(self) -> ControlFlow<Self::Residual, Self::Output>;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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 `()`
note: required by `from_residual`
  --> $SRC_DIR/core/src/ops/try_trait.rs:LL:COL
   |
LL |     fn from_residual(residual: R) -> Self;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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 `()`
...
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 `()`
note: required by `branch`
  --> $SRC_DIR/core/src/ops/try_trait.rs:LL:COL
   |
LL |     fn branch(self) -> ControlFlow<Self::Residual, Self::Output>;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 5 previous errors

For more information about this error, try `rustc --explain E0277`.