| error[E0658]: yield syntax is experimental | 
 |   --> $DIR/feature-gate-yield-expr.rs:5:5 | 
 |    | | 
 | LL |     yield (); | 
 |    |     ^^^^^^^^ | 
 |    | | 
 |    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information | 
 |    = help: add `#![feature(yield_expr)]` to the crate attributes to enable | 
 |    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date | 
 |  | 
 | error[E0658]: yield syntax is experimental | 
 |   --> $DIR/feature-gate-yield-expr.rs:5:5 | 
 |    | | 
 | LL |     yield (); | 
 |    |     ^^^^^^^^ | 
 |    | | 
 |    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information | 
 |    = help: add `#![feature(yield_expr)]` to the crate attributes to enable | 
 |    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date | 
 |  | 
 | error: `yield` can only be used in `#[coroutine]` closures, or `gen` blocks | 
 |   --> $DIR/feature-gate-yield-expr.rs:5:5 | 
 |    | | 
 | LL |     yield (); | 
 |    |     ^^^^^^^^ | 
 |    | | 
 | help: use `#[coroutine]` to make this closure a coroutine | 
 |    | | 
 | LL | #[coroutine] fn main() { | 
 |    | ++++++++++++ | 
 |  | 
 | error[E0627]: yield expression outside of coroutine literal | 
 |   --> $DIR/feature-gate-yield-expr.rs:5:5 | 
 |    | | 
 | LL |     yield (); | 
 |    |     ^^^^^^^^ | 
 |  | 
 | error: aborting due to 4 previous errors | 
 |  | 
 | Some errors have detailed explanations: E0627, E0658. | 
 | For more information about an error, try `rustc --explain E0627`. |