error[E0658]: yield syntax is experimental
 --> tests/ui/yield_in_closure.rs:7:17
  |
7 |                 yield v;
  |                 ^^^^^^^
  |
  = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information

error: `yield` can only be used in `#[coroutine]` closures, or `gen` blocks
 --> tests/ui/yield_in_closure.rs:7:17
  |
7 |                 yield v;
  |                 ^^^^^^^
  |
help: use `#[coroutine]` to make this closure a coroutine
  |
6 |             .and_then(#[coroutine] |v| {
  |                       ++++++++++++

error[E0277]: expected a `FnOnce(&str)` closure, found `{coroutine@$DIR/tests/ui/yield_in_closure.rs:6:23: 6:26}`
 --> tests/ui/yield_in_closure.rs:6:23
  |
6 |               .and_then(|v| {
  |  ______________--------_^
  | |              |
  | |              required by a bound introduced by this call
7 | |                 yield v;
8 | |                 Ok(())
9 | |             });
  | |_____________^ expected an `FnOnce(&str)` closure, found `{coroutine@$DIR/tests/ui/yield_in_closure.rs:6:23: 6:26}`
  |
  = help: the trait `FnOnce(&str)` is not implemented for `{coroutine@$DIR/tests/ui/yield_in_closure.rs:6:23: 6:26}`
note: required by a bound in `Result::<T, E>::and_then`
 --> $RUST/core/src/result.rs
  |
  |     pub fn and_then<U, F: FnOnce(T) -> Result<U, E>>(self, op: F) -> Result<U, E> {
  |                           ^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `Result::<T, E>::and_then`