error[E0597]: `a` does not live long enough
  --> $DIR/borrowing.rs:9:33
   |
LL |     let _b = {
   |         -- borrow later stored here
LL |         let a = 3;
LL |         Pin::new(&mut || yield &a).resume(())
   |                       --        ^ borrowed value does not live long enough
   |                       |
   |                       value captured here by coroutine
LL |
LL |     };
   |     - `a` dropped here while still borrowed

error[E0597]: `a` does not live long enough
  --> $DIR/borrowing.rs:16:20
   |
LL |     let _b = {
   |         -- borrow later stored here
LL |         let a = 3;
LL |         || {
   |         -- value captured here by coroutine
LL |             yield &a
   |                    ^ borrowed value does not live long enough
...
LL |     };
   |     - `a` dropped here while still borrowed

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0597`.