error[E0282]: type annotations needed
  --> $DIR/issue-65611.rs:59:13
   |
LL |     let x = buffer.last().unwrap().0.clone();
   |             ^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type for type parameter `T`

error[E0609]: no field `0` on type `&_`
  --> $DIR/issue-65611.rs:59:36
   |
LL |     let x = buffer.last().unwrap().0.clone();
   |                                    ^

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0282, E0609.
For more information about an error, try `rustc --explain E0282`.
