error: at least one trait must be specified
  --> $DIR/issue-86719.rs:7:14
   |
LL |     type E = impl ;
   |              ^^^^

error[E0407]: method `foo` is not a member of trait `Bar`
  --> $DIR/issue-86719.rs:8:5
   |
LL | /     fn foo() -> Self::E {
LL | |
LL | |         |_| true
LL | |     }
   | |_____^ not a member of trait `Bar`

error[E0282]: type annotations needed
  --> $DIR/issue-86719.rs:10:10
   |
LL |         |_| true
   |          ^
   |
help: consider giving this closure parameter an explicit type
   |
LL |         |_: /* Type */| true
   |           ++++++++++++

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0282, E0407.
For more information about an error, try `rustc --explain E0282`.