error[E0277]: the trait bound `(): const Foo` is not satisfied
  --> $DIR/const-opaque.rs:31:22
   |
LL |     let opaque = bar(());
   |                  --- ^^
   |                  |
   |                  required by a bound introduced by this call
   |
note: required by a bound in `bar`
  --> $DIR/const-opaque.rs:26:17
   |
LL | const fn bar<T: ~const Foo>(t: T) -> impl ~const Foo {
   |                 ^^^^^^ required by this bound in `bar`

error[E0277]: the trait bound `(): const Foo` is not satisfied
  --> $DIR/const-opaque.rs:33:12
   |
LL |     opaque.method();
   |            ^^^^^^

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0277`.