error[E0277]: the trait bound `(): _Contains<&C>` is not satisfied
  --> $DIR/issue-85848.rs:24:5
   |
LL |     writes_to_specific_path(&cap);
   |     ^^^^^^^^^^^^^^^^^^^^^^^ the trait `_Contains<&C>` is not implemented for `()`
...
LL | fn writes_to_specific_path<C: Delegates<()>>(cap: &C) {}
   |                               ------------- required by this bound in `writes_to_specific_path`
   |
note: required because of the requirements on the impl of `Contains<(), true>` for `&C`
  --> $DIR/issue-85848.rs:21:12
   |
LL | impl<T, U> Contains<T, { contains::<T, U>() }> for U where T: _Contains<U> {}
   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^     ^
note: required because of the requirements on the impl of `Delegates<()>` for `&C`
  --> $DIR/issue-85848.rs:12:12
   |
LL | impl<T, U> Delegates<U> for T where T: Contains<U, true> {}
   |            ^^^^^^^^^^^^     ^

error: unconstrained generic constant
  --> $DIR/issue-85848.rs:24:5
   |
LL |     writes_to_specific_path(&cap);
   |     ^^^^^^^^^^^^^^^^^^^^^^^
...
LL | fn writes_to_specific_path<C: Delegates<()>>(cap: &C) {}
   |                               ------------- required by this bound in `writes_to_specific_path`
   |
   = help: try adding a `where` bound using this expression: `where [(); { contains::<T, U>() }]:`
note: required because of the requirements on the impl of `Contains<(), true>` for `&C`
  --> $DIR/issue-85848.rs:21:12
   |
LL | impl<T, U> Contains<T, { contains::<T, U>() }> for U where T: _Contains<U> {}
   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^     ^
note: required because of the requirements on the impl of `Delegates<()>` for `&C`
  --> $DIR/issue-85848.rs:12:12
   |
LL | impl<T, U> Delegates<U> for T where T: Contains<U, true> {}
   |            ^^^^^^^^^^^^     ^

error: aborting due to 2 previous errors

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