error[E0277]: the trait bound `Cell<()>: ShallowCopy` is not satisfied
 --> $DIR/lib.rs:7:2
  |
7 |     f2: std::cell::Cell<()>,
  |     ^^ the trait `ShallowCopy` is not implemented for `Cell<()>`
  |
  = note: required by `shallow_copy`

error[E0277]: the trait bound `Cell<()>: ShallowCopy` is not satisfied
  --> $DIR/lib.rs:10:10
   |
10 | #[derive(ShallowCopy)]
   |          ^^^^^^^^^^^ the trait `ShallowCopy` is not implemented for `Cell<()>`
   |
   = note: required by `shallow_copy`
   = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0599]: no method named `shallow_copy` found for struct `Generic<Cell<()>>` in the current scope
   --> $DIR/lib.rs:24:10
    |
14  | struct Generic<T> {
    | -----------------
    | |
    | method `shallow_copy` not found for this
    | doesn't satisfy `Generic<Cell<()>>: ShallowCopy`
...
24  |     generic.shallow_copy();
    |             ^^^^^^^^^^^^ method not found in `Generic<Cell<()>>`
    |
   ::: $RUST/core/src/cell.rs
    |
    | pub struct Cell<T: ?Sized> {
    | -------------------------- doesn't satisfy `Cell<()>: ShallowCopy`
    |
   ::: $WORKSPACE/evmap/src/shallow_copy.rs
    |
    |     unsafe fn shallow_copy(&self) -> ManuallyDrop<Self>;
    |               ------------
    |               |
    |               the method is available for `Box<Generic<Cell<()>>>` here
    |               the method is available for `Arc<Generic<Cell<()>>>` here
    |               the method is available for `Rc<Generic<Cell<()>>>` here
    |
    = note: the method `shallow_copy` exists but the following trait bounds were not satisfied:
            `Cell<()>: ShallowCopy`
            which is required by `Generic<Cell<()>>: ShallowCopy`
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `shallow_copy`, perhaps you need to implement it:
            candidate #1: `ShallowCopy`