error[E0560]: struct `NonCopyable` has no field named `p`
  --> $DIR/issue-4736.rs:4:26
   |
LL | struct NonCopyable(());
   |        ----------- `NonCopyable` defined here
...
LL |     let z = NonCopyable{ p: () };
   |                          ^ field does not exist
   |
help: `NonCopyable` is a tuple struct, use the appropriate syntax
   |
LL |     let z = NonCopyable(/* fields */);
   |             ~~~~~~~~~~~~~~~~~~~~~~~~~

error: aborting due to previous error

For more information about this error, try `rustc --explain E0560`.