LL | struct Foo<T: ?Hash> { }
| ^ unused parameter
|
- = help: consider removing `T`, referring to it in a field, or using a marker such as `std::marker::PhantomData`
+ = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`
error: aborting due to 2 previous errors; 1 warning emitted