error[E0392]: parameter `T` is never used
  --> $DIR/E0392.rs:1:10
   |
LL | enum Foo<T> { Bar }
   |          ^ unused parameter
   |
   = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`
   = help: if you intended `T` to be a const parameter, use `const T: usize` instead

error: aborting due to previous error

For more information about this error, try `rustc --explain E0392`.