src/test/ui/unsized/unsized-enum.stderr

   1 error[E0277]: the size for values of type `T` cannot be known at compilation time
   2   --> $DIR/unsized-enum.rs:6:36
   3    |
   4 LL | enum Foo<U> { FooSome(U), FooNone }
   5    |          - required by this bound in `Foo`
   6 LL | fn foo1<T>() { not_sized::<Foo<T>>() } // Hunky dory.
   7 LL | fn foo2<T: ?Sized>() { not_sized::<Foo<T>>() }
   8    |         -                          ^^^^^^ doesn't have a size known at compile-time
   9    |         |
  10    |         this type parameter needs to be `Sized`
  11    |
  12 help: you could relax the implicit `Sized` bound on `U` if it were used through indirection like `&U` or `Box<U>`
  13   --> $DIR/unsized-enum.rs:4:10
  14    |
  15 LL | enum Foo<U> { FooSome(U), FooNone }
  16    |          ^            - ...if indirection were used here: `Box<U>`
  17    |          |
  18    |          this could be changed to `U: ?Sized`...
  19
  20 error: aborting due to previous error
  21
  22 For more information about this error, try `rustc --explain E0277`.