| error[E0277]: the size for values of type `X` cannot be known at compilation time |
| --> $DIR/unsized-trait-impl-trait-arg.rs:8:17 |
| | |
| LL | impl<X: ?Sized> T2<X> for S4<X> { |
| | - ^^^^^ doesn't have a size known at compile-time |
| | | |
| | this type parameter needs to be `std::marker::Sized` |
| | |
| = help: the trait `std::marker::Sized` is not implemented for `X` |
| = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait> |
| |
| error: aborting due to previous error |
| |
| For more information about this error, try `rustc --explain E0277`. |