1 error[E0277]: the size for values of type `X` cannot be known at compilation time
2 --> $DIR/unsized-trait-impl-trait-arg.rs:8:17
4 LL | impl<X: ?Sized> T2<X> for S4<X> {
5 | - ^^^^^ doesn't have a size known at compile-time
7 | this type parameter needs to be `std::marker::Sized`
9 note: required by a bound in `T2`
10 --> $DIR/unsized-trait-impl-trait-arg.rs:4:10
13 | ^ required by this bound in `T2`
14 help: consider removing the `?Sized` bound to make the type parameter `Sized`
16 LL - impl<X: ?Sized> T2<X> for S4<X> {
17 LL + impl<X> T2<X> for S4<X> {
19 help: consider relaxing the implicit `Sized` restriction
21 LL | trait T2<Z: ?Sized> {
24 error: aborting due to previous error
26 For more information about this error, try `rustc --explain E0277`.