error[E0277]: the size for values of type `X` cannot be known at compilation time
--> $DIR/unsized7.rs:12:21
|
+LL | trait T1<Z: T> {
+ | - required by this bound in `T1`
+...
LL | impl<X: ?Sized + T> T1<X> for S3<X> {
| - ^^^^^ doesn't have a size known at compile-time
| |