error[E0277]: the size for values of type `[u8]` cannot be known at compilation time --> $DIR/wf-bounds.rs:13:22 | LL | fn nya() -> impl Wf>; | ^^^^^^^^^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `[u8]` note: required by a bound in `Vec` --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL error[E0277]: the size for values of type `[u8]` cannot be known at compilation time --> $DIR/wf-bounds.rs:16:23 | LL | fn nya2() -> impl Wf<[u8]>; | ^^^^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `[u8]` note: required by a bound in `Wf` --> $DIR/wf-bounds.rs:8:10 | LL | trait Wf { | ^ required by this bound in `Wf` help: consider relaxing the implicit `Sized` restriction | LL | trait Wf { | ++++++++ error[E0277]: the size for values of type `[u8]` cannot be known at compilation time --> $DIR/wf-bounds.rs:19:44 | LL | fn nya3() -> impl Wf<(), Output = impl Wf>>; | ^^^^^^^^^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `[u8]` note: required by a bound in `Vec` --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0277`.