error[E0277]: the size for values of type `[u8]` cannot be known at compilation time --> $DIR/issue-85943-no-suggest-unsized-indirection-in-where-clause.rs:5:10 | LL | struct B(A<[u8]>); | ^^^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `[u8]` note: required by an implicit `Sized` bound in `A` --> $DIR/issue-85943-no-suggest-unsized-indirection-in-where-clause.rs:4:10 | LL | struct A(T) where T: Send; | ^ required by the implicit `Sized` requirement on this type parameter in `A` help: you could relax the implicit `Sized` bound on `T` if it were used through indirection like `&T` or `Box` --> $DIR/issue-85943-no-suggest-unsized-indirection-in-where-clause.rs:4:10 | LL | struct A(T) where T: Send; | ^ - ...if indirection were used here: `Box` | | | this could be changed to `T: ?Sized`... error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.