error[E0277]: the size for values of type `[bool]` cannot be known at compilation time --> $DIR/invalid-unsized-in-always-sized-tail.rs:11:8 | LL | b: MySliceBool, | ^^^^^^^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `[bool]` note: required by an implicit `Sized` bound in `MySlice` --> $DIR/invalid-unsized-in-always-sized-tail.rs:7:16 | LL | struct MySlice(T); | ^ required by the implicit `Sized` requirement on this type parameter in `MySlice` help: you could relax the implicit `Sized` bound on `T` if it were used through indirection like `&T` or `Box` --> $DIR/invalid-unsized-in-always-sized-tail.rs:7:16 | LL | struct MySlice(T); | ^ - ...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`.