error[E0620]: cast to unsized type: `&[usize; 2]` as `[usize]` --> $DIR/issue-17441.rs:2:16 | LL | let _foo = &[1_usize, 2] as [usize]; | ^^^^^^^^^^^^^^^^^^^^^^^^ | help: consider casting to a reference instead | LL | let _foo = &[1_usize, 2] as &[usize]; | + error[E0620]: cast to unsized type: `Box` as `dyn Debug` --> $DIR/issue-17441.rs:5:16 | LL | let _bar = Box::new(1_usize) as dyn std::fmt::Debug; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | help: you can cast to a `Box` instead | LL | let _bar = Box::new(1_usize) as Box; | ++++ + error[E0620]: cast to unsized type: `usize` as `dyn Debug` --> $DIR/issue-17441.rs:8:16 | LL | let _baz = 1_usize as dyn std::fmt::Debug; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | help: consider using a box or reference as appropriate --> $DIR/issue-17441.rs:8:16 | LL | let _baz = 1_usize as dyn std::fmt::Debug; | ^^^^^^^ error[E0620]: cast to unsized type: `[usize; 2]` as `[usize]` --> $DIR/issue-17441.rs:11:17 | LL | let _quux = [1_usize, 2] as [usize]; | ^^^^^^^^^^^^^^^^^^^^^^^ | help: consider using a box or reference as appropriate --> $DIR/issue-17441.rs:11:17 | LL | let _quux = [1_usize, 2] as [usize]; | ^^^^^^^^^^^^ error: aborting due to 4 previous errors For more information about this error, try `rustc --explain E0620`.