error[E0605]: non-primitive cast: `&&[i32; 1]` as `&[_]`
  --> $DIR/issue-73886.rs:2:13
   |
LL |     let _ = &&[0] as &[_];
   |             ^^^^^^^^^^^^^ an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object
   |
   = note: casting reference expression `&&[0]` because `&` binds tighter than `as`

error[E0605]: non-primitive cast: `u32` as `Option<_>`
  --> $DIR/issue-73886.rs:4:13
   |
LL |     let _ = 7u32 as Option<_>;
   |             ^^^^^^^^^^^^^^^^^ an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object
   |
help: consider using the `From` trait instead
   |
LL -     let _ = 7u32 as Option<_>;
LL +     let _ = Option::<_>::from(7u32);
   |

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0605`.