error[E0277]: the size for values of type `str` cannot be known at compilation time --> $DIR/issue-14366.rs:2:14 | LL | let _x = "test" as &dyn (::std::any::Any); | ^^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `str` = note: required for the cast from `&'static str` to `&(dyn Any + 'static)` help: consider borrowing the value, since `&&'static str` can be coerced into `&(dyn Any + 'static)` | LL | let _x = &"test" as &dyn (::std::any::Any); | + error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.