1 error[E0038]: the trait `Expr` cannot be made into an object
2 --> $DIR/object-safety-issue-22040.rs:12:23
4 LL | elements: Vec<Box<dyn Expr + 'x>>,
5 | ^^^^^^^^^^^^^ `Expr` cannot be made into an object
7 note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
8 --> $DIR/object-safety-issue-22040.rs:5:21
10 LL | trait Expr: Debug + PartialEq {
11 | ---- ^^^^^^^^^ ...because it uses `Self` as a type parameter
13 | this trait cannot be made into an object...
15 error: aborting due to previous error
17 For more information about this error, try `rustc --explain E0038`.