error: the trait `X` cannot be made into an object --> $DIR/issue-50781.rs:6:8 | LL | fn foo(&self) where Self: Trait; | ^^^ | = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #51443 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 --> $DIR/issue-50781.rs:6:8 | LL | trait X { | - this trait cannot be made into an object... LL | fn foo(&self) where Self: Trait; | ^^^ ...because method `foo` references the `Self` type in its `where` clause = help: consider moving `foo` to another trait note: the lint level is defined here --> $DIR/issue-50781.rs:1:9 | LL | #![deny(where_clauses_object_safety)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 1 previous error