1error[E0038]: the trait `Foo` cannot be made into an object 2 --> $DIR/gat-in-trait-path.rs:21:17 3 | 4LL | fn f(_arg : Box<dyn for<'a> Foo<A<'a> = &'a ()>>) {} 5 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Foo` cannot be made into an object 6 | 7note: 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/gat-in-trait-path.rs:5:10 9 | 10LL | trait Foo { 11 | --- this trait cannot be made into an object... 12LL | type A<'a> where Self: 'a; 13 | ^ ...because it contains the generic associated type `A` 14 = help: consider moving `A` to another trait 15 16error: aborting due to previous error 17 18For more information about this error, try `rustc --explain E0038`. 19