error: `&'static (dyn A + 'static)` is forbidden as the type of a const generic parameter --> $DIR/issue-63322-forbid-dyn.rs:9:18 | LL | fn test() { | ^^^^^^^^^^^^^^ | = note: the only supported types are integers, `bool` and `char` = help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types error: aborting due to previous error