error: `&'static str` is forbidden as the type of a const generic parameter --> $DIR/feature-gate-adt_const_params.rs:1:24 | LL | struct Foo; | ^^^^^^^^^^^^ | = 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