error: `[u8; { struct Foo; impl Foo { fn value() -> usize { N } } Foo::<17>::value() }]` is forbidden as the type of a const generic parameter --> $DIR/nested-type.rs:6:21 | LL | struct Foo; LL | | LL | | impl Foo { ... | LL | | LL | | }]>; | |__^ | = note: the only supported types are integers, `bool` and `char` = help: more complex types are supported with `#![feature(adt_const_params)]` error: aborting due to previous error