error[E0770]: the type of const parameters must not depend on other generic parameters --> $DIR/issue-56445-1.rs:9:26 | LL | struct Bug<'a, const S: &'a str>(PhantomData<&'a ()>); | ^^ the type must not depend on the parameter `'a` | = note: lifetime parameters may not be used in the type of const parameters error: `&str` is forbidden as the type of a const generic parameter --> $DIR/issue-56445-1.rs:9:25 | LL | struct Bug<'a, const S: &'a str>(PhantomData<&'a ()>); | ^^^^^^^ | = 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 | LL + #![feature(adt_const_params)] | error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0770`.