error[E0658]: casting pointers to integers in constants is unstable --> $DIR/issue-52023-array-size-pointer-cast.rs:2:17 | LL | let _ = [0; (&0 as *const i32) as usize]; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: for more information, see https://github.com/rust-lang/rust/issues/51910 = help: add `#![feature(const_raw_ptr_to_usize_cast)]` to the crate attributes to enable error[E0080]: evaluation of constant value failed --> $DIR/issue-52023-array-size-pointer-cast.rs:2:17 | LL | let _ = [0; (&0 as *const i32) as usize]; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ "pointer-to-integer cast" needs an rfc before being allowed inside constants error: aborting due to 2 previous errors Some errors have detailed explanations: E0080, E0658. For more information about an error, try `rustc --explain E0080`.