error[E0658]: casting pointers to integers in constants is unstable --> $DIR/match-test-ptr-null.rs:6:15 | LL | match &1 as *const i32 as usize { | ^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: see issue #51910 for more information = help: add `#![feature(const_raw_ptr_to_usize_cast)]` to the crate attributes to enable error[E0080]: evaluation of constant value failed --> $DIR/match-test-ptr-null.rs:6:15 | LL | match &1 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`.