error[E0658]: casting pointers to integers in constants is unstable (see issue #51910) --> $DIR/match-test-ptr-null.rs:6:15 | LL | match &1 as *const i32 as usize { //~ ERROR casting pointers to integers in constants | ^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: add #![feature(const_raw_ptr_to_usize_cast)] to the crate attributes to enable error[E0019]: constant contains unimplemented expression type --> $DIR/match-test-ptr-null.rs:7:13 | LL | 0 => 42, //~ ERROR constant contains unimplemented expression type | ^ error[E0080]: evaluation of constant value failed --> $DIR/match-test-ptr-null.rs:7:13 | LL | 0 => 42, //~ ERROR constant contains unimplemented expression type | ^ "pointer arithmetic or comparison" needs an rfc before being allowed inside constants error: aborting due to 3 previous errors Some errors occurred: E0019, E0080, E0658. For more information about an error, try `rustc --explain E0019`.