error[E0080]: evaluation of constant value failed
  --> $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL
   |
   = note: the evaluated program panicked at 'null-ness of this pointer cannot be determined in const context', $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL
   |
note: inside `std::ptr::const_ptr::<impl *const T>::is_null::compiletime`
  --> $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL
note: inside `std::ptr::const_ptr::<impl *const i32>::is_null`
  --> $SRC_DIR/core/src/ptr/const_ptr.rs:LL:COL
note: inside `MAYBE_NULL`
  --> $DIR/const-ptr-is-null.rs:17:14
   |
LL |     assert!(!ptr.wrapping_sub(512).is_null());
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = note: this error originates in the macro `$crate::panic::panic_2021` which comes from the expansion of the macro `const_eval_select` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0080`.