We have to manually ensure that, *if* our inputs are const-valid, then we will not trigger a CTFE error and return a const-valid result.
For this example, the reason no CTFE error can arise is that references cannot dangle.
We can thus provide `ptr_eq` as an abstraction that is entirely safe to use in const context, even though it contains a potentially const-unsafe operation.
We have to manually ensure that, *if* our inputs are const-valid, then we will not trigger a CTFE error and return a const-valid result.
For this example, the reason no CTFE error can arise is that references cannot dangle.
We can thus provide `ptr_eq` as an abstraction that is entirely safe to use in const context, even though it contains a potentially const-unsafe operation.