In google/zerocopy#171 (comment), we're adding the ability to safely convert between byte slices/arrays and raw pointers. Currently, we have a test that is successfully failing if we try to perform this operation in a const context. What I want to know is: Is it guaranteed that code that performs any such conversion in a const context will always be rejected, or is this a best-effort analysis? If it's the former, then we can soundly emit the trait impls proposed in that PR, but if not, those impls would be unsound.