Pointers Are Complicated, or: What's in a Byte? rpds: Rust Persistent Data Structures v0.5.0 - Now with fast mutable methods

Thoughts on Compile-Time Function Evaluation and Type Systems

For some time now (since the 1.26 release, to be precise), Rust has a very powerful machinery for CTFE, or compile-time function evaluation. Since then, there have been various discussions about which operations should be allowed during CTFE, which checks the compiler should do, how this all relates to promotion and which kinds of guarantees we should be able to expect around CTFE. This post is my take on those topics, and it should not be surprising that I am going to take a very type-system centric view. Expect something like a structured brain dump, so there are some unanswered questions towards the end as well.