project-safe-transmute VS Rudra-PoC

Project "safe transmute"

In this case a simple From implementation or anything like that won't be different, even performance wise. For more complex cases there's project-safe-transmute, but that will still require you to annotate your structs in such a way that their layouts will be guaranteed to be compatible, which you're not currently doing.

You might also be interested in the project safe transmute, which might bring safe transmutes like these to stdlib in the future.

That's probably a job for the safe transmute project

One of the biggest notable examples is unsafe transmutes that could be safe. In fact there's a safe transmute working group trying to cover these cases. Just to give an example, if you have a #[repr(transparent)] newtype, it could be possible to safely transmute from a reference of an inner type to the type it wraps (for e.g. 1-tuple or 1-field structs), but doing that now presently requires unsafe.

Jokes aside, there is actually a work on going for making a subset of transmutes safe: https://github.com/rust-lang/project-safe-transmute

There's a link to every issue in their readme: https://github.com/sslab-gatech/Rudra-PoC