> On the downside, it's support for safe (in the sense that the compiler checks it) lock free programming is basically non-existent, which means that stuff that would be easy in C++ ends up being in Rust unsafe blocks that you need a PhD in type theory to reason about.

I'm not familiar with the C++ built-in facilities for lock-free stuff (but learning about them currently)

Could you expand on this if you're willing, maybe with some pseudocode?

I've also been curious about things like cache alignment, aligned memory, and false-sharing size detection in Rust -- all of which C++ has as std built-ins