> it "just requires" you to flawlessly uphold memory access invariants manually across all possible concurrent states of your program.
Which, for certain kinds of programs, is trivially simple for e.g. "set value once during early initialization, then only read it". No, it's not thread-local. And even for "okay, maybe atomically update it once in a blue moon from one specific place in code" scenario is pretty easy to do locklessly.
Sure, and those use cases are just as easily supported by Rust, in a more principled manner that directly encodes the intent and resists misuse by people modifying the code later.
Which, for certain kinds of programs, is trivially simple for e.g. "set value once during early initialization, then only read it". No, it's not thread-local. And even for "okay, maybe atomically update it once in a blue moon from one specific place in code" scenario is pretty easy to do locklessly.