I would also strongly argue you can’t draw useful inferences from do_fib. To rephrase it another way. In how many contexts is std::expect insufficient? It’s ea

I would also strongly argue you can’t draw useful inferences from do_fib. To rephrase it another way. In how many contexts is std::expect insufficient? It’s easy to find places where nothing short of hand rolled SIMD is fast enough. You cannot draw useful inferences from those cases.