[throwaway7356]

> Yes, that would limit things, but with today’s 64-bit address spaces I think it could work reasonably well for many systems programming tasks.

As long as the systems programming tasks are strictly sequential, without threads, coroutines or signal handlers.

There is more to memory access than just out-of-bounds access which could be solved by just allocating every accessed memory page on demand as a slightly alteration of your variant.

[Someone]

Good points. As to signal handlers, I’m not aware of any language that fully supports them by making it impossible to call other than async-safe functions (https://man7.org/linux/man-pages/man7/signal-safety.7.html) from asynchrony signal handlers.