The challenge of first-class memory

Sounds like memory regions in Nim[1]

  type
    Memory[T] = object
      len: int
      data: ptr UncheckedArray[T]
  
    Kernel = object
    Userspace = object
  
  
  var a: Kernel ptr Memory[int]
  var b: Userspace ptr Memory[int]


  a = b # type mismatch: got (ptr[Userspace, Memory[system.int]]) but expected 'ptr[Kernel, Memory[system.int]]'

You can even change the GC to region-based memory management [2].

[1]: https://nim-lang.org/docs/manual.html#types-memory-regions

[2]: https://en.m.wikipedia.org/wiki/Region-based_memory_manageme...

You mean program in C?