Tracking allocations is necessary, but not sufficient.

  struct S {
    int arr1[100];
    std::string s;
    int arr2[100];
  };

  void foo(S& s) {
    //arr1 and arr2 are in the same complete object
    //so they are in the same allocation
    std::sort(std::begin(arr1), std::end(arr2));
  }

To make it sound you really need to track arrays specifically (including implicit single-element ones), not just allocations.

It's surely somewhat feasible, as the constexpr interpreters in compilers do track it, but something like that would probably be way inefficient at runtime.