Second class pointers

[Nicholas Wilson via Digitalmars-d-learn]

So as part of my effort to get D running on GPUs I need to make a 
"second class" pointer type that I can alter in the backend of 
LDC to the correct address space. to that end I have made the 
following

module dcompute.types.pointer;

enum Private = 0;
enum Global = 1;
enum Shared = 2;
enum Constant = 3;
enum Generic = 4;

pure @trusted nothrow @nogc
struct Pointer(uint p, T) if(p <= Generic)
{
     T* ptr;
     ref T opUnary(string op)() if(op=="*")
     {
         return *ptr;
     }
     ref T opIndex(size_t i)
     {
         return *(ptr+i);
     }
     auto opBinary(string op)(ptrdiff_t i) if(op=="+" || op == "-")
     {
          return Pointer!(p, T) (ptr + i);
     }
}

is there anything else that I'm missing that you can do with a 
raw pointer?