§ 28.3 Pointers and the Garbage Collector

[kdevel via Digitalmars-d-learn]

In § 28.3 Pointers and the Garbage Collector [1] we read
   Do not add or subtract an offset to a pointer such that the 
result points
   outside of the bounds of the garbage collected object 
originally allocated.

      char* p = new char[10];
      char* q = p + 6; // ok
      q = p + 11;      // error: undefined behavior
      q = p - 1;       // error: undefined behavior

C and C++ allow a pointer to point to the (non-existing) element 
after the end
of the array:

   char *e = p + 10;

Does this point "outside of the bounds of the garbage collected 
object"?

In § 28.3 we also read

   Do not depend on the ordering of pointers:

      if (p1 < p2)  // error: undefined behavior
         ...

   since, again, the garbage collector can move objects around in 
memory.

In C and C++ we are used to read code like this:

   void foo ()
   {
      char *p = new char [10];
      char *e = p + 10;
      char *q;
      for (q = p; q < e; ++q)
         ...
   }

Does this for-loop "depend on the ordering of pointers"?

[1] https://dlang.org/spec/garbage.html#pointers_and_gc