What does GeMarker do?

On 05/12/2013 at 08:21, xxxxxxxx wrote:

User Information:
Cinema 4D Version:   13 
Language(s) :     C++  ;

I'm trying to figure out just what the heck the GeMarker class does.
The results I'm getting aren't  making any sense to me.

In this test. I create two of the same objects(two cubes, two spheres, etc..).
Then run the code below to compare their markers

    BaseObject *obj = doc->GetFirstObject();  
  if(!obj) return FALSE;  
  BaseObject *next = obj->GetNext();  
  if(!obj) return FALSE;  
  const GeMarker &objM = obj->GetMarker();  
  const GeMarker &nextM = next->GetMarker();  
  //Check if the markers have content in them  
  Bool objEmpty = objM.Content();  
  Bool nextEmpty = nextM.Content();  
  //Check if the two markers are equal  
  Bool eql = objM.IsEqual(nextM);  
  GePrint("obj&next Markers Equal? = " + LongToString(eql));  
  //Compare the two markers(works like memcmp)  
  LONG comp = objM.Compare(nextM);  
  GePrint("Compare the obj&next Markers = " + LongToString(comp));

The result of this code is that no two objects are ever "equal". Which I think I understand.
But the results of the Compare() function are sometimes true, and sometimes false!?
What is it about certain objects that makes them return different true or false results like that?

//None of these are "equal"  
//However...When using the Compare() function on them. Some are true and some are false! Why?  
//Cylinder   compare = true  
//Disc       compare = true  
//Plane      compare = true  
//polygon    compare = true  
//Oil Tank   compare = true  
//Cone       compare = false  
//Cube       compare = false  
//Capsule    compare = false  
//Figure     compare = false  
//Landscape  compare = false  
//Platonic   compare = false  
//Pyramid    compare = false  
//Relief     compare = false  
//Sphere     compare = false  
//Torus      compare = false  
//Tube       compare = false

To make two objects return true using IsEqual() function.
The only way I can do it is by creating a brand new marker. Then setting it to the same marker value of another object.

    //Create a new empty marker from scratch  
  AutoAlloc<GeMarker> myMarker;  
  //Make the new marker the same as the objM marker  
  Bool eql2 = objM.IsEqual(myMarker);  
  LONG comp2 = objM.Compare(nextM);  
  GePrint("New Marker Equal to obj Marker? = " + LongToString(eql2));  
  GePrint("New Marker Compare = " + LongToString(comp2));

Is there any way to make two objects have the same marker value without creating a new one from scratch?

Why do I even care about these markers?
What purpose do they serve in the grand scheme of things?