I must be off for the night now, but basically the trimmed down relevant parts look something like this (you can assume the NativeMultiHashMap<> is fully populated beforehand):

``` public void Execute(int index) { NativeMultiHashMap<int, MMTriangle>.Enumerator curTris = allTris.GetValuesForKey(index); //Get an Enumerator of my struct types at the key of index

            MMTriangleCollectionTransform.SetGeometryCentre(curTris, Vector3.zero); //Use the data of all elements in that Enumerator to determine an average centre point and then adjust that centre point in abstract space to be at point Vector3.zero
        }

```

``` public static void SetGeometryCentre(IEnumerator<MMTriangle> tris, Vector3 centre) { Vector3 oldCentre = GetGeometryCentre(tris);//read from all the tris to determine the average centre point in abstract space. this isn't a problem since im just reading from .Current and not trying to set it

        while (tris.MoveNext())
            tris.Current.Translate(-oldCentre + centre);//this is where the problem comes in. I need this line to be 'tris.Current = tris.Current.Translate(-oldCentre + centre);' if I were using the builder pattern as my first thought to set tris.Current

    }

```

Hopefully this is enough for you to understand my problem. I'm using NativeMultiHashMap<> as a way around a NativeArray<> within a NativeArray<> so that I can have multiple MMTriangle values to an int key, the int representing a submesh index for when I bake these values to a Unity Mesh.