C# array of pointers

Question

I am currently trying to create an octree in Unity. I would like each node to have a list of pointers that point to the AABB's of the childnodes. The AABB's are a struct that looks like this:

    public struct ABB
    {
        public float size;

        public float centerX;
        public float centerY;
        public float centerZ;

        public ABB(float size, float centerX, float centerY, float centerZ)
        {
            this.size = size;
            
            this.centerX = centerX;
            this.centerY = centerY;
            this.centerZ = centerZ;
        }
    }

Each node contains a list of its children:

 public OctreeNode[] children = null;

I would like to use the AABB's of the children of the node in a bursted job, but the OctreeNodes themselves are a class, which is not supported by burst. Therefore, I would like to get the AABB's, but storing a copy of them for each node seems a bit redundant. Therefore, storing a pointer to the AABB's of the children seems like the best solution for me. However, I fail to understand how to do this in C#.

Currently, I have an array of pointers

public ABB*[] childBounds = null;

My question is, how do I fill this array with pointers?

Something like:

    if (children[0] == null)
    {
        children[0] = new OctreeNode(new ABB(childLength, nodeBounds.centerX + -quarter, nodeBounds.centerY + quarter, nodeBounds.centerZ + -quarter), this, rootSeed);
        childBounds[0] = children[0].nodeBounds;
    }

Gives me an error, essentially saying that

Cannot implicitly convert type AABB (children[0].nodeBounds) to AABB*

Could someone try to explain how to do this properly in C#?

Answer 1

Thanks to everyone in the comments who pointed me in the right direction.

Essentially, store the pointer in a temporary variable, and then assigned it in a fixed() statement, like so:

        fixed(ABB* boundsPtr = &children[0].nodeBounds)
        {
            childBounds[0] = boundsPtr;
        }