Question

The C# scripting environement in Unity3D (runned under Mono) has a nice behavior when detroying objects. All the references that point to the destroyed object gets automaticly null :

    GameObject ref1 = (GameObject)Instantiate(obj);
    GameObject ref2 = ref1;

    if (ref1 != null)
        Debug.Log("ref1 is not null");

    DestroyImmediate(ref1);

    if (ref1 == null)
        Debug.Log("ref1 is null");

    if (ref2 == null)
        Debug.Log("ref2 is null");    

Output :

    ref1 is not null
    ref1 is null
    ref2 is null

Any ideas on how to acheive this ?

Thanks

Answer 1

It is possible that Unity3D (ab)uses operator overloading + some a kind of internal flag like bool isDeleted; so that when isDeleted is set to true in the DestroyImmediate function then the equality test against null yields true.