Used to sync a referemce to a NetworkIdentity without requiring the object to be spawned when the reference was sent

Example.md

NetworkIdentityReference can be used for synclists

public class MyBehaviour : NetworkBehaviour
{
    public SyncList<NetworkIdentityReference> others = new SyncList<NetworkIdentityReference>();

    public override void OnStartClient()
    {
        foreach (NetworkIdentity other in others)
        {
            Debug.Log($"this {netId} other {other?.netId}");
        }
    }
}

spawn and add references

NetIdRef clone1 = Instantiate(prefabWithNetIdRef);
NetIdRef clone2 = Instantiate(prefabWithNetIdRef);

NetworkServer.Spawn(clone1.gameObject);
NetworkServer.Spawn(clone2.gameObject);

// reference each other
clone1.others.Add(clone2.netIdentity);
clone2.others.Add(clone1.netIdentity);

NetworkIdentityReference.cs

namespace Mirror
{
    public struct NetworkIdentityReference
    {
        public uint netid;

        NetworkIdentity _identity;

        public NetworkIdentityReference(NetworkIdentity identity) : this()
        {
            Identity = identity;
        }

        public NetworkIdentity Identity
        {
            get
            {
                return NetworkServer.active
                    ? _identity
                    : NetworkIdentity.spawned[netid];
            }

            set
            {
                _identity = value;

                netid = value != null
                    ? value.netId
                    : 0;
            }
        }

        public static implicit operator NetworkIdentity(NetworkIdentityReference identityRef) => identityRef.Identity;
        public static implicit operator NetworkIdentityReference(NetworkIdentity identity) => new NetworkIdentityReference(identity);
    }
}