Louis Ingenthron @LouisIngenthron@social.cleverlibre.org

@leclau @maxkennerly Competent employees? Office space that's actually paid for? Someone competent to run the show? All unnecessary luxuries for a multi-billion dollar tech company.

@maxkennerly "before we have the luxury of anything else" he says, as he chooses to hemorrhage additional money to paying thousands to some of the most despicable users of his free platform.

@annmlipton Wait, those are different groups?

@peterdrake It shouldn't, so long as unity's implementation of (Singleton == this) has its own null-check first, which it probably does, but I'm not sure.
So, the situation I'm concerned about would be that Singleton references a destroyed object. Running (Singleton == null) checks if it's null *or* destroyed, which prevents the second check. But I don't know if (Singleton == this) will also break out if it's null or if it will try to run a comparison op between a live object and a destroyed one (which would throw an error).

In other words, it's mostly just me being paranoid and defensively coding.

@peterdrake No, I don't think so. It would only be to check if a singleton from a previous execution context was still stored in the static reference.

But it's worth noting that there are a number of places where OnDestroy may *not* be called (mostly in-editor, not in-built-game, such as hard exits).

@peterdrake On 1, correct. That's why I usually make the singleton property a public get but a private set. With the pattern above, that achieves the same goals.

On 2, it's to specifically use Unity's overloaded null checks to make sure it's not pointing to a dead/destroyed reference before checking equality. I'm not sure if the straight equality check does that, so I added a null check as a short-circuit.

@freemo That seems like a far more consistent position.

@peterdrake Basically, the key is to make sure to clean up after yourself since the editor won't do it for you. So, if you have a static score integer, make sure somebody's start function resets it to zero. Stuff like that.

@peterdrake Oh, you still have to use statics, you just have to be smart about it. This is the pattern I use that hasn't failed yet. Put it in the Start() function of MonoBehaviours. Try to avoid singletons of non-unity-managed-objects (you'd need a different pattern than the below).

if(Singleton == null)
{
Singleton = this;
DontDestroyOnLoad(gameObject);
}
else if(Singleton != this)
{
Destroy(gameObject); // two in scene
}

As long as you do that for Unity objects, that first null check will use Unity's override == check to also check for destroyed or unreferenceable objects.

And then in the Destroy function:

if(Singleton != null && Singleton == this)
{
Singleton = null;
}