Cielonos/Assets/Scripts/SLSUtilities/General/Singleton.cs

using Sirenix.OdinInspector;
using UnityEngine;

namespace SLSUtilities.General
{
    public class Singleton<T> : SerializedMonoBehaviour where T : MonoBehaviour
    {
        protected static T instance;
        public static T Instance => instance == null ? FindFirstObjectByType<T>() : instance;

        protected virtual void Awake()
        {
            Initialize(false);
        }

        protected virtual void Initialize(bool dontDestroy)
        {
            if (dontDestroy)
            {
                if (instance == null)
                {
                    instance = this as T;
                    DontDestroyOnLoad(gameObject);
                }
                else
                {
                    Destroy(gameObject);
                }
            }
            else
            {
                instance = this as T;
            }
        }
    }
}