MonoSingleton.cs

using UnityEngine;

public class MonoSingleton<T> : MonoBehaviour where T : MonoBehaviour
{
    private static T _sInstance;

    public static T Instance
    {
        get
        {
            if ((Object)(object)MonoSingleton<T>._sInstance != (Object)null)
            {
                return MonoSingleton<T>._sInstance;
            }
            MonoSingleton<T>._sInstance = (T)Object.FindObjectOfType(typeof(T));
            if (Object.FindObjectsOfType(typeof(T)).Length > 1)
            {
                Debug.LogError("[Singleton] Something went really wrong  - there should never be more than 1 singleton! Reopening the scene might fix it.");
                return MonoSingleton<T>._sInstance;
            }
            if ((Object)(object)MonoSingleton<T>._sInstance == (Object)null)
            {
                //GameObject gameObject = new GameObject();
                //MonoSingleton<T>._sInstance = gameObject.AddComponent<T>();
                //gameObject.name = "(singleton) " + typeof(T).ToString();
                //Object.DontDestroyOnLoad(gameObject);
                Debug.Log("[Singleton] An instance of " + typeof(T) + " is needed in the scene, so was NOT created with DontDestroyOnLoad.");
            }
            return MonoSingleton<T>._sInstance;
        }
    }
}