GGJ_2019/Assets/Scipts/Utility/Singleton.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class MonoSingleton<T> : MonoBehaviour where T : MonoSingleton<T>
{

    public static T Instance { get; private set; }

    [Header("Singleton Settings")]
    public bool SetSingletonOnAwake;
    public bool isPersistant;

    protected virtual void Awake()
    {
        if (SetSingletonOnAwake)
            SetAsSingleton();
    }

    private void SetAsSingleton()
    {
        if (Instance != null && Instance != this)
            Destroy(this.gameObject);
        else
            Instance = (T)this;

        if (isPersistant)
            DontDestroyOnLoad(transform.root);
    }

}

public class Singleton<T> where T : Singleton<T>, new()
{
    private static T instance;
    public static T Instance
    {
        get
        {
            if (instance == null)
                instance = new T();
            return instance;
        }
        private set { }
    }

}