idle-survivors/Assets/Scripts/RuntimeSetSO.cs

using System.Collections.Generic;
using UnityEngine;

public abstract class RuntimeSetSO<T> : ScriptableObject
{
    [HideInInspector] [SerializeField] private List<T> items = new();
    
    public IReadOnlyCollection<T> Items => items;
    public bool IsEmpty => items.Count == 0;
    
    public void Add(T thing)
    {
        if (!items.Contains(thing))
        {
            items.Add(thing);
        }
    }
    
    public void Remove(T thing)
    {
        if (items.Contains(thing))
        {
            items.Remove(thing);
        }
    }
}