State manager using generic enums

EnumState.cs

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

/// <summary>
/// https://docs.microsoft.com/fr-fr/dotnet/csharp/language-reference/operators/user-defined-conversion-operators
/// </summary>
[System.Serializable]
public class EnumState<TState> where TState : System.Enum
{
    System.Action<TState> binds;

    [ReadOnly]
    [SerializeField]
    TState _state;

    public EnumState()
    { }

    public EnumState(IStateReactor<TState> client)
    {
        Debug.Assert(client != null);

        Debug.Log("creating state for " + client);

        bind(client);

        //changeState(default(TState));
        triggerState(default(TState));
    }

    public static implicit operator TState(EnumState<TState> v) => v.getValue();
    //public static explicit operator TState(EnumState<TState> v) => v.getValue();

    public void bind(IStateReactor<TState> client)
    {
        Debug.Assert(client != null, "no client given for binding ?");

        binds += client.stateChanged;

        BrainBase bb = client as BrainBase;
        if (bb != null)
        {
            KappaAppearance kap = bb.getCapacity<KappaAppearance>();
            if (kap != null)
            {
                IStateReactor<TState> ikap = kap as IStateReactor<TState>;
                if (ikap != null) bind(ikap);
                else Debug.LogWarning(kap.name + " is not a state reactor", kap);
            }
            else Debug.LogWarning("no kapp on " + bb, bb);
        }
    }

    public void bind(System.Action<TState> callback)
    {
        binds += callback;
    }

    /// <summary>
    /// https://stackoverflow.com/questions/6480577/how-to-compare-values-of-generic-types
    /// </summary>
    /// <param name="newState"></param>
    public void changeState(TState newState)
    {
        if (newState.CompareTo(_state) == 0) return; // same value

        triggerState(newState);
    }

    void triggerState(TState newState)
    {
        _state = newState;

        binds?.Invoke(_state);
    }

    public bool same(TState other) => _state.CompareTo(other) == 0;

    public TState getValue() => _state;
    //public T getState() => (T)System.Enum.GetValues(typeof(T)).GetValue(_state);
}

public interface IStateReactor<TState> where TState : System.Enum
{
    void stateChanged(TState state);
}