Rand

[System.Serializable]
public class RandFloat : Rand<float>
{
    public RandFloat(float min, float max) : base(min, max){ }
    protected override float _rand(float min, float max) { return UnityEngine.Random.Range(min, max); }
}

[System.Serializable]
public class RandInt : Rand<int>
{
    public RandInt(int min, int max) : base(min, max){ }
    protected override int _rand(int min, int max) { return UnityEngine.Random.Range(min, max+1); }
}

public abstract class Rand<T> where T: struct
{ 
    public T _min;
    public T _max;
    T? _value;

    public T value { get { return _value ?? Calc(); } }


    public Rand() { }
    public Rand(T min, T max) { _min = min;  _max = max; }

    public T Calc()
    {
        _value = _rand(_min, _max);
        return _value.Value;
    }

    protected abstract T _rand(T min, T max);
}