A serializable struct wrapper for smooth damping. Debug inspector will show you Current Value and Velocity!

SmoothDampState.cs

using System;
using UnityEngine;

[Serializable]
public struct SmoothDampState
{
    #region Fields

    public float Damping;

    public float MaxSpeed;

    #endregion

    #region Properties

    public float TargetValue { get; set; }

    public float CurrentValue { get; set; }

    public float Velocity { get; set; }

    #endregion

    #region Methods

    public SmoothDampState IntegrateNewState()
    {
        return IntegrateNewState(Time.deltaTime);
    }

    public SmoothDampState IntegrateNewState(float dt)
    {
        var copy = this;
        var currentVelocity = Velocity;
        copy.CurrentValue = Mathf.SmoothDamp(CurrentValue, TargetValue, ref currentVelocity, Damping, MaxSpeed, dt);
        copy.Velocity = currentVelocity;
        return copy;
    }

    #endregion
}