Serializing a Function in Unity using AnimationCurve

public interface ICurve
{
    float Evaluate(float t);
}

public struct NormalCurve : ICurve
{
    readonly float width;
    readonly float maxValue;
    readonly float minValue;

    public NormalCurve(float width, float min, float max)
    {
        this.width = width;
        maxValue = max;
        minValue = min;
    }

    public float Evaluate(float value)
    {
        return Mathf.Max(
            Mathf.Exp(-Mathf.Pow(value, 2f) / width) * (maxValue - minValue) +
            minValue - 0.01f,
        minValue);
    }
}

public struct PropulsionCurve : ICurve
{
    public float maxVelocity;
    public float maxForce;

    private readonly float coefficient;

    public PropulsionCurve(float v_max = 100f, float f_max = 5f)
    {
        maxVelocity = v_max;
        maxForce = f_max;
        coefficient = f_max / (v_max * v_max);
    }

    public float Evaluate(float x) => Mathf.Min(coefficient * x * x, maxForce);
}