Commonly used math functions not included in unity

MathUtils.cs

using UnityEngine;
using System.Collections;

public static class MathUtils
{
	public const float TAU = Mathf.PI * 2;

	public static float MoveTowards (float current, float goal, float amount)
	{
		var delta = goal - current;
		if (delta < 0) {
			if (-delta < amount)
				return goal;			
			return current - amount;
		}		
		if (delta < amount)
			return goal;
		return current + amount;
	}
	
	public static double Clamp01 (double d)
	{
		if (d < 0)
			return 0;
		if (d > 1)
			return 1;
		return d;
	}

	public static float ClampRotation (float angle, float minAngle, float maxAngle)
	{
		if (angle > 180)
			angle -= 360;

		if (minAngle > 180)
			minAngle -= 360;

		if (maxAngle > 180)
			maxAngle -= 360;

		return Mathf.Clamp (angle, minAngle, maxAngle);
	}
}

Clamp01 exists since Unity 5.2: https://docs.unity3d.com/520/Documentation/ScriptReference/Mathf.html 😉

Clamp01 exists since Unity 5.2: https://docs.unity3d.com/520/Documentation/ScriptReference/Mathf.html 😉

Yes and it's great, however this version supports the double type, which Unity's doesn't.
Stay Safe!