LayerMaskExtensions.cs

using UnityEngine;
using System.Collections;

public static class LayerMaskExtensions {
    public static bool LayerInMask(this LayerMask layerMask, int layer) {
        return (layerMask & (1 << layer)) > 0;
    }
    public static bool LayerInMask(this LayerMask layerMask, GameObject gameObject) {
        return (layerMask & (1 << gameObject.layer)) > 0;
    }
}