public static class IntExtensions {

    /// <summary>
    /// 
    /// </summary>
    /// <param name="a"></param>
    /// <param name="b"></param>
    /// <returns></returns>
    public static bool HasFlag (this int a, int b) { return (a & b) == b; }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="a"></param>
    /// <param name="b"></param>
    /// <returns></returns>
    public static int AddFlag (this int a, int b) { return a |= b; }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="a"></param>
    /// <param name="b"></param>
    /// <returns></returns>
    public static int RemoveFlag (this int a, int b) { return a &= ~b; }
}