NullOrEmptyString

 public static bool operator==(NullOrEmptyString s1, string s2)
 {
  return ((object)s1) == null || s1.Equals(s2);
 }
 public static bool operator!=(NullOrEmptyString s1, string s2)
 {
  return !(((object)s1) == null || s1.Equals(s2));
 }
 public override int GetHashCode()
 {
  return String.Empty.GetHashCode();
 }
 public override bool Equals(object o)
 {
  return((o is string) && (o == null || (((string)o) == string.Empty)));
 }
 public static implicit operator string(NullOrEmptyString s)
 {
  return s.ToString();
 }
 public override string ToString()
 {
  return String.Empty;
 }
}