title: How to represent integer infinity?
body: <p>I need a way to represent an integer number that can be infinite. I'd prefer not to use a floating point type (double.PositiveInfinity) since the number can never be fractional and this might make the API confusing. What is the best way to do this?</p>
  
  <p>Edit: One idea I haven't seen yet is using int? with null representing infinity. Are there any good reasons not to do this?</p>