I know it may seem odd, but type DISTANCE_TYPE is actually better than int. Type int just means its 8 bit, but type DISTANCE_TYPE is in centimeters (as far as the programmer should be concerned).
The advantage is that you don't need to be concerned with the returned file types of different sensors. For one sensor its not that big a deal, but when you have say five sensors, it could get confusing.
For example, lets say your robot has a sharp IR and a sonar, and you need to compare distances . . . well, they both will return a value in DISTANCE_TYPE, meaning the final result for both is in centimeters. You don't need to worry about unit conversions, or one sensor being 16 bit while the other is 8 bit, or what type to output with rprintf, etc.