Restricting T to string and int?

Question

I have built myself a generic collection class which is defined like this.

public class StatisticItemHits<T>{...} 

This class can be used with int and string values only. However this

public class StatisticItemHits<T> where T : string, int {...} 

won't compile. What am I doing wrong?

Answer 1

The type restriction is meant to be used with Interfaces. Your sample suggests that you want to allow classes that inherit from int and string, which is kinda nonsense. I suggest you design an interface that contains the methods you'll be using in your generic class StatisticItemHits, and use that interface as restriction. However I don't really see your requirements here, maybe you could post some more details about your scenario?

Answer 2

You could make StatisticItemHits<T> an abstract class and create two subclasses:

StatisticItemHitsInt : StatisticItemHits<int>{}

StatisticItemHitsString : StatisticItemHits<string>{}

That way there can only be an int and string-representation of StatisticItemHits