C# generics - without lower bounds by design?

Question

I was reading an interview with Joshua Bloch in Coders at Work, where he lamented the introduction of generics in Java 5. He doesn\'t like the specific implementation largel

Answer 1

.net already has the equivalent of wildcards, more logically named generic type constraints, you can do what you describe with no problems

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
         List a = new List();
         List b = new List();
         List c = new List();
         test(a);
         test(b);
         test(c);

        }

        static void test(List a) where T : a
        {
            return;
        }
    }
    class a
    {

    }
    class b : a
    {

    }
    class c : b
    {

    }
}

Example 2

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            ICollection src = new List();
        ICollection dst = new List();
         copyAssets(src, dst);
        }

        public static void copyAssets(ICollection src, ICollection dst) where T : G {
            foreach(T asset in src) 
                dst.Add(asset);
        }
    }
    public class Asset {}
    public class Derivative : Asset {}
    public class VanillaOption : Derivative {}
}

This example represents a code conversion from your example in java.

I'm not really in a position to answer the actual question though!