I created a specialization for a generic like code below:

public class BaseGeneric<T>
{
    public static T DoStuff()
        => default;
}

public class SpecializedFromBaseGeneric : BaseGeneric<int>
{
    public static new int DoStuff()
        => 789;
}

Now to call the DoStuff() method I would like to use var result = BaseGeneric<int>.DoStuff();

When I run this code, result is 0 instead of 789. The debugger shows that the call will enter the DoStuff() from public class BaseGeneric<T> instead of SpecializedFromBaseGeneric.

What am I doing wrong?

Later edit

I also tried to create specialization in the below format but that does not even compile:

public class BaseGeneric<T> where T : int
{
    public static T DoStuff()
        => 789;
}

I want to do several specializations and use the call similar to the one specified above for int data type BaseGeneric<int>.DoStuff(). And for each specialization use the same syntax where only data type is changed but different implementation is used (eg: for string that would be BaseGeneric<string>.DoStuff()). How to achieve this behaviour?

CodePudding user response：

    public class BaseGeneric<T> where T : IConvertible
    {
        public static T DoStuff()
        {
            if (typeof(T) == typeof(int))
            {
                return (T)(object)789;
            }

            if (typeof(T) == typeof(string))
            {
                return (T)(object)"ss";
            }

            return default(T);
        }
    }

However, as the asnwer here suggests, this is brittle, and doesn't cover every possible usage.

CodePudding user response：

var result = BaseGeneric<int>.DoStuff()

This one calls the function of a base class. It returns new T(), that equals new int(), that equals zero.

var result = SpecializedFromBaseGeneric.DoStuff()

This one will return what you need.