generic of generic

Question

I've a generic base class where generic type is class and other related inherited class:

public class BaseClass<T> where T : class 
{
   virtual void DoWork(){..}
   virtual void DoAnotherWork(){..}
}

public class SomeInherit<Person> : BaseClass<Person>
{
   //...
}

public class OtherInherit<Car> : BaseClass<Car>
{
   // override something..
}

Then, I've a BaseClassManager which should be able to load some BaseClass inherited by some co-worker via reflection:

public class BaseClassManager
{
   public BaseClass<TItem> LoadBaseClass<T>() where T : BaseClass<???>
   {
      //  how can create an instance of T?
      //  TItem : class
      //  T : BaseClass
      //  -------------> in reality, it should be: T<TItem> (just as BaseClass<Person>)
   }
}

Is there any way to accomplish that..?

Answer 1

You need to define a second type parameter for where T : BaseClass<???>.
You can use the new() constraint to allow the method to create instances of a generic type.

public TBaseClass LoadBaseClass<TBaseClass, TItem>()
    where TBaseClass : BaseClass<TItem>, new()
    where TItem : class
{
    return new TBaseClass();
}

Usage:

SomeInherit<Foo> result = LoadBaseClass<SomeInherit<Foo>, Foo>();