将通用接口参数类型转换为通用类类型

Question

I'm trying to learn about Generics, Interfaces and Polymorphism.

I am creating a Pool of objects and I want those objects to conform to the Generic Interface so I can tell them to return to their respective pools.

I have created the Generic Interface that accepts a Generic Type and a Generic Class.

public interface IWidgetPoolObject<T> {
    void ReturnToPool();
    void SetPool(T pool);
}


public class WidgetPool<T> : MonoBehaviour where T : MonoBehaviour {
    private List<T> m_poolList;

    public T GetObject() {
        //..
    }

    public void PoolObject(T pooledObject) {
        //..
    }
}

In the below example, inside the Interface Method SetPool(T pool) , I am trying to set the classes pool. But I am getting the can't cast to type error.

I recognize that SomeClass 's private member var is of type WidgetPool<SomeClass> and that SetPool is just passing in a type of SomeClass . But when I try casting m_Pool = (WidgetPool<SomeClass>) pool; that doesn't work either.

public class SomeClass : MonoBehaviour, IWidgetPoolObject<SomeClass> {

    private WidgetPool<SomeClass> m_Pool;

    public void ReturnToPool() {
        m_Pool.PoolObject(this);
    }

    public void SetPool(SomeClass pool) {
        m_Pool = pool; //THIS LINE
    }
}

I don't know enough yet to properly search what my issue would be. Any help?

Answer 1

Pool has type SomeClass while m_Pool has type WidgetPool ... you can't cast completely different types as you can't cast an integer to an array...that would not work at runtime. Maybe what you want to do is to create a new WidgetPool of a class SomeClass like that:

m_Pool= new WidgetPool<SomeClass>();
m_Pool.SetPool(pool);

... that would work...it depends on what you want to do...