Lazy initialization of an object using reflection

Question

I would like to do lazy initialization of the below call. I know the type of T while constructing the object.

T facade = (T)Activator.CreateInstance(typeof(T), param);

Is there a way to achieve this?

Answer 1

You could subclass Lazy<T>, like this:

public class LazyActivator<T> : Lazy<T>
{
    public LazyActivator(params object[] args) : base(() => (T)Activator.CreateInstance(typeof(T), args))
    {
    }
}

then:

LazyActivator<List<int>> lazyList = new LazyActivator<List<int>>(5);

and if you need the List<int> (that has Capacity == 5)

List<int> list = lazyList.Value;