Rule for resolving with delegate as default?

[zplan]

I am switching from Unity to DryIoc. Now I have seen a different behavior between these twos:

Works with Unity, but not with DryIoc

var container = new Container();

container.RegisterDelegate(_ => new CheerfulService { Greetings = "Hey!" });

container.Register<IFoo, CheerfulService>(); // with Unity I can just register interface -> type and it resolves with the factory above

var x = container.Resolve<IFoo>();
Assert.AreEqual("Hey!", x.Greetings); // with DryIoc I have here another instance than the one from the RegisterDelegate

Works with DryIoc

var container = new Container();

container.RegisterDelegate(_ => new CheerfulService { Greetings = "Hey!" });

container.RegisterDelegate<IFoo>(c => c.Resolve<CheerfulService>()); // with DryIoc I have to use another RegisterDelegate, otherwise the RegisterDelegate above is not applied

var x = container.Resolve<IFoo>();
Assert.AreEqual("Hey!", x.Greetings);

Is there a Container rule which allows to make the first option to work?

Thanks for feedback.

[dadhi]

Try this:

container.RegisterDelegate<IFoo>(_ => new CheerfulService { Greetings = "Hey!" });

[zplan]

Thanks.
Yes, this I could do. But since I have hundreds of existing unity registrations it would have been easier keeping the logic of those and make them "just" work with a rule.
So it looks like I have "a little" refactoring task ahead of me 😄

[dadhi]

I wonder, so the Unity registers the delegate for the interfaces implemented by its return type, right?
You probably may emulate it with the sugar over the RegisterMany as following:

public static void RegisterDelegate<TImplType>(Func<IResolverContext, TImplType> @delegate, IReuse reuse = null) =>
     RegisterMany(
        implTypes: new[] { typeof(TImplType) }, 
        getServiceTypes: implType => implType.GetRegisterManyImplementedServiceTypes(nonPublicServiceTypes: true),
        getImplFactory: _ => DelegateFactory.Of(@delegate.ToFactoryDelegate, reuse)
     );