StackOverflowException with composite/contravariance

[WolfgangKluge]

Hi,

this might be linked to #465.

I'm still trying to get the composition-pattern to work and I realized, that I can get it somewhat to work, if I don't use open generics.

void CompositeTest() {
    using (var container = new ServiceContainer()) {
        container.Register<Foo>();
        container.Register<FooBar>();
        container.Register<Bar>();

        container.Register<IFoo<A>, Composite<A>>();
        container.Register<IFoo<B>, Composite<B>>();
        
        container.GetInstance<IFoo<A>>();
        container.GetInstance<IFoo<B>>(); // StackOverflowException
    }
}


interface A { }
interface B : A { }

interface IFoo<in T> { }

class Foo : IFoo<A> { }
class FooBar : IFoo<A> { }
class Bar : IFoo<B> { }

class Composite<T> : IFoo<T> {
    public Composite(IEnumerable<IFoo<T>> foos) {
    }
}

This works perfect, if I remove the in-Keyword from the IFoo<>-interface. But then in container.GetInstance<IFoo<B>>() there's only one instance (Bar since it's IFoo<B>). I expect all 3 instances..

My workaround is to not register/use the composite-pattern and use container.GetAllInstances<IFoo<B>>() instead. That one works with contravariance (returns 3 instances with and 1 without contracvariance).

• Version: 5.3.0
• Platform: WIndows 10 / .net 4.7.3221.0