Resolution status in DryIoc container - dryioc

Question

Is it possible in DryIoc container to figure out whether some singleton has been instantiated?
For instance
var container = new Container();
container.Register<IApplicationContext, ApplicationContext>( Reuse.Singleton );
// var context = container.Resolve<IApplicationContext>();
if ( container.IsInstantiated<IApplicationContext>() ) // Apparently this does not compile
{
// ...
}
// OR
if ( container.IsInstantiated<ApplicationContext>() )
{
// ...
}

Answer 1

There is no way at the moment and no such feature planned. You may create an issue to request this.
But I am wandering why it is needed. Cause singleton provides a guarantee to be created only once, so you may not worry or check for double creation.
Is it for something else?
Update
OK, in DryIoc you may register a "decorator" to control and provide information about decoratee creation, here is more on decorators:
[TestFixture]
public class SO_IsInstantiatedViaDecorator
{
[Test]
public void Test()
{
var c = new Container();
c.Register<IService, X>(Reuse.Singleton);
c.Register<XProvider>(Reuse.Singleton);
c.Register<IService>(
Made.Of(_ => ServiceInfo.Of<XProvider>(), p => p.Create(Arg.Of<Func<IService>>())),
Reuse.Singleton,
Setup.Decorator);
c.Register<A>();
var x = c.Resolve<XProvider>();
Assert.IsFalse(x.IsCreated);
c.Resolve<A>();
Assert.IsTrue(x.IsCreated);
}
public interface IService { }
public class X : IService { }
public class A
{
public A(IService service) { }
}
public class XProvider
{
public bool IsCreated { get; private set; }
public IService Create(Func<IService> factory)
{
IsCreated = true;
return factory();
}
}
}
This example also illustrates how powerful is composition of DryIoc decorators and factory methods.