StructureMap: Configure concrete classes at run time?

I know that Concrete Types can be configured with Structure Map the following way:

ForRequestedType<Rule>().TheDefault.Is.Object(new ColorRule("Green"));

This works if you kn开发者_运维知识库ow the type ahead of time. I want to do it at run time, and there does not seem to be a way. Can some one enlighten me? What I want to do is something like the following: (This appears to be not supported by structure map)

ForRequestedType(typeof(Rule)).TheDefault.Is.Object(new ColorRule("Green"));

The reason for this is because I'm working on a wrapper for structure-map's configuration. And I will not know the type ahead of time. For the .Object(new ColorRule("Green")) I am going to be passing in a delegate instead, which would actually construct the object on request.

Recently Jeremy added the ability to configure a Func as a builder for your type. Here is an example of using a delegate/lambda as your builder.

    public interface IRule
{
    string Color { get; set; }
}

public class ColorfulRule : IRule
{
    public string Color { get; set; }

    public ColorfulRule(string color)
    {
        Color = color;
    }
}

[TestFixture]
public class configuring_delegates
{
    [Test]
    public void test()
    {
        var color = "green";
        Func<IRule> builder = () => new ColorfulRule(color);

        var container = new Container(cfg=>
        {
            cfg.For<IRule>().Use(builder);
        });

        container.GetInstance<IRule>().Color.ShouldEqual("green");

        color = "blue";

        container.GetInstance<IRule>().Color.ShouldEqual("blue");
    }
}