Better way to call overloaded functions with more-derived parameters, passing in less-derived types

Question

I have 16 methods that take two parameters, and each of the two parameters can be either an \'Insertion\' or a \'Deletion\', both of which implement IFragment. I also have four

Answer 1

I've implemented DynamicDispatcher.cs which fulfills this need.

It uses reflection and a stack trace (a single one on construction) to generate a tree of overloads by parameter types. It handles bidirectional casting on base classes and implemented interfaces.

Since it's part of a larger project and doesn't have any documentation, here's an example use (from the same project):

    public static void DeleteTreeNodeChild(BehaviorTree.Choice parentNode, BehaviorTree.Node childNode) {
        parentNode.Children.Remove(childNode);
    }

    public static void DeleteTreeNodeChild(BehaviorTree.Optional parentNode, BehaviorTree.Node childNode) {
        Debug.Assert(parentNode.Child == childNode);
        parentNode.Child = null;
    }

    public static void DeleteTreeNodeChild(BehaviorTree.Repetition parentNode, BehaviorTree.Node childNode) {
        Debug.Assert(parentNode.Child == childNode);
        parentNode.Child = null;
    }

    public static void DeleteTreeNodeChild(BehaviorTree.Sequence parentNode, BehaviorTree.Node childNode) {
        parentNode.Children.Remove(childNode);
    }

    private static DynamicDispatcher _deleteTreeNodeChildDynamicDispatcher;
    public static void DeleteTreeNodeChild(BehaviorTree.Node parentNode, BehaviorTree.Node childNode) {
        if (_deleteTreeNodeChildDynamicDispatcher == null) {
            _deleteTreeNodeChildDynamicDispatcher = new DynamicDispatcher();
        }
        _deleteTreeNodeChildDynamicDispatcher.Dispatch<Object>(null, parentNode, childNode);
    }

Answer 2

First of all, you can't call a method with objects that are "less derived" since the method you are calling is waiting for a minimum requirements from this type.

For this type of problem, I think it's better just using different names for that function. "IntroduceAntecedent" should exist along with "IntroduceAntecedent_DelDel" and all 3 other combinaisons. That's clearly my own opinion, but The way you did it seems ok for what you would expect it to do.