I learnt this weekend it is possible to create a delegate that also implements an interface. Why would this be handy? By providing your own ‘overloads’ in this, you can effectively alter the delegate’s ‘calling convention’, without resorting to reflection.

Pseudo example:

interface IFunction
{
  object Invoke(object arg);
  object Invoke(object[] args);
}

delegate object Function(object arg) : IFunction;

 
Now in the background, I emit the following code for the ‘overload’ in the delegate class:

object IFunction.Invoke(object[] args)
{
  return this(args[0]);
}

 
Now we can simply cast a delegate of type Function, to IFunction, and call it with an array.