How to know whether to use function or delegate

[Reiner Pope]

> Example #3 - You can still use it with a function, by wrapping it in an 
> anonymous delegate:
> # void bar (int a) {
> #   /*do stuff*/
> # }
> #
> # foo((int a) {
> #   bar(a);
> # });
Is it really necessary to *wrap* it? I'm surprised there isn't a cast to 
do it.